Evolution and Natural Selection

1. Evolution and Natural Selection

2. TRUE • Natural selection is not all-powerful; it does not produce perfection • If your genes are “good enough,” you’ll get some offspring into the next generation—you don’t have to be perfect Natural Selection does not produce perfection, just “good enough”.

3. TRUE • Natural selection is a process rather than a guiding hand • Natural selection is the simple result of variation, differential reproduction, and heredity • It is mindless and mechanistic. It has no goals; it’s not striving to produce “progress” or a balanced ecosystem. Natural Selection has no goals; it’s not striving to produce “progress” or a balanced ecosystem

4. FALSE • The genetic variation that occurs in a population because of mutation is random • Selection acts on that variation in a very non-random way: genetic variants that aid survival and reproduction are much more likely to become common than variants that don't Natural Selection is a random process

5. TRUE AND FALSE • Chance and randomness do factor into evolution • Important mechanisms of evolution are non-random and these make the overall process non-random --- selection • Process of mutation, which generates genetic variation, is random, but selection is non-random Evolutionary theory implies that life evolved (and continues to evolve) randomly, or by chance

6. FALSE • Natural selection doesresult in the evolution of improved abilities to survive and reproduce • Mutation, migration, and genetic drift may cause populations to evolve in ways that are actually harmful overall or make them less suitable for their environments • Evolution produces a tree, not a ladder Evolution results in progress; organisms are always getting better through evolution

7. FALSE • Populations, not individual organisms, evolve • Evolutionary change is based on changes in the genetic makeup of populations over time Individual organisms can evolve during a single lifespan

8. TRUE AND FALSE • Evolution occurs slowly and gradually, but it can also occur rapidly • Over the past 50 years, we've observed squirrels evolve new breeding times in response to climate change, a fish species evolve resistance to toxins dumped into the Hudson River, and a host of microbes evolve resistance to new drugs we've developed Evolution only occurs slowly and gradually

9. FALSE • Humans often cause major changes in the environment, we are frequently the instigators of evolution in other organisms. • Pesticide and bacterial resistence Because evolution is slow, humans cannot influence it

10. FALSE • Genetic drift has a larger effect on small populations, but the process occurs in all populations • Genetic drift occurs because, due to chance, the individuals that reproduce may not exactly represent the genetic makeup of the whole population • In large populations, the changes in gene frequency from generation to generation tend to be small, while in smaller populations, those shifts may be much larger Genetic drift only occurs in small populations