Evolutionary Analysis

Question 1

adaptation

Answer 1

A trait that increases the ability of an individual to survive or reproduce compared with individuals without the trait.

Question 2

adaptive radiation

Answer 2

The divergence of a clade into populations adapted to many different ecological niches.

Question 3

adaptive trait

Answer 3

A trait that increases the fitness of its bearer.

Question 4

additive effect

Answer 4

The contribution an allele makes to the phenotype that is independent of the identity of the other alleles at the same or different loci.

Question 5

additive genetic variation

Answer 5

Differences among individuals in a population that are due to the additive effects of genes.

Question 6

agent of selection

Answer 6

Any factor that causes individuals with certain phenotypes to have, on average, higher fitness than individuals with other phenotypes.

Question 7

alleles

Answer 7

Variant forms of a gene, or variant nucleotide sequences at a particular locus.

Question 8

allopatric model

Answer 8

The hypothesis that speciation occurs when populations become geographically isolated and diverge because selection and drift act on them independently.

Question 9

allopatry

Answer 9

Living in different geographic areas.

Question 10

allozymes

Answer 10

Distinct forms of an enzyme, encoded by different alleles at the same locus.

Question 11

altruism

Answer 11

Behavior that decreases the fitness of the actor and increases the fitness of the recipient.

Question 12

anagenesis

Answer 12

Descent with modification but no speciation.

Question 13

ancestral

Answer 13

Describes a trait that was possessed by the common ancestor of the species on a branch of an evolutionary tree.

Question 14

antibiotic

Answer 14

A chemical, typically extracted from a microorganism, that kills bacteria by disrupting a particular biochemical process.

Question 15

antigenic site

Answer 15

A portion of a protein that is recognized by the immune system and initiates a response.

Question 16

assortative mating

Answer 16

Occurs when individuals tend to mate with other individuals with the same genotype or phenotype.

Question 17

average excess

Answer 17

The average excess for allele a is the difference between the mean fitness of individuals carrying allele a and the mean fitness of the entire population. If the average excess for an allele is positive, then the allele will rise in frequency.

Question 18

back mutation

Answer 18

A mutation that reverses the effect of a previous mutation; typically a mutation that restores function after a loss-of-function mutation.

Question 19

background extinction

Answer 19

Extinctions that are not part of mass extinction events; thought to be due to typical types and rates of environmental change or species interactions as opposed to the extraordinary environmental changes that occur during mass extinctions.

Question 20

Bateman gradient

Answer 20

The slope of the best-fit line relating reproductive success to mating success. Measures the strength of sexual selection.

Question 21

Bayesian Markov Chain Monte Carlo

Answer 21

An approach to phylogeny inference based on computing the probability that a particular tree is correct, given a specific model of evolution for the characters being analyzed and the data observed.