Evolution Debates 2002
There are two main theories, which are: Ground Up Scenario, and Trees Down Scenario. The Ground Up Scenario is the flight must have proceeded from grounded into air. The Trees Down Scenario is the leaping of trees that provide the acceleration and the speed necessary for flight. If the ancestor was a glider, its gliding structure tuned into wings. It had to flap its gliding membrane. If the ancestor was not a glider then its wings must have developed from another function of the air. Mammals, Reptiles, and Birds all evolve around the same things such as flight. Flight evolved millions of years ago in all of the groups, which are capable of flight today,
There are two main theories, which are, Ground Up Scenario, and Trees Down Scenario. The Ground Up Scenario theory is that the flight must have proceeded from grounded into air. The Trees Down Scenario theory is the leaping of trees that provide the acceleration and the speed necessary for flight. If the ancestor was a glider, its gliding structure tuned into wings. It had to flap its gliding membrane. If the ancestor was not a glider then its wings musty have developed from another function of the air. Mammals, Reptiles, and Birds all evolve around the same things such as flight. Flight had evolves millions of years ago in all of the groups, which are capable of flight today. The most amazing fact about the evolution of flight is the extent of convergent evolution between the three main groups that evolved it which are the pterosaurs, birds, and bats. Flight muscles stretch from the wing to the breast bone. A bird must be light in order to fly, which means birds have no teeth, either they tare the food with teeth or they eat only food they can swallow. The bones are fused (reduced in size) reducing mass of skeleton and distributes mass to center of body. Feathers provide lift to fly. Feathers have maximal flexibility and strength with minimal weight. Counter feathers cover body and wings, it often asymmetrical, and provides an aerodynamic shape to wings. Microscopic hooks give these feathers flexibility and strength. Down feathers are the ones with no hooks, it primary function is to insulate. When ends of feathers disintegrate, it is known as power down. Power down is known to cause things to be water proof. It mostly occurs on herons, parrots, and hawks. Semiphores crosses between contour and down feathers. It lies beneath down feathers. It provides insulation and it helps the birds to be more aerodynamic. Filplumes are long and hair like. It has sensory Corpuscles which lets birds know the levitation of its feathers during flight. Bristles only have a few hooks, found around eyes and nostrils and corners of mouth Maybe to sense positron of prey.
Ground Up Scenario: Given a bipedal cursorial (running) ancestor of a flying lineage, flight must have proceeded from the ground into the air, assuming that the ancestor did not normally live in trees, or if there were no trees around. We know from extant (living) animals that gliding is mainly useful from the trees, so we can be fairly safe in ruling out a gliding ancestor in this case. A quadrupedal al ancestor would have problems evolving flight from the ground up; it would have to be able to be bipedal in order to use its wings at all! A cursorial bipedal animal would have its arms free to do with them a while running, and its running speed would allow it to achieve the minimum speed necessary for liftoff.
Birds wouldn't have enough energy
Evolution of flight has two main theories, which are ground up scenario and trees down scenario. The ground up scenario is flight must have proceeded from ground into air. The trees down scenario is when they leap off trees would provide acceleration and speed necessary for flight. Its ancestor was a glider and their gliding structure turned into wings. It had to flap its gliding membrane and if the ancestor wasn't a glider then its wings must have developed from another function of the air. Flight evolved for many reasons. They evolved to escape from predators, to catch flying or speeding prey, to help move from place to place, to free hind legs for use as weapons, to gain new food sources or an unoccupied niche. Feathers provide lift for birds to fly. Feathers have maximal flexibility and strength with minimal weight. There are Contour Feathers, Down Feathers, Semiplunes, Filoplumes, Bristles, etc. Contour Feathers cover the body and wing. It often is asymmetrical and provides an aerodynamic shape to wings. Microscopic hooks give these feathers flexibility and strength. Down Feathers has no hooks and their primary function is to insulate. Semiplumes cross between contour and down feathers. It provides insulation and helps the bird to be more aerodynamic. Filoplumes are long and hair like. They have sensory corpuscles at the base of each one that lets the bird know the position of each feather. Bristles only have a few hooks. Bristles are found around the eyes, their nostrils, and corners of their mouth. Every bird has its own features that help him or her fly. Muscles stretch from the wing to breastbone. To fly birds also must be light so birds have no teeth. In order for them to eat they either tear food with beak or they only eat food that they could just swallow as a whole. Bones are also fused (reduce in size) reducing mass of skeleton and distributes mass of centre of body. Birds are endothermic. It is high temperature permits metabolism in bird's flight muscles. Rapid metabolism is needed to satisfy the large energy requirements for flight.
The birds have many different abilities to help it fly. Feathers provide lift for birds to fly, because the feathers have maximum amount of flexibility and strength with the most minimum amount of weight. There are different kinds of feathers, one kind is the Contour Feather, it covers' the bird's body and wings. Contour Feathers are often asymmetrical, and provide an aerodynamic shape for the wings. Down Feathers have no hooks, and the primary function of it is to insulate heat. These Down Feathers occur in herons, parrots, and hawks. The Semiplumes is a cross between the Contour and Down Feathers. It lies beneath the Down Feathers. It provides insulation and more aerodynamic than the Down Feathers. The Filoplumes are long and hair-like. It has sensory corpuscles to let birds know where the location of it's feathers during flight. Bristles have a few hooks. Bristles are mainly found around the eyes, nostrils, and the corners of its mouth. For birds to fly, the muscles must be stretched from the wing to breastbone. Bird's head cannot be heavy, so they have no teeth. Birds must eat food that they can swallow whole, or they have to tear the food with their beaks. The bird's bones are fused together, to reduce size and distribute all the mass to the center of the body. Birds are endothermic, the high temperature permits metabolism in the bird's flight muscles. The rapid metabolism is needed to satisfy the large energy requirements for flight.
The ground up scenario flight must have proceeded from ground into air. The trees down scenario leaping off trees would provide the acceleration and speed necessary for flight. If the ancestor was a glider it's gliding structure turned into wings. If the ancestors were not a glider then its wings must have developed from another function of the air. The used the evolution of flight to escape from predators, to catch flying or speeding prey, to help move place to place, to free hind legs for use as weapons, and to gain access to new food sources. The lack of teeth in birds is cause the birds head needs to be light for the to fly. A bird's skeleton is designed for flight; many bones are fused, or reduced in size, reducing the mass of the skeleton, and redistributing mass towards the centre of the body. Many bones in a bird's body are pneumatized, meaning that they contain large air pockets that are connected to the repertory system. Bird bones therefore are very light.
The vertebate of flight consist if two main theories and thoose theories are ground up and tress down. Ground up consist of flight having to proceed from ground into air. Tress down consist of leaping off tress by that prosses that would provide the acceleration and speed necessary for flight. Flight evolved for a couple of reasons such as escaping from predators, catch flying or speeding prey, to move from place to place, to free hind legs for use as weapons, to gain access to new food sources or an unoccupied niche. That is what flight is mainly used for. The feathers are used with maximal flexibility and strenth with a little weight. The power of flight comes from the large breast muscles. The muscles get most of it's strenth from the wing to the breast bone. High temperature permits metabolism in birds flight muscles. Rapid metabolism is needed to satisfy the large energy requirements for flight. Feathers have evolved from reptitian scales which are composed of keratain and is complexed in structure. There are five different kinds of featers which are contour, down, semiplumes, filoplumes and bristles each as it's different shape and stucture. The contour featers cover the body and wings. They provide an aerodymamic shape to the wings. The contour feathers has both flexible and strength. The down feather has a simple structure their primary function is as insulation. These feathers produce an aid such as water proofing and grooming. This prosses is called powder down birds such as herons, parrots, and hawks have it. The semiplumes provides insulation and makes the bird more aerodynaic. The filoplume feathers are long and hair like also are sensory in function. The sensory corpuscles are located at the base of each filoplume. The bristle feathers only have a few hooks and barbules. The feathers are found around the eyes, nostrils and at the comers known as the ricta of the mouth. Usally the birds use the ricta bristles to sense position of prey.
