Key Terms for Exam 1

Question 1

Any change in the inherited traits of a population that occurs from one generation to the next (over a period longer than the lifetime of an individual in the population)

Answer 1

Biological evolution

Question 2

A process by which populations of organisms change over time

Answer 2

Evolution

Question 3

A chain of ancestors and their descendants.
May be the successive generations of organisms in a single population, the members of an entire species during an interval of geological time, or a group of related species descending from a common ancestor

Answer 3

Lineage

Question 4

A mechanism that can lead to evolution, whereby differential survival or reproduction of individuals causes some genetic types to replace (outcompete) others

Answer 4

Natural selection

Question 5

The independent origin of similar traits in separate lineages

Answer 5

Convergent evolution

Question 6

Characteristics are similar in two or more species because they are inherited from a common ancestor

Answer 6

Homologous

Question 7

A derived form of a trait that is shared by a group of related species (i.e., one that evolved in the immediate common ancestor of the group and was inherited by all its descendants).

Answer 7

Synapomorphy

Question 8

A visual representation of the evolutionary history of populations, genes or species

Answer 8

Phylogeny

Question 9

Any change to the genomic sequence of an organism

Answer 9

Mutation

Question 10

Occurs when genetic material from different strains get mixed into new combinations within a single individual

Answer 10

Viral reassortment

Question 11

Evolution arising from random changes in the genetic composition of a population from one generation to the next

Answer 11

Genetic drift

Question 12

A protein on the surface of the influenza virus that latches it to a host cell

Answer 12

Hemagglutinin

Question 13

Measurable aspects of organisms, such as morphology (structure), physiology, and behavior. Genes interact with other genes and with the environment

Answer 13

Phenotypes

Question 14

A group of organisms that a taxonomist judges to be a taxonomic unit, such as a species or order

Answer 14

Taxon (taxa)

Question 15

The science of describing, naming, and classifying species of living or fossil organisms

Answer 15

Taxonomy

Question 16

The study of layering in rock

Answer 16

Stratigraphy

Question 17

The study of prehistoric life

Answer 17

Paleontology

Question 18

The permanent loss of a population or species, arising with the death or failure to breed of the last individual

Answer 18

Extinction

Question 19

The idea that the natural laws observable around us now are also responsible for events in the past.

Answer 19

Uniformitarianism

Question 20

Traits are similar because they are inherited from a common ancestor

Answer 20

Homologous

Question 21

Traits are similar because they have converged on a shared form. Not derived from a common ancestor

Answer 21

Analogous

Question 22

A mechanism that can lead to evolution, whereby differential reproduction of individuals causes some genetic types to replace (outcompete) others

Answer 22

Natural selection

Question 23

Inherited aspects of an individual that allow it to outcompete other members of a population that lack the trait (or that have slightly different version of the trait).

Answer 23

Adaptations

Question 24

Arises when individuals of one sex (usually males) compete with each other over access to individuals of the other sex. It can lead to the evolution of traits like showy ornaments or weapons that improve an individual’s chances of mating

Answer 24

Sexual selection

Question 25

A change in the frequency of traits or genetic variants that arises across generations due to random events. Most pronounced in small populations

Answer 25

Genetic drift

Question 26

Terminal ends of an evolutionary tree, representing species, molecules, or populations being compared

Answer 26

Tips

Question 27

Lineages evolving through time between successive speciation events

Answer 27

Branches

Question 28

A point in a phylogeny where a lineage splits (a speciation event)

Answer 28

Node

Question 29

Nodes within a phylogeny representing ancestral populations or species

Answer 29

Internal nodes

Question 30

An organism and all of its descendants

Answer 30

Clade

Question 31

A term used to describe a group of organisms that form a clade

Answer 31

Monophyletic

Question 32

Heritable aspects of organisms that can be compared across taxa

Answer 32

Characters

Question 33

Phylogenetic methods that construct trees by grouping taxa into nested hierarchies (clades) according to their shared derived characters (synapomorphies)

Answer 33

Cladistics

Question 34

Character state similarity not due to shared descent (ex. produced by convergent evolution or evolutionary reversal)

Answer 34

Homoplasy

Question 35

The reversion of a derived character state to its ancestral state

Answer 35

Evolutionary reversal

Question 36

A trait that originates performing one function, and which is later co-opted for a new function

Answer 36

Exaptation

Question 37

Members of the hominin genus Australopithecus

Answer 37

Australopithecines

Question 38

Similar to natural selection, except that it results from human activity. When breeders nonrandomly choose individuals with economically favorable traits to use as breeding stock, they impose strong _____ on those traits.

Answer 38

Artificial selection

Question 39

The transfer of alleles from one population to another. Occurs when organisms or their gametes move from one location to another

Answer 39

Gene flow

Question 40

Structures constructed by organisms that can influence their performance or success. Although they are not part of the organism itself, their properties nevertheless reflect the genotype of each individual. Animal examples include the nests constructed by birds and the galls of flies.

Answer 40

Extended phenotypes

Question 41

An antipredator strategy used by a potential prey item to signal danger or a lack of palatability. Ex. warning coloration

Answer 41

Aposematism

Question 42

The physical proximity of alleles at different loci. Genetic loci that are physically close to one another on the same chromosome are less likely to be separated by recombination during meiosis, and are thus said to be....

Answer 42

Genetic linkage (genetically linked)

Question 43

Strong selection can "sweep" a favorable allele to fixation within a population so fast that there is little opportunity for recombination.

Answer 43

Selective sweep