- All phenotypic variation between individuals is due only to environmental factors.
Which of the following observations led to Darwin's major inferences?
- Members of a population vary in their heritable traits.
- Body parts that are not used deteriorate over time.
- Although organisms can produce huge numbers of offspring, many of these offspring do not survive.
- The first and fourth answers are correct.
A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10% are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population?
Which of these conditions should completely prevent the occurrence of evolution in a population over time?
-The environment is changing at a relatively slow rate.
-All phenotypic variation between individuals is due only to environmental factors.
-The population lives in a habitat where there are no competing species present.
-The population size is large.