Evolution of flight muscles consumes 30 percent of the body's capacity. Mutation led to the wings o evolution. Archaeopteryx is 150 million years old, which is the oldest bird around. They have an attachment for flying muscles. They also need their wishbone to help them fly. Although they came about 150 million years ago they did not become known until the pterosaurus became extinct. Birds and dinosaurs have so many similarities to one another except for the feathers. Scientists say birds are feathered dinosaurs. Early birds had theeth but modern birds don't. Although modern birds and early birds have some simularitys, they are still unique in their own ways. Bats are the second group of mammals to evolve true powered flight. Bats came about from it's ancestor 60-65 million years ago. Scientist are still not sure that Chiroptera is a proper Monophylotic group. A guess has been made that they came from two different ancestors, if that is true it means that mammals evolved twice in flight and for times in vertebrates. The first vertebrates that evolved were the flying reptiles. In the 18th century the fossils Pterosaurs was discovered but they thought it was a failed experiment in flight. However they lasted for 140 million years. It takes alot for a pigeon to adapt to flying. It has a big breast bone and just like the Archaeopteryx's they have a lot of bone attachment for flying. Flight was evolved to escape predators, get food, travel, and to get more acces to food sources. Wings came about from arms. Their also known as a sexual structure. Inorder for you to get wings your ancestor behaviors ment something and so did their adaptions.
As from the resources from starsandseas.com (Mr. Hartzogs web site) said pterodactyls probably hunted its prey by gliding toward the water and swooping up its meals
The latter theory posits that tree climbing dinosaurs evolved mechanisms to glide from trees or other elevations to some distance away from that spot, landing on the ground. While the latter is more attractive than the prior on the surface level, the prior theory is most likely the correct theory. Most paleontologists of the 19th and early 20th centuries agreed that they could fly to some extent, though not necessarily as capable as today's birds and bats. After the 1920's, opinion seemed to go downhill: namely, that they were mere gliders, with weak, flimsy wings that easily suffered debilitating tears. With the growing popularity in the last few decades of the image of dinosaurs as agile, possibly warm-blooded animals, pterosaurs have been recognized as powered, highly successful flyers. The pterosaur body was highly adapted to enduring the rigors of flight. Many bones are fused together, providing a sturdy framework for the muscles and other organs. The pelvic vertebrae had in fact fused with the pelvic bones, providing a shock-absorbing structure (the synsacrum) that braced the animal when it landed. In larger pterosaurs, the pectoral vertebrae were similarly fused in a structure called the notarium. The sternum, or breastbone, had a keel that provided an attachment for large pectoral muscles, and a forward projection, the cristospine, may have functioned much like the furcula ("wishbone") in birds. Many rhamphorhynchoid fossils show the outline of a flap of skin at the tip of the tail that may have acted as a rudder, and the neural spines were likewise elongated in some. In order to reduce weight, pterosaur bones were hollow; indeed, they were even thinner than many avian bones. The later pterodactyloids, as mentioned earlier, lost all traces of teeth and may have had horny beaks. Most likely they were. Active flight is a strenous activity, and any creature that wants to fly must have a high metabolism. Birds and bats are definitely warm-blooded; the presence of fur, and the adaptations for flight that pterosaurs undertook surely imply that they were warm-blooded.
Bats, also known as Chiropterans are the second most diverse groups of mammals to evolve the power of flight. You can see the striking resemblance between the archaeopteryx. The skeleton structure and organ placement is very similar. Even though there were only 7 archaeopteryx and bats still live today, a much simpler comparison can be made between the archaeopteryx and the modern day chicken. The bone structure is very similar and the wishbone has formed to give the bird a slight lift. However chickens cannot fly. An ancient flyer like the archaeopteryx, the pterosaur, was the first animal to obtain the power of flight as we know. Wings and feathers were developed for various reasons scientists believe. They were used to catch small prey, gliding from tree to tree or to obtain lift of the ground while running at high speeds. The archaeopteryx is about 150 million years old. Its wishbone showed that it could indeed fly. This bird/ dinosaur had teeth and had a very long tail. It had a collar bone to help absorb the stress from flying.
How flight is evolved in a group depends on what ancestor's behavior and adaptations on the environment. Wings were evolved by gliding ancestors who began to flex and produce thrust. Wings were exaptation and decendents used them for flying. The reasons for wings is because they were used to catch small prey, gave them ability to leap, and sexual display structure. Wings were evolved because of small bipedal animals leaped which wings assisted leaping. Running ancestors of flying lineage show that flight was from ground up and that gliding began from top of trees which they would glide downward. If the species were to fly from straight ground then it would have to spread its arms free while running and the speed would began giving the specie flight. Arboreal ancestors of flying lineage went from trees to the air like a semi-bipedal gliding animal that leaped off of tress to get acceleration. The wings on these species must have flopped to do flight. The evolution of flight was for the specie to escape from predators, catch prey, move from place to place, use free hindlegs for use of weapons, and to gain access to new food sources. Species such as Archaeopteryx, the oldest extinct bird is about 150 million years old and is believed to have started it all. The Archaeopteryx has enlarged breastbones that is enlarged and has a keel down the midline that provide solid attachment for flying muscles. It also has collarbone that links to the shoulder which provides itself for flight. This specie is also similar to the pigeon specie because both of them have big breast bone, collarbone, and has a lot of adaptations for flying.
The evolution of flight dates back to the dinosaurs. The first vertebrates to ever evolve flight were the pterosaurs that were flying archosaurian reptiles. However as a group the pterosaurs lasted about 140 million years meaning that flying may not have been adapted for escaping predators but for chasing prey and when it was all gone so were they. Birds such as Archaeoptery evolved from bipedal dinosaurs about 150 million years ago, it was not common until after the extinction of the pterosaur. However the two looked alike not counting the fact that one had feathers. The fact that Archaeoptery resembles pterosaur so closely could mean that they lived in the same conditions and so they had the same mutations but it most likely means that the two are related. There are many explanations for the evolution wings, some being they evolved from arms and were used as nets, they evolved to assist small bipedal animals in jumping, they were for sexual display, and they were for gliding. The one which seems the most reasonable based on the fact that the first bird evolved from a bipedal dinosaur is that they assisted bipedal animals in leaping and over time they learned to use them to fly, probably to get food, not be food or find a new, safer nesting place. The adaptation of flight would have added weight to each animal because it makes up about 30% of the body weight. Similarities between the archaeopteryx and modern birds are their feathers, their short tail bones and they all have a collar bone which is a torque absorbing strut linking the shoulders. However there are differences in that modern birds have an anchor flight muscle and hollow bones making them lighter for flight were, as early birds did not.
Paleontology has us understand the unique evoluti on ary history of birds. One of the bird are a bats are th e second most diverse group of mammals ever to evolve d true power for flying. It about 60-65 million year ago flying evolved twice in mammals are four times in verb reates. Another bird is Pterosauria one of the first vert ebrates to evolved true flying. One of the early bird is Archaeopteryx about 150 million years old .As the foss il was found scientists saw that it was involved from a small bipedal dinosaurs. This fossil is the most importa nt fossil ever discovered. Archaeopteryx had a full set of teeth, had a flat breastbone, a long bony tail, Gastra lia (belly ribs), and three claws on the wings that was used to get it prey or maybe trees. However, its feather s, wings, fucula (wishbone) and lest finger are the same characteristics as a modern bird. It breastbone is enlar ged, has a keel down the midline to fall over the sidew ays that provide a solid attachment for better flying mu scles. Having a good collarbone that is called wishbone The wishbone is links to the shoulders, wishbone is n ceded so it could fly. The fossil was found that it had a lot of feathers and it could help to be warm. A modern fossil bird is a pigeon- s that has a lot of adaptation fo r flying. Has a big breastbone, has a lot of bone attach ment point for flying muscles. Has a collarbone that it help it absorb the stressed of flying. It very skinny it 1 ooks gentle and it has a short tailbone sticking out and it short. These bones are very interesting and it helps us see the evolution on birds into the earliest bird to th e modern birds.
