Extra Credit Notes - Peterson PDF

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Peterson...

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documentary Knew) Evolution document ary (What Darwin Never Kne w) *Charles Darwin’s theory: published The Origin of Species 2+ million species

Charles Darwin *ancient fish ancestor to all four limbed species - poor student, sent away to medical school - set out on 5-year voyage  

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Discovered fossils in Argentina o Fossils were ancestors of smaller creatures that were still living Galapagos Islands o Found penguins, tortoises, iguanas o All creatures adapted to new environment, warm climate, life in land/water o Darwin sat and rode on tortoise shell o Tortoise shells varied depending on Galapagos island they lived on o Collected birds (believed they were finches, all like one species)  Species varied by islands Collected animals/plants o Realized species change, one original finch species then adapted o 1 tortoise= several species with new shells

DECENT MODIFICATION 

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o Why? o Dog breeders selected for traits, does this occur in nature? Embryos o Learned whales had teeth as embryos o snakes had legs as embryos o Humans had gills as embryos Species survived based on best adaptions to environment o Finches (Galapagos Islands)  On island with hard seeds = short hard beak  Flowers = thin pointing  Beaks changed to fit diet available on island Variation [starting point for change] o Mice in desert  Lived on light rock (camo) when living on dark rock easy for predators to identify; adapted to live with dark fur  Mutations causes variation in DNA 23,000 genes in humans (like chickens and some plants)

Gene Switch     

Paintbrush gene in fruit fly determines spots and glowing in the dark on wings Snake evolved from 4-legged animal Whale flippers has arm bones (finger bones) Bone switches in manatees, whales, snakes Finches are born with full size beak, gene switches occurring in the embryo

Tectalik -

Structure of a 4-limb animal (tectalick) o Flat head fish o Why did it have this change?  Believes the arm-like fins dragged itself onto land o Hox genes  Determines form of body

Humans o o

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Similar ape DNA 13 places where DNA was different  Injected the DNA into a mouse embryo  Coded for thumb and big toe Brain is 3x bigger than chimps Muscle DNA error, missing 2 genes  Protein is for jaw muscles, apes uses more power in jaw to chew  Apes jaws fuse causes less brain growth In humans, disease causes brain to grow to less than half normal size; in apes there is different gene mutation...