Download S7L5a Evolution Study Guide Answer Key

S7L5a. Evolution Study Guide Answer Key
1. Who was Charles Darwin? Where and when did he travel? Charles Darwin was a
biologist who studied changes in organisms over time. He traveled on the HMS Beagle
from 1831-1836 and traveled all over the world, but some of his most important
discoveries were in the Galapagos Islands.
2. What important work did Darwin write? On the Origin of Species
3. What two animals did Darwin study? What differences did he notice and what did he
think were the causes of these changes? Finches: beak size, differences in food sources.
Galapagos Tortoises: shell shape, different predators or food and water sources.
4. What is evolution? The process in which organisms change over time.
5. What is natural selection? What do people mean when they say “survival of the fittest?”
Natural selection is a natural process resulting in the survival of organisms best
adapted to the environment. A process whereby those best equipped for the conditions
in which they are found survive and pass their genetic material on to the next
generation. As animal populations grew and resources became scarce, this condition
created a struggle for existence, the outcome of which was that only the “fittest”
survived.
6. Describe Kettlewell’s experiments. Kettlewell studied peppered moths in the 1950s. He
captured both forms of the moth (light and dark) and raised them in captivity. He
released some of them into an area with light trees and some into an area with dark
trees. He later captured and counted the moths, and found that dark moths were more
likely to survive in dark forests, and light moths were more likely to survive in light
forests.
7. Describe this branching diagram (organisms that are more closely related than others)
Colobus monkeys are more closely related to baboons than orangutans or owl monkeys. Owl
monkeys are more closely related to spider monkeys than chimpanzees. Gorillas are more
closely related to orangutans than spider monkeys.
8. When a population is challenged by an environmental change, where most organisms die
but a few survive, what might be different in the new population that grows? The trait
that prevented them from dying the first time will become more prevalent in the new
population.
9. Can we “see” natural selection in action? Why or why not? Natural selection occurs over
so many generations, it would be impossible to see changes occur at any given moment.
10. Draw a graph for the following data.