When we think of flight, we think of insects, pterosaurs, birds, and bats. What was about these species that helped them to master the arts of flying and why. We will take a journey through the evolution of flight and explore these flying species inside and outside to find out what it takes to fly. To study the evolution of flight, we must go all the way back to the Jurrasic period where we will find the earliest bird known today, the archaepterx. Living 150 million years ago, the archaepteryx's fossil was found in the site, Solenhofen Limestone in Bavaria, Germany. With features we find in modern birds today, the archaepteryx is classied as a bird. With no breastbone, it anchored its flight muscles. It had solid bones and a super effecient lung. Another key feature that seperates the archaepterx from all the other flying species of it's time is it's feathers. The known bird related to the oldest group of living birds are ostrich. In the early cretaceous period, evolution brings up ducks, geese and waterfowls. Then comes woodpecks, parrots, swifts, owls. During the mid cretaceous, passeriformes and songbirds evolve. Then comes shorebirds, birds of prey, flammingos, and penguins during the late cretaceous period. The one essential key factor in a bird is it's feathers. It provides lift and conserves heat. The feather is perfect for flight because of it's maximal flexibility. It gave birds strength with less weight. A feather is made up of tiny pits containing follides. A shaft emerges from the follide. Then Pairs of vanes are developed from opposite sides of the shaft. Each vane is consisting of barbs.
Flight is basically in insects, pterosaurs, birds, and bats. The feathers are from reptilian scales and are known as lightweight and easily replaced. One of the earliest flight creatures was Arcaetert which lived in Bavaria, Germany. The rock in that area is Solenhofen limestone and the area only know is about 150 millions years ago. The description about Arcahetert is that it had no breastbone, it only had solid bones, it did have feathers, anchor flight muscles, and it also had super efficient lung. The ostrich is known to have relatives belonging to the oldest group of living birds. Ducks, geese, and waterfowl have been around since the early Cretaceous period. Woodpeckers, parrots, swifts, owls, passerformes, and songbirds were around in the mid-Cretaceous period. And the flight animals around the late Cretaceous period were the shorebirds, birds of prey, flamingos, and penguins.
Currently, there are a lot of flying creatures in the world today. Although there are a large number of these creatures, not many classes in the animal kingdom have this feature. Flight was used successfully in insects, pterosaurs, birds, and bats. These are the only known creatures that we know of that have wins and the ability top fly. The most successful of these creatures is the bird, since they are found all over the world, across many different species, and in many different evolutionary forms. There are two main features of a bird that separates it from the other flying creatures: the use of feathers and the use of amniotic eggs. The feathers evolved from reptilian scales, are lightweight, and can be easily replaced. They were used to provide lift and also to conserve heat. Feathers provide maximal flexibility and strength in exchange for a lighter weight load. The feathers evolved from the scales that grew on a reptile's feet, on their lower legs The earliest type of bird was the Archaeopteryx. It was discovered in Bavaria, Germany in the Solahofen Limestone, approximately 150 million years ago. It had no breastbone, which anchored its flight muscles, and solid bones, which weighed it down. The positive characteristics were that it had feathers instead of skin flaps and a super efficient lung. Since then, birds have evolved into the flightless ostrich (which has relatives to the oldest group of living birds), bucks, geese, and the waterfowl, all within the early Cretaceous period. During the mid-Cretaceous period, woodpeckers, parrots, swifts, owls, passeriformes, and songbirds evolved. In the late Cretaceous period, shorebirds, birds of prey, flamingos, and penguins also evolved.
Summary of Flight
Flight has evolved millions of years ago in all the groups that is capable of flight today. Flight has only evolved a few times in the 500 million years of the vertebrate history and that is an accomplishment. There are four types of ways of flight that have evolved for the vertebrates: parachuting, gliding, flight, soaring. In order to find out how flight has evolved, we first must find out how wings evolved. There was a prediction that wings must have been exaptation by the ancestors for one function. There were hypothesis that showed the wings evolved from arms used to capture small prey, they evolved because of bipedal animals were leaping into the air and it assisted the arms. Another theory was that wings evolved from gliding ancestors who began to flap their gliding structure in order to produce thrust. How flight evolved in a group depends on what its ancestors were doing and the adaptation to them. To understand the evolution of the flying lineage, we must understand the phylogeny of that group, understand the functional morphology relevant to flight, find evidence explaining how flight evolved, and formulate an evolutionary hypothesis why flight evolved in that lineage. The latest sign of flight was when a 130 million year old fossil was digged up by farmers in northeastern China that was evidence of flight which turned out to be a Dromaeosaur. It is a skeleton of a 3 feet long duck-like dinosaur. Scientist believed that the Dromaeosaur and their kin were warmed blooded so t hat there feathers can served originally as insulation, then for display and then for flight. To find these environment where the organisms found also helps to constrain possible behavior. Flight is still a mystery to science today about how it really began and how it is passed on to the vertebrate that are living today. Though vertebrates now mainly evolve flight a few times, the invertebrates has only evolved flight once. The insects were the first animal to evolve flight and is still evolving flight today.
In last week, my group
had study about Vertebrate Flight. It is kind of hard, but it is so cool,
cooler then I never thought about it. Perhaps the most perplexing and controversial
aspect of the study of flight is the study of how and why flight evolved.
Since flight evolved millions of years ago in all the groups which are capable
of flight today. We must know what is flight, base of that, we know about
wings. We can use wings to fly, like birds. In the information that I had,
it told me about the evolution of a flying lineage, and it told me the steps
of it. 1. the phylogeny of that group, what its origins were. 2. the functional
morphology relevant to flight, and how that changed from the nonflying ancestor
to the earliest flyer. 3. accumulate empirical evidence explaining how flight
evolved, using such tools as aerodynamic analyses, ichnology, and paleoenvironmental
assessments. 4. formulate an evolutionary why flight evolved in that lineage,
supported by and consistent with all of the evidence form the previous three
And the information that I found in paper, had a lot about wings evolve. 1. Wings evolved from arms used to capture small prey, the large wing area acted as a net seems rational, but is not support by empirical evidence. 2. Wings evolved because bipedal animals were leaping into the air, large wings assisted leaping. 3. Wings evolved from gliding ancestors who began to flap their gliding structures in order to produce thrust.
Summary on Flight
Flight is an amazing accomplishment, evolved only tree times in the 500 million years of vertebrate history. Flight evolved from the reptiles. Scientists have been arguing about the evolution of flight and according to the fossil records, Archaeopteryx was the earliest bird in the world. It is about 150 million years old. It had teeth and a long reptilian tail, and very few of its bones were fused to each other. These were the feature of dinosaurs. Being compare to the dinosaur, Archaeopteryx had a wishbone and dinosaurs had no wishbone. Unlike the modern day birds, Archaeopteryx had solid bone and modern birds had hollow bone. The solid bone was not good to fly. Archaeopteryx's wing was short and body was large. Modern bird's wing is long and body is small. It is the good feature for flying in the sky. Modern bird's breastbone is larger than the Archaeopteryx's. Ostrich, a largest bird in the world today, cannot fly. Because they have a large body and their wings are short. Its feature looks like some normal birds in the world today. Even though they could not fly, they can run extremely fast so that others animals cannot capture them easily. That's the reason they did not evolve to fly in the sky. And we could see the environment affected the old reptiles to evolve. Wing is the requirement for flight to fly. Wings evolved from arms used to capture small prey. Wing evolved because bipedal animals were leaping into the air, large wing assisted leaping. Wing also evolved from gliding ancestors who began to flap their gliding structures in order to produce thrust. The power for active flight comes from large breast muscles that can make up 30 percent of a bird's total body weight. Later on, the scientist had found a 130 million year-old fossil dug up by farmers in northeastern China that they think it might the ancestor of birds. It was Dromaeosaur, the skeleton of a 3 feet long duck- like dinosaur, a relative of the Velocirator of Jurassic park fame. It was indisputably covered with both feathers and protofeathers, from head to tail. Many scientists believe that Dromaeosaurs and their kin were warm- blooded, so it's good bet that feathers served originally as insulation, then later for display, and still later for flight.
Many birds have their own way of flying. One of its abilities is feather it help to lift the bird so it can fly. Feathers have a lot of flexibility and strength with only a little weight. There are many different kind of feathers one of them is the contour, it covers the whole body and wings of the bird. The contour feathers are asymmetrical and provides aerodynamic. That helps the bird to fly better against wind force he down feather have no hooks and its use is to insulate heat. These type of feathers occur in herons, parrots and hawks. The semi plumes lies beneath the down feathers. It help to insulation and more aerodynamic then the down feather. The filoplunmes are long and have hair like, it have sensory corpuscles to let the bird know where its feather is when its flying. The bristlier have fewer hooks it is mainly found around the eyes and near the mouth. When birds fly the wing muscles have to stretch so it can touch the breast bone. The head of a bird can't b heavy or the weight wont be equal. The bird bones are hollow in the inside so it will be less weight so it is not as heavy.
