Table of Contents
What is a change in the size or frequency of a trait based on competition for mates?
Ch. 15 Evolution TEST Review
| Question | Answer |
|---|---|
| Change in size or frequency of a trait based on competition for mates | Sexual selection |
| One species will sometimes diversity in a relatively short time into a number of different species | Adaptive radiation |
| Idea that evolution occurred in small steps over millions of years | Gradualism |
What is evolutionary change?
Evolution is defined as the change in the inherited traits of a population of organisms through successive generations. When particular genetic sequences change in a population (e.g., via mutation) and these changes are inherited across successive generations, this is the stuff of evolution.
How does the frequency of traits change in a species over time?
Microevolution reflects changes in DNA sequences and allele frequencies within a species over time. These changes may be due to mutations, which can introduce new alleles into a population. Eventually, genetic drift can cause a subpopulation to become genetically distinct from its original population.
What is an example of stabilizing selection?
Stabilizing selection in evolution is a type of natural selection that favors the average individuals in a population. Classic examples of traits that resulted from stabilizing selection include human birth weight, number of offspring, camouflage coat color, and cactus spine density.
How does natural selection change the frequency of traits?
From one generation to the next, the struggle for resources (what Darwin called the “struggle for existence”) will favor individuals with some variations over others and thereby change the frequency of traits within the population. This process is natural selection.
How is the frequency of an allele affected by evolution?
In population genetic terms, evolution is defined as a change in the frequency of an allele in a population. Using the ABO system as an example, the frequency of one of the alleles, IA, is the number of copies of that allele divided by all the copies of the ABO gene in the population.
Which is statement correctly describes the role of chance in evolution?
(Remember the equation for a population in Hardy-Weinberg equilibrium: p2 + 2pq + q2 = 1.) Allele frequencies in a gene pool may shift randomly and by chance. What is this random shift called? Which statement correctly describes the role of chance in evolution?
How did Mutation lead to increased genetic variation?
Mutation led to increased genetic variation. Over time, humans have steadily increased their movements across the continents of the Earth. Which of the following results has most likely been derived from these movements?