Speciation Key Terms

Question 1

Adaptive Radiation

Answer 1

A form of divergent evolution characterised by the rapid evolution of a number of different species from a single common ancestor.

Question 2

Allele Frequency

Answer 2

The proportion of a particular allele in the gene pool compared to all other alleles for the same gene/locus.

Question 3

Allopatric Speciation

Answer 3

Speciation that occurs when the populations are in different geographic locations.

Question 4

Allopolyploidy

Answer 4

Polyploidy resulting from the hybridisation of genomes from different species.

Question 5

Analogous Structures

Answer 5

Features which have different evolutionary origins but have similar functions, and may have similar appearances.

Question 6

Aneuploidy

Answer 6

The state of having an abnormal number of chromosomes in a cell.

Question 7

Autopolyploidy

Answer 7

Polyploidy involving genome multiplication arising within a single species.

Question 8

Bottleneck Effect

Answer 8

The change in allele frequencies due to a sudden reduction in population size.

Question 9

Co-evolution

Answer 9

The type of evolution where the evolutionary changes in one species act as a selection pressure on another, and vice versa.

Question 10

Convergent Evolution

Answer 10

The process by which unrelated species evolve to resemble one another.

Question 11

Directional Selection

Answer 11

A mode of selection characterised by selection for one end of the phenotypic range, shifting the whole disruption in one direction.

Question 12

Disruptive Selection

Answer 12

A mode of selection charactarised by selection for the extreme phenotypes and selection against the normal phenotype.

Question 13

Divergent Evolution

Answer 13

The process by which two or more species are formed from a common ancestor.

Question 14

Evolution

Answer 14

The change in the gene pool of a population over time.

Question 15

Gene Pool

Answer 15

The total set of alleles that are present within a population.

Question 16

Genetic Drift

Answer 16

The change in allele frequencies due to random sampling and chance.

Question 17

Gradualism

Answer 17

The process by which speciation occurs at a slow yet constant rate, with accumulation of continuous small changes over long periods of time resulting in gradual transitions from one species to another.

Question 18

Homologous Structures

Answer 18

Features which are similar in structure and origin but have different functions.

Question 19

Migration

Answer 19

The movement of individuals from one population to another.

Question 20

Polyploidy

Answer 20

The state of having more than two sets of chromosomes.

Question 21

Post-zygotic RIMs

Answer 21

Reproductive isolating mechanisms which prevent gene flow by acting after the egg has been fertilised.

Question 22

Pre-zygotic RIMs

Answer 22

Reproductive isolating mechanisms which prevent gene flow by acting before the egg is fertilised.

Question 23

Punctuated Equilibrium

Answer 23

Speciation characterised by long periods of little or no change followed by a sudden burst of rapid speciation.

Question 24

Reproductive Isolating Mechanism

Answer 24

Any factors which prevent individuals from different populations from breeding.

Question 25

Speciation

Answer 25

The evolutionary process where populations evolve and become distinct species.

Question 26

Species

Answer 26

A group of related organisms which can breed and produce fertile offspring.

Question 27

Stabilising Selection

Answer 27

A mode of selection characterised by selection for the average phenotype and selection against the extreme phenotypes.

Question 28

Sympatric Speciation

Answer 28

Speciation that occurs when the populations are in the same geographic location.