Mass extinctions have caused drastic changes in the environment. The species that once lived before is now extinct due to the course of evolution. For example, the last dinosaur species died out 65 million years ago, and researchers discovered that species had been dying off since life began when they examined layers of rock. This happened almost four billion years ago, and 98% of the species that once lived are now extinct. It is believed that a large asteroid that hit the Earth caused mass extinctions. The asteroid caused tons of dust to get mixed with the atmosphere and changed the environment so that animals could not live. Although, our side believes that the impact of the asteroid caused the mass extinctions and made it worse.
Mass extinctions have caused drastic changes in the environment. The species that once lived before is now extinct due to the course of evolution. For example, the last dinosaur species died out 65 million years ago, and researchers discovered that species had been dying off since life began when they examined layers of rock. This happened almost four billion years ago, and 98% of the species that once lived are now extinct. It is believed that a large asteroid that hit the Earth caused mass extinctions. The asteroid caused tons of dust to get mixed with the atmosphere and changed the environment so that animals could not live. Another reason why they were caused is due to the earth's climate and volcanic eruptions. However, the volcanoes could not have erupted if it wasn't for the impact of the asteroid when it hit the Earth. When the asteroid hit the Earth, waves of pressures traveled to the other side of the Earth and caused the volcanoes to erupt. At least 5 major episodes of mass extinctions occurred since life developed on Earth. 240 million years ago, 80%-96% of species have disappeared. Marine organisms and species that lived in the ocean died, such as flat shellfish called trilobites and a group of fish called placoderms. Then, two other mass extinctions occurred which marked the end of the Ordovician period about 435 million years ago and in the Devonian period about 360 million years ago. During these times, tens of thousands of marine species have died. Furthermore, another mass extinction occurred during 205 million years ago, ending the Triassic period. Many species of amphibians and reptiles died, and their extinction set the rise of the dinosaurs. And lastly, the end of the mass extinction occurred during the Mesozoic Era 65 million years ago. During this time, dinosaurs, terrestrial species and marine animals died. Their deaths lead to the rise of mammals and marked the beginning of the Cenozoic Era, the era, which we live in today.
During or research on the dinosaurs of our time we found out that there were the last species that died millions years ago. There were rocks that had to be examined by the layer and the researchers found out that the species had been dying since life began which was 4 billon years ago. 98% of the species that once lived are now extinct. The species vanished from natural course of evolution. Many of the ecologists believe that the environment has the main powerhouse of evolution. I agree that the asteroid caused tons of dust that mixed up the atmosphere that change the environment, which also made it hard for them to survive. There were many arguments that were surrounded around extinction and what caused eruption and how it spreaded. Our out come of this was that the extinctions were linked to drastic change of the environment and the asteroid impact etc. The measurements of the different isotopes of gases trapped in the buck ball that revealed unusual ratios of helium and argon. 90% of life's oceans disappeared within a millons years the first vertebrates were the most improvement of the body at the end of the Triassic. The Triassic basically began with mass and extinction and ended with one.
In 65 million years ago, the very last dinosaur had died off. By examining the layers of the rocks, the researched found out that the species had been dying off since life began. Almost 4 billion years ago. The researcher also found out that 98 percent of the species that once lived are now extinct. People think that the species has vanished because of the natural causes of the evolution. Later on, ecologists stated that the environments have been the main "powerhouse" for the evolution. Theories also say that a large asteroid that hit the Earth causes extinctions of dinosaurs. The large asteroid caused tons of dust particles to get mixed with the atmosphere and caused the change in weather. The changes in the environment lead to the large species dying off. There were also other arguments that say extinctions could be also caused by the widespread volcanic eruptions. So now, this could be combination of factors, which had killed off the dinosaurs. Earth's climate could most likely cause for the dinosaurs to go extinct. Scientists are not sure if the extinctions are really caused be the asteroid because fossil evidence shows that the species had already been dying off for thousands of years. When the asteroid hit the Earth, it might not effects the whole Earth but the waves of pressures traveled to the other side of the Earth could cause the volcanic eruptions.
Mass Extinction Meteor caused dinosaur extinction It was like 12.0 earthquake The rock was 12 km across. When it hit the earth, helium from buckyball explore. buckyball has 60 carbon atoms The temperature rose up Fill with carbons Gases cover the skies Dust and aerosols were thrown in the air Sky became dark for months Block out the sun-like a nuclear war
Scientists say that 250 million years ago a comet or asteroid that hit earth is what caused the dinosaur extinction millions of years later. The crash could've set off violent volcanic eruptions that caused land to be covered with hot lava. Gas isotopes were trapped in carbons and eventually carried to earth by a comet or asteroid. 250 million years ago, when Permian period was ending, the tectonic processes of continental drift began splitting pangea apart. Carbon Dioxide made most existing species extinct. Only a few can survive. 185 million years after great dying, dinosaurs extinct 65 million years ago from crash of space object. The impact created a giant chicxulub crater. Cause of dinosaur's death across the globe in trace deposits of iridium, a metal element from outer space.
The extinction of the dinosaurs had always a big question mark to us, because we have limited evidence to prove either one wrong or right. The theory that made the most sense and have gotten the most people to agree on it the meteor-hitting-earth theory. The meteor hit earth and suddenly all the dinosaurs just die off. Personally I think the theory sounds reasonable but then I believe it is not only the meteor that led to the extinction. According to a lot of scientists they think the meteor had trigger other nature reaction. Some of them say it is because of the atmosphere change and led to high CO2 level, and they don't have enough oxygen to breathe. Another say that the dinosaurs die of because they kept on evolving that they are eventually eliminate and become extinct. Animals just automatically update themselves so then this can be a possibly that the environment doesn't suit them no more so then they die oŁ The one I believe the most is that the meteor had hit earth and that it block all the sunlight, the dinosaurs don't have insulation and can't retain heat so they die off' The reason why I believe that is because the famous locality for dinosaurs, Hell Creek is originally a hot place. When a group of animal live in a warm place for a long time they will only have features that can help them stand the heat not the cold. Like the people that live in mountains, they have big lungs so then they can breathe more. The sun is a big light source and it also makes the earth warn, when the earth is not warm no more they can possibly just die off itself.
Dinosaurs are one of the animals that dominated the Earth for 150 million years. Dinosaurs first appear in Triassic period. Scientists believe they were the evolved form of the codants (crocodile-like animal). Scientists believe that the extinction of dinosaurs was because of the chain-reactions of a meteor. They believe that after the meteor hit the Earth, volcano, atmosphere change appear, and because the dinosaurs can't adopt the environment that fast, they died out. Scientists and paleontologists point out that some dinosaur die because of evolution. Scientists predict that if our environment continuous to change, a mass extinction would come soon! The worst extinction in Earth's history - an event 250 million years ago when the vast majority of the living creatures vanished-was cause by the impact of a comet or asteroid much like the one that drove the dinosaurs to extinction millions of years later. The cataclysmic crash must have set off violent volcanic eruptions that covered the land in hot lava, thicken the atmosphere with deadly carbon dioxide and cause rising sea levels to drown the shores of a vast supercontinent.
250 million years ago, the majority of living things vanished. Many say that it was a comet just like how the dinosaurs disappeared but that is just one of the many theories presented. 90 percent of ocean creatures disappeared within a million years and 70 percent of land animals vanished as well. The rock that supposedly hit the earth was 12 kilometers across. Scientists have taken some samples from the certain time period of when the rock hit and found that it is extraterrestrial. They say beside the rock that hit the earth, there was tremendous volcanic eruption occurring at the same time.
Mass Extinction is when a whole group of species die because of some reasons. There are a total of two mass extinctions that ever happened. One of them is the Great Dying; it was when all the marine animals die out. Another one is the dinosaur and also the one we are focusing on right now. The dinosaurs first appear in the Triassic Period, they were first evolve from a crocodile like animal call the codants. In the time of Triassic, the whole was a Pangea so then they can move around easily. They dominated the earth for like about 150 million years. The extinction was 65 million years ago from now. The theory about how they extinct is when the meteor hit then they just vanish. Even though all the scientists came together with a lot of ideas but none of them is really proven right. The meteor hitting earth is clear and we all know that it got to have something to do with the extinction. After doing researching on different resources we came up with the idea of the theory of dinosaurs extinction. They extinct because of the aftermath environment being change.
