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Biology
Chapter 2.3 pg. 113
Name ___KEY______
Evolution by Natural Selection
1. Differences among species are the result of . . . Changes across time
2. What is the source of variation?
genetics
3. How can humans bring about change in a population of organisms?
Selective breeding (example, horses, Kale and plants)
4. What is a species?
A group of organisms whose members very closely resemble each other because they share many key
characteristics.
5. What would happen according to Mayr if all individuals born reproduced successfully?
The population size would increase exponentially.
6. According to Mayr are any two individuals exactly the same? Why does he think this?
No two are exactly the same because they display an enormous variety of characteristics.
7. What did Thomas Malthus believe about the relationship to humans and our resources?
Humans continually will grow to over populate the available resources
8. Which organisms are most likely to reproduce in an environment of struggle?
The organism that is best equipped to survive
9. What are adaptations?
Beneficial traits that are inherited
10. What are the adaptations for the snake caterpillar, flicker and red Irish lord fish?
Looks like a snake, sharp beak for helping get food, blends in with surroundings
11. How do the above mentioned adaptations benefit the organism?
Protect from predators, Camouflage, easier to get food
12. What is the difference between selective breeding and natural selection?
The change is caused by the organism’s ability to meet the challenges of survival and reproduction in
a natural setting
13. How does competition affect natural selection?
Organisms need to compete for food/nutrients while coping with it’s environment
14. How does predation affect natural selection?
The predator prey relationship can determine if the prey has the opportunity to reproduce or not or if
the predator has enough to eat
15. Do individual organism or populations evolve?
Populations!
16. What does “descent by modification” mean?
Common ancestors for different species because of adaptation/modification
17. The theory of evolution explains the origin of diversity and the relationships among modern
species and their ancestors.