Speciation

Question 1

Adaptive radiation

Answer 1

The evolutionary diversification of a number of related species to occupy newly available and different niches

Question 2

Allopatric speciation

Answer 2

Occurs when two populations become geographically isolated (also reproductive isolation) leads to speciation

Question 3

Allopatric species

Answer 3

Two closely related species geographically isolated from each other

Question 4

Allopolyploidy

Answer 4

The process where 2 different species produce and infertile hybrid. Germinal cell chromosome doubling can lead to instant new species

Question 5

Analogous structures

Answer 5

Structures in unrelated species that have the same function but have evolved differently. They do not share a common ancestor.

Question 6

Autopolyploidy

Answer 6

Homologous chromosomes do not separate during meiosis leading to a diploid number of chromosomes present in the gametes.

Question 7

Biogeography

Answer 7

A branch of biology that investigates the geographical distribution of plants and animals

Question 8

Cline

Answer 8

A measurable gradient in a single biological trait of a species across a geographical range

Question 9

Co-evolution

Answer 9

Changes in one species leads to reciprocal changes in another. They evolve together as they exert selection pressures on each other.

Question 10

Convergence

Answer 10

Unrelated species evolve superficially similar characteristics under similar environmental selection pressures

Question 11

Deme

Answer 11

A subset of a population where there is limited gene flow with members of the larger populations

Question 12

Divergence

Answer 12

A population of a species diverges into 2 or more descendent species resulting in once similar species becoming increasingly dissimilar

Question 13

Founder effect

Answer 13

A small number of individuals emigrate from a population and establish a new population with reduced genetic diversity

Question 14

Gene flow

Answer 14

The transfer of genes and their alleles from one population to another

Question 15

Gene pool

Answer 15

The total genetic information of an interbreeding population

Question 16

Genetic drift

Answer 16

The process of change in genetic composition of a population due to chance or random events rather than by natural selection

Question 17

Genetic variation

Answer 17

The differences in genetic material between individuals within a population

Question 18

Geographic isolation

Answer 18

Populations are separated by geological features such as deserts, rivers, mountains ranges etc.

Question 19

Gradualism

Answer 19

The hypothesis that evolution occurs by the accumulation of very small changes that occur at a regular rate over long periods of time

Question 20

Homologous structures

Answer 20

Structures that have a similar evolutionary history but have developed to provide different functions

Question 21

Hybridisation

Answer 21

The process of an animal or plant producing offspring with an individual of another species or variety

Question 22

Macroevolution

Answer 22

Evolution above the species level especially with regard to the evolution of whole taxonomic groups over long periods of time

Question 23

Microevolution

Answer 23

A change in allele frequency within a population usually brought about by natural selection over short periods of time

Question 24

Natural selection

Answer 24

The process whereby organisms better adapt to their environment tend to survive and produce more offspring

Question 25

Nondisjunction

Answer 25

Occurs when homologous chromosomes do not separate during meiosis

Question 26

Polyploidy

Answer 26

where an organism have more than two homologous sets of chromosomes in their somatic cells (>2n)

Question 27

Population bottleneck

Answer 27

A sharp reduction in the size of a population due to a chance event usually catastrophic

Question 28

Post-zygotic isolating mechanism

Answer 28

An isolating mechanism that occurs after the zygote has formed

Question 29

Pre-zygotic isolating mechanism

Answer 29

An isolating mechanism that occurs before the zygote has formed preventing the organsim from being produced at all (prevents sexual reproduction)

Question 30

Punctuated equilibrium

Answer 30

The hypothesis that evolution occurs with periods of stasis punctuated by rapid changes due to sudden changes in selection pressures

Question 31

Reproductive isolation

Answer 31

A barrier exists that prevents organisms of different species mating and producing fertile offspring - prevents successful interbreeding

Question 32

Sexual isolation

Answer 32

A type of natural selection where members of one sex choose mates of the other sex to mate with based on preferred phenotypic features

Question 33

Speciation

Answer 33

The formation of a new species from an existing species

Question 34

Species

Answer 34

A group of organisms that interbreed under natural conditions and are reproductively isolated from other species

Question 35

Sub-species

Answer 35

A taxonomic rank below species. Subspecies cannot be separated from the species group as successful interbreeding can take place

Question 36

Sympatric speciation

Answer 36

The origin of a new species without geographic isolation from the ancestral species

Question 37

Sympatric species

Answer 37

Species that have previously diverged from a common ancestor now existing in the same area but continuing to remaining reproductively isolated.

Question 38

Vestigial structures

Answer 38

An unused feature that is a historical remnant of a structure that served a purpose in the organism’s ancestor.