Chapter 12. Chapter 12: Evolution and Extinction

What factors other than natural selection influence...?

Interactive Study Guide

false

true

Guiding Question 12.2

What factors other than natural selection influence the evolution of a population?

Why You Should Care

Genetic drift and its variations, the bottleneck and founder effects, are all ways that the proportion of genes in a population may randomly change. You should care about this because the genetic diseases that typify different ethnic groups came to be prominent in those communities through random accumulation of genes in the population. Many ethnic groups have accumulated genetic disorders that are rare in the general population but common enough within their populations that couples are encouraged to get genetic counseling before starting a family.

Question Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term	Definition
+ISbhKosHhxnAmI6PFU0QD689dQBmReobfcYo4eO+S/sJLekHBDXQLXTg7qvyela1r8Q5GaJtnI=	When a small group with only a subset of the larger population’s genetic diversity becomes isolated and it evolves into a different population, missing some of the traits of the original.
mlGp+MFcu9NnrOjLVQqZXA0ecSRLjXKskmUeG4hID9KKO6Z82jiKvv33Fc1DMBE7c9ZwfznEdNM=	The change in gene frequencies of a population over time due to random mating that results in the loss of some gene variants.
WGdPqA2ozlESreWla1m+k5sEZrrHmsSofj3/TxesFCAZdIo3ejqkZrYwQF0Obuz/T1rqiAMbySI=	When population size is drastically reduced, leading to the loss of some genetic variants, and resulting in a less diverse population.

999

Try again.

Correct.

Incorrect.

Question 12.1

All of the following scenarios depict populations that have lost genetic variation. Determine whether the following scenarios are depicting genetic drift, the bottleneck effect, or the founder effect.

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

999

Try again.

Because the seals’ numbers were greatly reduced but they weren’t randomly accumulating changes or moving to a new territories, this is an example of the bottleneck effect.