Evidences show that the meteor is not big enough to wipe out all the living things on earth so then it makes it impossible to believe that the meteor had kill everything. But then after the meteor hit earth, it sent million of dust in the atmosphere and that block up the sun for quite a while. The sun is a very important element for the dinosaurs because they needed heat and food. from Triassic to Cretaceous (when they extinct) the weather is very warm and tropical so then the dinosaurs are born with the mutation of resisting heat instead of retaining it. Also the dinosaur. don't have hair on their body, other mammals needed hair because it help them keep the warmth in their body so then even in the cold weather they still wouldn't be cold Although they have scales, but then it wouldn't keep them warm it is only for protection. Some of the dinosaurs are vegetarians so then when there is no more sunlight the plants can't photosynthesis. Even the strong ones will die off, so then the dinosaurs wouldn't have any more food. For the ones that j are carnivores their food (the dinosaurs that eat plants) dies off also, so even without anything happening they will just die.
Although there are evidence that show an element that is only found outer space is found in a lot of places, knowing that it means that the meteor is spreading out things very efficiently and fast. But even though knowing that wouldn't help that much. That's because the element itself doesn't do any harm. There are no evidences that show the element nor the meteor is carrying anything that's harmful. Closing Statement Although we can't prove our theory is totally right but then a lot of evidences had gave us hints that can prove our theory have a big possibilities- There aren't a lot of things that can prove us wrong. The element wasn't that big of a deal anyhow.
There were five major mass extinction events on the earth. Largest event was about 245 mya ago when continental drift brought all continents together in one whole piece. That caused the climate to change badly. It put and end of Paleozoic era. The oldest event was about 430 mya ago. It put an end of Ordovician period. It caused by an ice age when glaciers covered Africa, then South Pole. Dinosaur extinction occurred about 65 million years ago when the asteroid or comet hit the earth. The rock was about 12 km across. When it hit the earth, it was like a 12.0 earthquake and then changed the atmosphere. The asteroid carried buckyballs, which contained 60 carbon atom structures and helium-3. Scientists believe those gases caused the dinosaur extinction. Another mass extinction happened to the earth ecosystems was the destruction of the rainforest. Another extinction happened in 35 million years ago but its evidence was not clear. Scientists conclude that there are three causes of mass extinctions. First, the sea level changed or fell, reducing size of ocean where most organisms lived, caused extinction. Second, volcanic eruptions released a large amount of carbon dioxide into the air and caused extinction. Third, the sea volume rose up and established floods of anoxia water, caused extinction.
Mass Extinction is believed to have happened millions of years ago, before humans were shown on the face of the earth. About 360 million years ago there were living creatures on earth. Then suddenly a meteor hit the earth. The meteor was believed to have carried a poisons gas, which killed most living things. About 65 million years ago, dinosaurs extinct. Then 250 million years ago 96-percent of all living animals became extinct. 35 million years ago, when there was another mass extinction, we are not clear about what caused it. Researchers believe that another mass extinction can happen to the earth in the future because the Earth's ecosystem, especially Tropical rain forest, are being destroyed due to human activity. Fossil studies show that dinosaurs were wiped out by cataclysme events such as crash of giant meteor that hit the Earth. The extinction of dinosaurs happened extremely fast. Carbon testing was used to determine how old fossils were. Carbon is an essential component to all living organism. Meteorite, are pieces of rock from outer space that strike the Earth's surface. Meteoroids, is a meteorite before it hits the Earth surface, and Meteors are glowing fragments that burns and glows upon hitting the surface of the Earth. Finally, Researchers found out that when meteors hit the Earth, Volcanoes were active, and some even erupted, and killed a lot of animals, and plants. When the dinosaurs died it was during the Mesozoic Period. Asteroids that hit the earth changed the Earths atmosphere killing most living creatures that were around. The ultra violent lights from the explosion killed plankton and changed the environment. When we think of Asteroid's we think of it as a closing chapter in life because when asteroids hit the Earth it wipes out most of the Earths living organisms.
Mass extinctions were events in which species had been wiped off the face of the Earth. They were no longer present and the entire population was gone, never to return again. Within the last 600 million years, there were five mass extinctions. The oldest one was about 430 million years ago at the end of the Ordovician Period, which was caused by an ice age when lots of ice were trapped in the glaciers and caused the sea level to drop more than 100 feet. The shallow seas covering the continents had disappeared which led the animals to become extinct. The largest event happened about 245 million years ago. It occurred when continental drift brought all the continents together in one whole piece, causing climate deterioration. The climate now was changed; seawater froze and the sea level dropped, reducing the size of the ocean where organisms lived. About 65 million years ago, dinosaurs became extinct. No one really knows why but scientists believe that a meteor had hit Earth, causing this mass extinction. Another theory that caused these mass extinctions are this environmental catastrophe that had occurred which wiped out the entire population of species. Also an asteroid led to The Great Dying, in which volcanoes had erupted and most of the animals weren't able to adapt to the new environment so they died. There was another case in which a supemova exploded near Earth, causing deterioration of the ozone layer. Then ultra violent rays killed plankton and mollusks depended on it for food. At some sites, iridium was found in sediment layers at the boundary between the Triassic and the Jurassic period. Iridium is very rare on Earth but common in space objects. A mineral called stishorite was also discovered, where it's not on Earth but a meteorite impact sites. There are still many more theories that scientists haven't explored and hopefully, our questions about events will be answered soon.
In the last 600 million years, there were 5 mass extinctions. The largest event about 245 million years, occurring when continental drift brought all continents together in one whole piece, causing climate deterioration. The oldest is 430 million years end of Ordovician period, caused by an ice age when glaciers covered Africa, then was the South Pole. 185 million years before decrease, mass extinction wiped out 90% of all sea creatures and 70% of land animals. Also extensive volcano activity was present, when hit, was like a 12.0 earthquake. Large extinction rate has an important influence on the evolution of life on earth- the population and repopulation of an ecological niche by species after species allows for the testing of a much wider range of survival strategies than the slower process of phyletic transformation. There are 3 cause of mass extinction. 1) The drop in sea level around much of Pangaea. 2) Volcanic eruptions and release into the atmosphere of large volume of carbon dioxide. 3) Rise sea level, subsequent and floods of anoxia waters.
There had been life on earth as we know it for 4 billion years, during the last 600 million years there has been about five mass extinctions. The most popular extinction was the extinction of the dinosaurs. That happened 200 mya during the Mesozoic era. It is said that a meteor called "buckyballs" about 12 kilometers and made of helium and carbon, collided with the earth changing the environment. This caused volcanic eruptions and changes in sea level. There was also 12.0 earthquakes and vital atmospheric gasses causing much destruction. The collision cause some of the sea water to freeze and dramatically drop, making it hard for many sea creatures to live. The animals that couldn't adapt to the dramatic changes simply, died. Scientist believe in the theory of the meteor because there was an element called Iridium found at most sites. Iridium was rarely found on earth and was mostly found in space objects. Also a mineral called stishorite was found no where else on earth, but at meteor sites. Another mass extinction happened in 245 mya during Continental drift causing climate deterioration. In 430 mya, the ice age kill off many species due to the 100 feet drop in sea level and animals getting trapped in glaciers. There was also said to be a supernova too close to earth that destroyed the ozone layer causing ultra violent rays killing many species. There were also natural cause such as evolving into more complex creatures. These are a few explanations of the mass extinctions.
Summary on Extinction
Extinction took many
lives of organisms on earth. The organisms on earth became extinct about 440
mya. The other group of organisms became extinct about 360 mya. The third
greatest extinction was over plants, in 100 mya.
Pre-Cambrian era was
about 3.500-600 mya. The first fossils was bacteria then origin of O2 by photosynthesis
in 2500 mya. In about 1.500 was the first eukaryotes then diverse to Protists
in 1,000 mya, and multicellular experimentation.
Cambrian period was in
600-500 mya. The origin of all major animals phyla in 500 mya.
The Ordovician period
was about 500-400 mya. The animals were vertebrates and jawless fish in 500-470
mya. The first mass extinction in 420-410 mya.
In Devonian period, bone fishes became abundant in 390 mya. The second mass extinction 360 mya.
Triassic period third
mass extinction in 230-220 mya. Jurassic period fourth mass extinction in
200 mya. Tertiary period fifth mass extinction in 70-60 mya. These extinctions
were caused by land slides, glaciation, and volcanic eruptions.
