Your inner fish vidoe that you will need to watch PDF

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Your inner fish vidoe that you will need to watch but i gotchu...

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Your inner The host of this show, Niel Shubin is a paleontologist, anatomist and developmental biologist.He hunts for Fish fossils in theCanadian arctic.When asked "what kind of Doctor are you, Neil Shubin replied i am a fish paleontologist . Fish are the first creatures with bony skeletons. The Tree of Life.Around 400 million years ago you'll find fish swimming in oceans and streams.40 million years later the first Amphibians appear on land. Then you see reptiles followed by mammals around 200 mya.Every reptile, bird and mammal alive today is descended from ancient fish . Basic Pattern of Limbs.Here's a dog.Dogs run and jump.What do you have?____1____ bone, ____2_____ bones,little bones, and then the digits . Same pattern in birds!Charles Darwin:"The reason why animals have this common pattern is because that at some time in the distant past they all shared a common, ancesstors.To find fossils.There is a checklist we run through.We look for places in the world that have rocks that are the right age ........Then you look for places in the world that have rocks that are the right type .The kinds of rocks that are likely to hold fossils.Ventastega, Acanthostega, Ichthyostega, Hynerpeton(found in Devonian rocks) (circle the three species referred to as "The 'Stegas'")Some of the best specimens have been found in greenland ...We had a narrow window in the month of july when the snow melts just enough to let you in.The approximate age of the Devonian rocks in Shubin's search are is: 375 million years.In both fish and people what you find are a series of swellingscalled gale arches .In fish those swellings become components of the gill apparatus In humans they become portions of our lower jaw, portions of our middle ear and portions of our voicebox.An advantage of descended testicles is better temperature control A disadvantage is: hernias We are, every one of us, just a jury rigged fish .Embryological interlude.Chick embryos. Fruit flies. Might a single molecule,that comes from a single gene,signal the development of limbs?embryological interlude Sonic hedgehog a single gene(name), was the source of the signal responsible for generating the pattern of the digits.If we turn down sonic hedgehog fewer fingers are made but if we were to increase the effect of sonic hedgehog we would get extra fingers.These very basic patterning mechanisms are performing the exact same functions in the skate, the shark,

in the chicken, in the mouse all the way up to Humans .Back to Greenland, July 2004.The local Inuit people named our fossil Tiktaalik which means Large Freshwater Fish.Here was an animal Darwin predicted!Skeletal Features we have in common with Tiktaalik are: 1 bone, 2 bone . lots bone pattern, neck wrist , limbs and elbow.And what information-containing molecule links us back to Tiktaalik? DNaAClass DiscussionWhy is it important (or interesting) to find transitional fossils?What are the different lines of evidence that point to a shared ancestry among ourselvesand other vertebrates? Invertebrates?What processes (evolutionary, developmental, other) result in the changes in animal form over evolutionary time?...