what darwin never knew video

Same genes responsible for different beaks

Depends on intensity and timing of when gene is turned on Body plan genes- switches that control genes that make proteins

•Embryos look extremely similar upon conception

Different animals look same and use same set of key genes to build bodies Body position, patterning Number of genes doesn't matter, but how they're used

Explaining finches

Different beaks must be helping finches survive Use beaks as tools

Language, music, math

Different by 18 letter in humans and 1 letter between chimps and chickens

Sequence all of human DNA and other animals

Do complex animals have more genes than simpler ones? Humans have 23,000 genes Same as chicken, less than corn Many key genes identical to other animals

• Modern science can look to DNA

Double helix made of 4 AGTC Found in every living cell on earth DNA is code that contains info to make living things grow and develop Forms genes Translated into proteins Proteins make stuff of bodies

• Single species gives rise to many

• Fish give rise to all mammals

Descent with modification

Fascinated with dog breeds Dog breeders can create new forms by breeding Whippet= terrier+ greyhound Same type of breeding and selection happened in nature without human interference

about Darwin

Father made him go to med school due to being Too squeamish Father sent him to study for clergy;Here he revived childhood interest in nature he then Gained reputation as naturalist

Neil Shubin Must be transitional form- part fish with beginnings of legs

Found fish with flat snout and upward staring eyes Pushed head out of water using arms Named Tiktalik •Perfect transitional form •Covered in scales and had arm-like fin •Bone structure seen in limbs of other mammals

Argentina

Found fossils of giant mammals

One type of male has spots and dances before sex, others are plain and don't dance Paintbrush gene codes for spots on wings Both plain and spotted have gene Dark matter of genome- 98% that doesn't code for proteins

Found mysterious stretch of DNA only found in spotted fly and put in unspotted fly Wings now glow in the dark and have spots • Gene turned on in fly • Piece of DNA called switch- turn on and off genes that make proteins

Snakes have bumps where legs used to be in ancestors

Front flippers of whale has bones like fingers and remnants of pelvis Must have ancestor that came from land

• Manatee and whales lost limbs to be more streamline

How? Ocean stickle-back has fins on belly like spikes • For defense • Harder to eat Lake stickle-backs lost spikes

Dude at Yale found 13 genes not present in chimps

Inserted gene with blue stain in mice embryos Spread all over body especially in thumb and big toe Human brain 3x bigger than chimps and structured differently

Paddlefish is relative of Tiktalik •Paddlefish is more primitive form than Tiktalik •Should share same genes •Shubin looked at paddlefish embryos Hox genes- found in all complex animals Critical to shape and form of animal

Key role in formation of paddlefish fins •Cartilage that grow out from torso •Same genes create long upper arm bone in humans and paddlefish •2 forearm bones also found in mammals •Sequence that also makes digits •Tiktalik found lots of food on land

o What is needed to grow brain?

Locate genome that controls when brain is big enough etc. Found gene that directs brain growth • Gene in humans different from one in chimps due to mutations

• Arizona desert has patches of light sand and dark volcanic rock

Originally all mice had light fur for camouflage 2 groups of mice exist now Light fur mice that live on sand Dark fur mice that live on rock

On the Origin of Species

People no longer thought species were perfect Provided scientific theory based on facts and observation Knew there were holes in theory •Didn't know how it worked •What happens inside body that makes it change?

• Birds he collected were 13 species of finch Looked different based on what island they lived on Originally there must have been 1 kind of finch that diversified into differ kinds with different beak shapes

Same with tortoises and shells Prevailing view was that God created every creature perfectly Little sloths and armadillos found in Galapagos that varied from fossils he found Must be ancestors that transformed

Darwin thought nature was savage in competition for survival

Saw pattern that creatures that survived were the ones best adapted to environment Others were perfect killing machines or good at camouflage

Scientists found spike gene in both ocean and lake stickle-back • Think answer lies in switch • Mutations in lake stickle-back meant switch was broken and spike gene couldn't' be turned on

Scientists found lines on abdomen bigger on left, smaller on right • Clue of where hind limbs used to be • Looked for same switch in manatee and sickle-back

Great advances in evolution Look for places where human is different from chimp but chimp is almost identical to other animals

Differences weren't in actual genes but found in switches More than half nearby gene by brain Cortex- wrinkly outer layer of brain

Studied developing embryos

Whales had teeth has embryos, disappeared before birth • Descendant of creatures with teeth Humans have slits like gills that become bones of inner ear • Shows humans descended from fish • Developed into gills in fish

Galapagos Islands

600 miles off Ecuador in Pacific Ocean Penguins, giant tortoises, marine iguanas Can tell what island tortoise is from based on shell (clue) Collected birds, especially finches

•Tiny variations make difference between life and death Environment selects who lives and who dies

After many generations, fit get fitter and unfit vanish Variations accumulate and different species branch off Evolution by Natural Selection

Doesn't stay the same Get ½ DNA from mom and ½ from dad Creates brand new combinations

Also changes through mutations Generates variation Can happen as DNA copies itself and cells divide Mutations passed to children cause big changes Genes in mice described above are exactly the same except one

Only species to punish, create art, music, architecture, science, medicine, etc. Darwin suggested humans descended from apes

Annoyed church "humans created in image and likeness of God" Chimp and human DNA 99% identical Ability to touch each finger with thumb Extreme precision

o Muscular dystrophy- mutation in gene that robs muscles of ability to repair themselves

Another dude found a muscle-making gene with 2 letters missing •Should cause disease •Also found in apes Found in muscle used for chewing Humans chew with fraction of force of apes

•Skulls of apes and humans made of independent bone plates Muscles for chewing pull against these plate

Apes have huge jaw muscles Forces apes skull plates to fuse together earlier so brain can't grow Human skulls expand into adulthood creating bigger space for brain

Variation- not every individual is same

• Variation is starting point for change

•All life forms are related Creatures that started out exactly the same evolved to look completely different

•Birds from dinosaurs •Mammals from fish

•Short, powerful beak- hard seeds •Small, probing beak- Narrow spaces for nectar

•Different food source= different beak •Beaks alter to fit diet of island How finches transform into many