In Earth's history the five largest mass extinctions have devastated our planet. The first began with the drop in sea level around much of Pangea. This led to a loss of habitat and changes within the weather. Then came volcanic eruptions, which released large volumes of carbon dioxide that also changed the weather. Because of these occurrences it led to one of the largest mass extinction's in the Permian era. The first mass extinction happened about 440 million years ago in the Ordovician period. When this occurred the first early vertebrates were starting to evolve with jawless fishes, and animal diversity too. The second mass extinction happened within the Devonian period about 360 million years ago. By this time bony fished became abundant. Then when the fourth hit 200 million years ago during the Jurassic period it whiped out almost the entire species of dinosaurs. Then the fifth mass extinction took place during the Tertiary period between 70-60 million years ago. These were the five mass extinctions that happened within the Precambrian era. These mass extinctions led to many questions of how and why did they happen. Until this day it is still being debated on. One theory was glaciations, which caused rapid warming, and severe climatic changes. Another theory that paleontologists believe in is volcanic eruptions. They believe that these volcanic eruptions sent large loads of sulphates into the atmosphere causing large ash clouds around the world. Unfortunately these are only theories to help explain the causes of these events.
Helen: Good head start but you can also talk about the buckybalt hitting on earth and exploded and so on. Wardah: Nice start but include evidenc Jing: detail the evidence. good job on starting Maria: has the right information but you can get more than just that. Pei: Good details, you also can get more information for the internet.
As the other side pointed out that volcanoes causes the dinosaurs to become extinct. Then why are there no new evidence claiming that every time when a volcano erupts, species will go extinct. What I am trying to say is that if a volcano is able to cause a whole entire species to extinct, then if another volcano eruption occurs than would it mean that another species would become extinct. As our side pointed out it was the meteor that causes the dinosaur to become extinct. When the meteor hit Earth, the little dust particle on the meteor broke off and spread throughout Earth, and the dust particle causes the atmosphere and climate to change. More rain began to fall and the weather became colder. It got too cold that the dinosaur simply just froze to death. I will leave you guys one question to think about, hwy are people so afraid of a meteor hitting Earth?
Summary on Mass Extinction
Since Earth was here about 4.6 billion years ago, there had been five mass
extinction that had occurred. Mass extinction is when an event that caused
a large portion of organism on earth to became extinct. Before all those mass
extinction happened, in the Precambrian era 3,500-600 million years ago there
was an early fossil that show bacteria, and origin of oxygen by photosynthesis.
There is also eukaryotes that is diverse protests that is multicellular. In
the Cambrian period around 600-500 mya there is origin of all major animal
phyla. In the Ordovician period around 500-400 mya there was animal that is
diverse abounds and a lot of early vertebrates and jawless fish.
The first Mass Extinction happened 440 mya during the Silurian period where
the plants, arthropods, and fungi invaded land and jawed fishes appeared.
The second one is 360 mya during the Devonian period where bony fishes become
abundant. The third one happened in 230-220 mya in the Permian period-Triassic
period. The fourth one happened in the Jurassic period around 200 mya and
the fifth one happened in the Tertiary period between 70-60 mya.
During the Permian period around 268-258 mya a buckyballs survived the trip
to Earth inside a giant asteroid or comet that exploded and killed all the
dinosaurs, it was more forceful than the largest earthquake about 185 mya.
About 90% sea creatures and 70% land animals died. The species that is bigger
than a dog like fusulinid Foraminiferas, trilobites, rugose, tabulate corals,
blastoids, acanthodians, placoderms, and pelycosaurs did not survived. Only
the smaller one survived like crocodiles, lizards, turtles, and snakes this
made bird and mammals the dominant on land. Before 250 mya you could walk
from Madagascar to anywhere in the world because the planet's landmasses were
united in the super continent Pangaea. But as time went by it would slowly
change which caused the Mass Extinction.
Some causes in the Permian period were that there was a global widespread
cooling and worldwide lowering of sea level. Another cause is that the reduction
of shallows continental shelves due to the formation of the continent Pangaea,
which made it easier for extinction. But this did not happen until the late
Permian. Another cause is that in the north and south poles that the rapid
warming and serene climatic fluctuations produced by concurrent glaciation.
There is also evident that show some cooling and drying in the temperature
zone which cause the dune sands and evaporates while the polar zones, glaciation
was prominent. The last cause is that volcanic eruption which made a quantity
of sulfates and an explosive that made a large ash clouds around the world.
This combination made a lower global climatic condition.
Extinction is portions of organisms on earth became extinct about 440 million years age. Around 250 million years ago, at the end of the Permian period, life on the earth almost disappeared completely in the most devastating mass extinction of all time. The first began with the drop in sea level around much of Pangea, which led to a loss of habitat, climatic instability and the elimination of many narrowly distributed species. As the oceanic regression continued, phase two began, with volcanic eruption and the release into the atmosphere of large volumes of carbon dioxide, which increased climatic instability and facilitated ecological collapse. The rise in sea level and subsequent floods of possibly anoxic waters destroyed near-shore terrestrial habitats. After other mass extinction, life began biological communities were so severely disrupted. The few remaining species tended to be abundant and widespread, with clams thriving in the ocean and a retile-like creature the most common vertebrate on land. About 25 million years later, other organisms began to emerge, with more mobile creatures dominating in the sea, and a shift in insect, from those with wings fixed in flight position, to those that could fold their wings. Before the dinosaurs went extinct, an even greater catastrophe killed 70 percent of land creature and 90 percent of sea life. Now scientists studying sediment from that time, 250 million years snuffing out the trilobites, sea corals, and most other living things.
Mass Extinction Over million years ago around the years of 286-248 it was Permian period time. The Terristrial faunal diversification happened in the Permian and about 90 or 95 percent of species became extinction was one of the well known one in earth history. Some terristrial victims such as the fusulinid foranifera, trilobites, rugose and tabulate corals, blastoids, acanthodians, placoderms, and pelycosaurs, which didn't survive in the boundary of Permian. The reason why Permian Extinction might of occured was because of the Formation in Pangea, glaciation and of volcanic eruption. Although the formation Pange, the reduction in oceanic continental shelves, and so many destruction happened. In the evidence of Glaciation made a big impact by strange weather schedule and the view of evidence of volcanic actions suggests that maybe huge amounts of volcanic were large in quantity of sulphates into the atmosphere and large clouds of ash. The extinct went by pretty fast though. Another theory that scientists made were that maybe a big asteroid hit the planet while the dinosaurs used to live there. Maybe a food chain connection had somethinfg to do with the extinction of dinosaurs, who knows its a mystery!
Summary on Mass extinction
Before extinction of human there was dinosaurs and many other organisms that was wiped out throughout some period of time, which is consider mass extinction. For example dinosaurs can be consider a mass extinction because dinosaur eventually became extinct. Large portions of organisms on earth became extinct about 440 million years ago (mya). Then another one about 360 million years ago and the third extinction was about 100 million years ago yet the greatest extinction literally devastated over planet. About 250 million years ago majority of the creatures was vanished caused by the impact of a comet or asteroid similar to the extinction of the dinosaurs. Within the comet or asteroid contain buckyballs, which survived its trip on earth causing a great explosion and killed the creatures. The dinosaurs' extinction was about 185 years ago million years ago during the cretaceous period. One of the biggest extinction was the Permian period, which was 286-248 million years ago. During the Permian period it caused 90-95% of marine species to become extinct in the Permian. It was the largest mass extinction ever and the theory to explain the extinction was the reduction of shallow continental shelves due to the super-continent Pangaea, result in environmental struggle for space. Another reason would be glaciations event outcome a rapid warming and severe climatic fluctuations, which was made by concurrent glaciation events on the north and south poles. There is evidence showing cooling and drying shown by thick sequences of dune sands and evaporates while in the polar zones. Next was the final suggestion was the last on that paleontologist had was volcanic eruptions, it was large and sent an amount of sulfates into the atmosphere. The explosive which mite have caused and produced large ash clouds around the world outcome that it may have lower the global climatic conditions. During the cataclysmic crash that might have set off violent volcanic eruptions that covered the land in hot lave, thickened the atmosphere filled with deadly carbon dioxide and caused sea levels to rise and down the shored of a vast super continent. As a result 90 percent of life in oceans disappeared and at least 70 percent of the vertebrate land animals disappeared, which scientist called it "The Great Dying." The first mass extinction was 440 million years ago, the Silurian period (between 400-440 mya) had some plants, arthropods, and fungi invaded lands and jawed fishes to appear. During the second mass extinction, Devonian period (400-360 mya) and bony fishes to be abundant. Third mass extinction, the Permian period (between 230-220), fourth mass extinction, Jurassic period, 200 mya, and 5th, the Tertiary period, between 70-60 mya. Overall, mass extinction had affected many creatures to extinct in our world.
