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sloth
Stickleback fish
Tree of life: map out 6 variations of a species
What Darwin Never Knew: Nova Video http://video.pbs.org/video/1372073556/
 What was Darwin’s Theory of Evolution?
 What was the one thing Darwin was missing to finalize his theory of evolution? DNA
 Darwin became quite well known as a Naturalist and was offered a position on the HMS
Beagle to survey the waters around South America.
 Where did Darwin make his first important discovery? Argentina
 The Galapagos Islands: 13 isolated islands in the Pacific Ocean and home to penguins,
tortuous and marina iguanas,
 Tortus shells differed based on which island they came from
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Darwin was fascinated with birds and collected a variety of species.
Why would there be slightly different species on different islands?
Snakes have leg bumps that are present as embroyos
Humans have slits in embryo stage, but develop into the bones in our inner ear compared to
fish. This gene codes for gills.
What does it mean, “Nature is a battlefield”?
Finches had different beak shapes
Tools as beaks. They evolved to fit their environment
Looking different=variation, the starting point for change in nature
Evolution by natural selection: the fit get fitter, the variations that are not as adaptable, die
150 years later his ideas are still respected as ture
Dark mice live on dark rocks and light fur live on the light rocks
DNA holds the code to answering the question of how did this happen?
What is so amazing about DNA: only 4 letters make all of the creatures on this planet
Mutation generates variation within a species
Mutations are not only bad, it depends on the environment that the species is living in.
To understand how evolution works, all you have to do is compare a creatures genes. This
would explain the variation and why it was developed.
23,000 genes in humans (The human genome project)
Many of our key genes are identical to many other animals
What else contributes to evolution? The embryo is the platform for diversity based on the
genes. All living creatures are made from the same 4 nucleotide bases (A,C,T,G)
It’s not the number of genes that you have that matter, it’s how they are sequenced
Junk: The dark matter on the genome. 98% does not code for anything. 2 % is what actually
make up our phenotype (visible characteristics).
Switches are very powerful in DNA and can be turned on and off when needed.
Switching genes on is now explaining how some adaptation have occurred. How a snake
loses its legs. Snakes must have evolved from some type of creature with legs (reptile)
Sticklebacks have lost their spikes on their belly and are now called Lake Sticklebacks. Why
was the gene turned off and not code for spikes? Maybe there are not the threat of predators
now that it is living in the lake instead of the ocean.
50 minute mark in the video (Stop and do an activity of time lines)
 Finch Beaks:How much you turn on the gene, when to turn in, how long it is turned on and
where it’s located
 Tree of life: map out 6 variations of a species
 Pattlefishis (Ticktalic fish) one of our only surviving fossil relative. They live in the
Mississippi River
 Humans are the only species who think about what others think about us, to perform art and
to have the knowledge to destroy it all.
 Today, it is accepted that we are descendent from apes. Our DNA is 99% similar.
 One of the most unique structures in the human body is our thumb
 Human brain is 3 times larger than a chimpanzee
 Muscular Dystrophy: The genes responsible repairing muscle is turned off
 Missing two nucleotide bases on the gene that codes for the muscles for chewing determines
strength of jaw muscle
 A human’s skull is open up to the age of 30 while a chimps brain fuses by about 3 years old
to accommodate the huge muscle that powers their jaw.
 Last 10 minutes is Human Genome
 One piece of DNA stands out to be the most important in the human genome, the cortex. The
human cortex is extremely different compared to all other organisms