What Darwin Never Knew
How many genes do humans possess?
23,000 genes
How long was the voyage of the HMS beagle?
5 years (It was supposed to be 3 years)
What is the human genome project?
A scientific research project that tries to find the base pairs that make up human DNA
What discovery did Darwin make about the finches?
All of the birds he collected were a variation of a single bird. Meaning that species change. (Birds on the Galapagos had 13 types of finches. But they looked different depending on the island it came from.)
Why did Darwin use artificial selection to explain natural selection?
Because like natural selection, artificial selection uses the best traits possible for survival
What is the problem with the view of nature that shows "lions lying with lambs?"
Because nature is savage and every creature is for itself, It's not realistic, the lion would eat the lamb
Why is there so much diversity of life on earth?
Because of evolution, species adapt and change; natural selection that makes new species
How is the pocket mouse an example of natural selection?
Because their only chance for survival us it's camouflage and if they don't adapt to their environment, they will die
Why are fruit flies, Drosophila, good studies to study?
Because they are small, cheap and reproduce quickly
Why do embryos start out so similar and end up so different?
Because they start out with the same set of key genes to build their bodies and then they diversify later on
What is the best way to compare creatures?
By their genes
Describe DNA, how it is used, and how it changes.
DNA is made of a long molecule, spiraling around a double helix us made out of 4 smaller molecules G, A, T, and C. Found in cells of every living thing on Earth. Contains all the information to make living things grow and develop. Makes dimples, hair, and other things. Changes in reproduction and mutation when mutation occurs in the cells we pass down to our offspring, they can cause a big change
Describe the fossils Darwin found.
Dug up skulls, jaws, and backbones that turned out to be giant mammals (giant armadillos and sloths) and this made him wonder what their relation was with the live animals
What was the standard view about why animals were different at the time?
God had created ever species and what he made was perfect and couldn't change
What happened when Charles went to Cambridge?
He didn't succeed but found his calling for nature. He learned many things and becomes a solid field scientist.
What did Darwin do instead of going to school?
He was offered a place on the HMS beagle
What happened to Charles when he was sent to Edinburgh?
He was squeamish and didn't like operations. He saw a child being operated on (and this was in the era before anesthetics) and vowed to never return
What didn't Darwin know about?
How evolution took place (the physical forces that change the way species appear) and DNA
Explain Darwin's idea with the tree of life.
If you go far back enough humans come to fish and bird come back to dinosaurs so animals that don't look remotely alike are deeply connected. Beginning with a common ancestor over time across generation species could change dramatically. Some add new body pieces while other lose them. This is a process called a descent with modernification
How do we get variation? Think about our study of genetics?
In any generation, the animal is in a litter are never quite the same, in the wild, such a tiny variation might make the difference between life and death. Two penguins for instance, might differ a tiny bit in the thickness of the blubber, a big factor if you live in extreme cold. In a harsh climate, the environment will select who will live and who will die. These tiny variations would allow the fit to get fitter and the unfit to vanish.
How did the population of mice change colors?
In genetic mutations, all the mice genes are identical until one gene separates
What is Tiktaalik? How does it help explain evolution?
It's a 375 million year old fossil of a fish with land fins. Tiktaalik is a perfect transitional form. Much of its body is that of a fish. It's covered in scales. But it also had something very un-fishlike, an arm-like fin, or, perhaps, a fin-like arm. Tiktaalik had the bone structure that is seen in the arms and legs of every-four limbed animal: one big bone at the top; two bones underneath, leading to a cluster of bones in the wrist and ankle
What is Archaeopteryx? How does it help explain evolution?
It's the oldest known fossil bird, of the late Jurassic period. It had feathers, wings, and hollow bones like a bird, but teeth, a bony tail, and legs like a small coelurosaur dinosaur. It helps support evolution because it's in the transitional form between dinosaur and bird
Describe the animals Darwin saw on the Galapagos Islands.
Marine Iguanas: He described them as hideous creatures with a dirty black color, sluggish movements, and were black as the rocks they crawled on. Giant tortoises: weighed up to 600 lbs, moved 4 miles a days, shells are different based on the island it came from (Dome like shells and saddle like shells and had different colors) Finches: had different beaks depending on which island it came from Penguins that swam above the equator
When did Darwin publish his book (Origin of Species)?
November 24th, 1859 (Finished sailing in 1836)
What is the "wrong statement" about the pocket mouse changing colors?
Pocket mice change just for natural selection
What discovery did Darwin make about embryos?
Snake embryos had tiny legs but would never develop in adult snakes. Therefore they were descents from an animals with legs. Whales have teeth as embryos but not as an adult whale, so they were a descent from an animal with teeth. Human embryos had gils but not in adult humans so humans were descents from fish
What 2 books did Darwin write?
The Origin of Species by means of natural selection and The Common Descent of Man
What is the lopsided pattern? How does it explain evolution?
The lake stickleback has the traces of the bones from the spikes. And they are lopsided, bigger on the left than the right. It explains evolution because it shows the animal's body evolved to meet it's climate
What is a stickleback? How does it explain evolution?
The ocean stickleback has a pair of fins on its belly that are like spikes, while the lake stickleback doesn't. It explains evolution because the lake stickleback evolved to meet it's new habitat
What are switches in DNA? What do they explain?
They aren't genes. They don't make stuff like hair or muscle, but the turn on and off the genes that do. They allow animals to use genes on one place and not another
What is evolution by natural selection?
This is when an animal evolves in order to survive. An example is the finches of the galapagos island. Their beaks vary depending on which island they live on, since there are different resources. Some beaks are short and strong because they have to eat tough seeds and others have long and small beaks so they can get pollen. Their beaks alter to fit the food of each island and that's how one finch changed to many. When variations accumulate and eventually new species branch off.
What was the reason for the voyage of the HMS beagle?
To survey the waters around South America
What is artificial selection?
When humans breed animals and plants for specific traits