Mass extinction is an episode during which large numbers of species become extinct. There were few extinctions happened before the dinosaurs extinct. Before land exists, there was no land. Every organism lived in the seas or ocean. Even before apes exist, there were few extinction happened already. Mass extinctions have a major impact. The first extinction was about 440 million years ago, a large portion of organisms extinct. Then about 360 million years ago, almost the same thing happened. Then a hundred million years later, the extinction was greater then the other ones, about 96 percent of the animals extinct. Around 35 million years later, extinction happened on earth. The last extinction was about 65 million years ago, that included the dinosaurs.
The reason why the dinosaurs were extinct is the buckybalts survived trip to earth inside a giant asteroid or the comet that explored and killed them. The large catastrophe killed 70 percent of the land creatures and 90 percent of the sea animal. The primary marine animals included blastoids, rugose, placoderms, tabulate corals, etc. During the Permian period, ninety to ninety-five percent of marine species became extinct. This was the largest extinction even happened. There were many theories explain the reason of the extinction. There were speculated causes of the extinction, some said it was by a global widespread cooling that lower the sea level, and the formation of Pangea, and the glaciations, and maybe the volcano eruption.
Us humans are members of the older primates, along with the apes, monkeys, and prosimians. The early mammals evolved into primates and humans evolved from non-human primates. As evolution affects the human line, you can see that the first humans became bipedal, the formation of their skeletons were changing, spinal cord extended, and brains got bigger therefore they were becoming more smarter. Human evolution goes far back in time, and scientists are still trying to get it together on how far back does the lineage really goes and what the exact lineage really is. Primates such as chimpanzees and gorillas lived about eight to ten million years ago, while early humans such as Australopithecus that found to have lived in Africa are about four to two million years old. Scientists said that humanity's earliest known ancestor lived in East Africa about six million years ago. It was said that the human's earliest known ancestors belongs to the genus Australopithecus. Australopithecines and humans are classified as hominids. The oldest species was called Australopithecus afarensis which was known to be 3.9 million years old. In 1994 another discovery was made. The pre-human fossil, Ardipithecus ramidus, was then the oldest known at that time (4.4 million years). On January 2001, an older fossil was found by a French team in Kenya. The fossil was named Orrorin tugenensis and it was nicknamed as the "Millennium Man," it was found to be 6 million years old. The only problem with this fossil is that the whole possibility of Orrorin tugenensis as being the earliest hominid was questioned by a scientist on whether that it could possibly be "a common ancestor, or it gave rise only to the chimpanzee lineage, or it went extinct around 6 million years ago without giving rise to any species." Anyhow, based on the book Biology. Principles & Explorations, by Johnson and Raven, "We are the third and only surviving species of humans, members of the genus Homo. The first humans evolved from australopithecine ancestors about 2 million years ago. They were replaced in turn by a second species of human that moved out of Africa and spread across the Earth.
The evolution of hominids started around 80 million year ago during the age of dinosaurs. Scientist believes that we Homo sapiens had evolved from primates. Australopithecine has two characteristics that were early clue on the path of leading to the evolution of humans. They were able to walk upright on two legs. The first africanus skull what found by an anatomy called Raymond Dart. They skull was very well preserved. Before Raymond Dark found the first australopithecine fossil many Scientists believe hominids were only around 500,000 years old. But now they believe that they are 2.8 million years old. Afarensis is really human like and apes like, so there is a evolutionary link between human and apes. Many were believe evolution of Homo sapiens did evolve from apes. Then later evident were found, they found another species called robustus which leads closer to Homo sapiens. Then they found the third species called boisei, which it has been the mostly likely to Homo sapiens. Scientist believes that boisei was around 2 million years old. Scientist always wonders how old is man? Then Donald Johanson went to search for early human fossils, then he found Lucy, one of the first preserved skeleton of a prehuman hominid ever discovered. The skeleton was believed 3.2million years old. Was our early human really 3.2 years old? No it is not, The UC Berkeley anthropologist has discovered the fossilized remains of what they believe in humanity's earliest known ancestor. They believe that it walked the wooded highlands of East Africa. They fossils was 6 million years old, which they believe is the oldest ancestor of Humans.
Tyrone: good job
Cherry: Very nice... you have a lot of info and evidence right there. Well, I don't see nothing wrong so yeah...
David: very nice argument a have lots of evident, argument more more more!!!!!!
We are traying to prove that the hominids came from Africa and -t#att ' . Our theory is that the Hominids first originated from Africa and that then they spread through out other places. We have search a lot of information and we have found that most of the ape fossils that they have found were in Africa and they also have been the oldest. h et of the fossils that they have found have been discover in many parts of Africa some were found in Ethiopia and they were 1 million years old, another one was found in Kenya it was 6 million years old and it was a kid. Something else is tha a 1.5 to 2million years old Hominid fossils was found in Africa. Some of the Homo sapiens spread from Africa 150,000 and 100,000 years ago, that is why they have found fossils in other places because they had spread from Africa many years ago. Some of the fossils that they have found in other places besides Africa were not that old, so our theory is right for us, sense they have found the oldest and the most fossils in Africa.
The primate evolution began about 80 Million years ago during the age of the dinosaurs. Some of the first primates evolve 6o million years ago. Their have been many fossils found in many places from different places. Some fossils show the age they show that 38 million years ago prosimians, which means (before ape) were common found in North America, Europe, Asia and Africa. Few prosimians have survive today which are little monkey's that have the head as the size of a house cat. One of the best fossils that they found was Lucy a 25 year old adult female, 40 percent of her body was found and their they study more on how their body was almost the same as ours. The fossils evidence show that humans evolve from the evolutionary line that gave "rise to apes." Apes evolve from the old world prosimian's ancestors apes included Giddons, Orangutans, Gorillas, Chimpanzees, and bonobos. The first Erectus was discovered in 1891, By Dutch Physician near the village of Trinic on a island. When they first evolve they had two changes, it was that they develop with grasping fingers and toes and also the position of the eyes in the primates. The skull were particular vanabie as evidence for the evolution of the Hominid brain. The mans that study about how our body evolve also discover that our DNA is almost similar to some of the apes so that shows a lot of informational. They have also found that many parts of the apes body is similar to ours, the shape of our head has been the same from different apes and also the bone structure the only differences is that our head is a little bigger. Some of the first apes had the smallest brain and heads. The bones in the body were almost the same two, one of the differences is that wild they were evolving they were walking straighter. some of the first apes use to walk with their nucleus but as they were evolving they started walking more straight, they also started evolving in their way of life and the were evolving their way of thinking.
There has been many theory about human evolution and how we are here today. Some people with no scientific intelligence say that we hatched from an egg and some people with more intelligence say we evolved from a ape or a gorilla. Through current studies, we can say that they are the closest to being right because human and many apes have similar DMA structures. Also, fossil evidence shows that evolutionary like "diornal", gave "rise to apes". Hominids evolved into regional variants that are sometimes treated as different species: There are two changes that occurred during human evolution: the development of grasping limbs, and the position of the eyes in the primate. During the evolution of hominids, there have been different classifications of hominids, Australopithecus (5,000,000 -1,000,000 BC), Homo Habilis (2,200,000 1,600,000 BC), Homo Erectus (1,600,000- 500,000 BC), Home Saipiens (500,000 80,000 BC), Homo Neanderthalensis (100,000 - 33,000 BC), and Homo Saipiens Sapiens (125,000 - Today). A 40% fossil of a 25 years old Australopithecus named Lucy was found. In 1891, the first fossil of a Homo Erectus was discovered. It was found by a Dutch physician named Eugene Dubois, near the village of Trinicon, the island of Java. A new fossil was found in Indonesia. The skull's feature has both the feature of a Homo Sapien and a Homo Erectus. It was named "Madeliene" and it had a capacity for a language close to modern humans. Human skulls are valuable because it can help determine the evolution of the Hominid's brain. Basically human fossil remains are very precious. Especially complete skeletons because they are so rare and hard to find.
The first Primate evolved 60mya, but the first Primate evolution began in the 80 (mya) during the age of the dinosaurs. Most of the fossils were found in Africa and Asia but never North America or South America. Scientist could tell that how ape's evolved by reading their DNA, then Scientist compared DNA from a human and an ape, which were similar. Hominids however are remained really precious, because complete skeletons are extraordinary rare. Hominids Evolved into regional variants that are sometimes treated as different species. Skulls were particularly valuable as evidence for the evolution of the Hominid brain. New fossils were found in Indonesia, the fossil's skull has both features of a Homo Sapiens & Homo Erectus. "Madeline" had a capacity for language close to that of modern humans. A partial face was found in Atapuerca in Spain, it was believed to die between the ages 10-11.5 years old. The fossil was about 780,000 years old. A famous skeleton had to be Lucy a 25yr old female. About 40% of her skeleton was found. Dutch Physician discovered 1 1st Homo erectus in 1891. Eugene Dubois near the village of Trinilon the island of Java. From the time that gave "Rise To Apes" apes evolved from old world Prosimian ancestors about 30million years ago, modern apes including Gibbons, Orangutans, Gorillas, Chimpanzees and Bonbons. A Homo erectus fossil name Nanjing was found in China.
Hominids Fossil, the most important about the evolution of the humans, but it was so difficult to find a complete fossil, because it's so easy to broken, also some of the part are already lost or disappear by the corrosion. We can find this kind of the fossil in the Asia, America and Spain. Why did the fossil important for human? Because it tell us to know when did the beginning of the human, and how was their trait, it was so important to figure out the mystery part of the human's evolution.
The first primate evolution began about 80 MYA, which was after the age of the dinosaur; the first primate is about 60 MYA. When that time, they have two changes, the fist time was they developed the finger and toes; the second one was their eye's position became like the human. After that, we find the fossil about 38 MYA, which was the prosimian, the word that means, "ape" in English. We can find it in North America, Europe, Asia and Africa.
In 36 MYA, the primates became revolution, and it change to be "diurnal" ape, and they became like human, active at day and slept at night. When this time fossils, we just find it only in Africa and Asia. After that, the Ape became evolution to many animals like Gibbons, gorillas and chimpanzees. The biologist believes that human are changes by monkey because the DNA of the human and Ape are similar. They can use the animals DNA to figure out which animals was the youngest to change human, which one was the oldest one.
We can learn that everything was converting by simple cell, so I have an idea about the human evolution. Sometimes people saw someone face like the ape, because their DNA has some of the Ape, so they look like the monkey. But the most important thing was: Did the human are the last evolution of Hominids? No really, because time was changing, the DNA of the human body also cans evolution. May be many years later, The human will be the history, and the human will evolution to be a higher creature in the Earth.
Human beings were considered as the most intelligent and complex animals on Earth. That is because our ability to use language, our behavior, and our unique characteristics are matched by no other species. Scientists have been arguing about the age of human existence, and according to fossil records, the oldest fossil found is called Australopithecus, which was nearly 3.2 million years old. There were also other fossils found that proves how human has evolved and how long we existed, such as the Mungo Man Skeleton, Homoerectus, etc.
Scientists have been studying about how human has evolved into our current form, and argued about our evolution through many centuries. However, there are evidences that shows we were evolved from apes, or animals looked similar to monkeys. As an important part to our evolution, our hip has taken an important place. At first our ancestors have smaller hips than what we have now, and they were unable to stand up straight and unable to do different movements comparing to us today. As we evolves, our hips have developed larger and was able to support our upper body weight and letting us to stand straight and move about more freely.
Fossils were found to prove our age of existence, and act as proves for our evolution. Homoerctus, fossil that existed for 1 million years and disappeared 500,000 years ago. Mungo Man Skeleton, skeleton fossils that has an age of between 15,000 to 60,000 years old, and according the lab studies, these fossils have proved that our most recent ancestor lived 200,000 years ago in Africa. Besides from human body structure fossils, there are also brain structure that even existed before the evolution of human beings. According to fossil record, the first brain structure appeared in reptiles around 500 million years ago. The functions of this hindbrain included breathing, heart beat regulation, balance, basic motor movements, and foraging skills. Evolution is a process of acquiring more and more sophisticated structures, not simply the addition of different structures. Therefore, the modern human brain contains the hindbrain region, often called the protereptilin brain, and it is the seat of fundamental homeostatic functions. The major structures found in this region of the brain are the Pons and Medulla.
Although we were still unsure about how long we human have existed, but scientists continued their research and were finding new information every day in order to answer unsolved questions about hominids. Human beings are continuing to evolve nowadays and so is our intelligence, also that another reason which proved us humans as the most complex animals on Earth is due to our intelligence and our senses of thoughts.
Hominid refers to members of the family of humans. It consists of all species on our side of the last common ancestor of humans and living apes. The split between humans and living apes used to be thought to have occurred 15 to 20 million years ago.
There are many species of hominid. Our earliest ancestors belong to the genus Australopithecus. There were two characteristics that leaded to the evolution of human. One is that they were bipedal. This means that they were able to walk upright on two legs. The other characteristic of the Australopithecus was that they had large brains with a greater volume, relative to body weight, then apes had.
Another genus in hominid is Homo. The fist member of our genus is the Homo habilis. It has a skull with a volume of about 640 cubic centimeters. Because they use tools they were name Homo habilis. Homo means man and habilis means handy. Homo habilis was short, around 1.2 meter tall and lived in Africa for 500,000 years and then was extinct and replaced by a new species of human with an even larger brain. The next species that evolved was the Homo erectus. Many specimens have been found, and they all indicate that Homo erectus was distinctly human. Some of the men known as Java man and Peking man are recognized as Homo erectus. The skull of Homo erectus had prominent brow ridges like modem humas. They have smaller teeth and a less protruding face than Australopithicus and Homo habilis.
We belong to the species Homo sapians sapians. Modern forms of Homo sapians sapiens first appeared about 120,000 years ago. Modern humans have an average brain size of about 1350 cubic centimeter and we still exist today.
When they talk about Homo sapiens they believe that they came from the same family as chimps and primates. Many people believe in the theory that humans came from a common ancestor as the chimps and primates but many people also do not. Scientists have found to believe that our most recent ancestor lived in Africa 200,000 years ago. The Australopithecus is the oldest found ancestor and it was 3.2 million years old. Human's ability to use language makes us the most advanced species on Earth. The first sight of a brain was found in a reptile. Their brain regulated heartbeat and temperature and simple things like that. The brain then went under some dramatic changes and became the human brain, which has advanced things like sexual, emotional, and fighting behaviors. People believe evolution to be the adaptation to a species environments and surroundings. The Cro-Magnon's, which arrived in Europe 40 thousand years ago brought behaviors that were similar to humans. These Cro-Magnon had common human practices like burial, painting, burial, and understanding of materials. Humans looked nothing like the Levant anatomically. The humans looked more like the Levantine Neanderthals anatomically. The Homo neanderthalensis had the same size brain as Homo sapiens but a different shaped skull. Scientists believe that there were more than just neural changes in the brain to the current species. Scientists believe that between 60 and 50 thousand years ago there was an event that happened that improved the human brain to become the way it is now. They have only found that the time period doesn't fit the event that could have happened. Homo neanderthalensis had a mastery of the natural world. People believed that since the neanderthalensis made such beautiful stone tools they did have some kind of verbal communication. Japanese researchers did an experiment in which they separated two groups and let one group use non verbal skills and the other use verbal skills to make the same kind of tools. They came to believe that the Neanderthals had no kind of verbal communication. Scientists have proven that natural selection cannot create anything and does not propel anything into existence. They believed that neural change happened genetically and not by adaptation to anything. On a Japanese island scientists conducted an experiment which they gave children fruits. Soon the fruits became to be covered by beach grit and the children eventually learned to wash them. The adults took a longer time to catch on to this and this is why scientists believed that language and the neural change started with children. They believed that the neanderthal had to small of a pharynx to speak and that the humans longer pharynx allowed it to speak giving it an advantage. The scientists also believe that you need a brain to speak because the brain tells the vocal tract what to do.