Speciation: Fill in the Blanks

Evolution: change in __ frequencies.

allele

Species: a group of organisms which can naturally __ to produce fertile offspring.

interbreed

Speciation: the formation of __ species from a common ancestor.

new

Population: a group of members of the same species, in the same __ at the same time.

location

Deme: a population which has little or no __ flow with other populations of the same species.

gene

Cline: a species spread across a geographic range which display a gradual change in a __ characteristic.

phenotypic

Ring species: a species which is spread around the globe latitudinally, which displays a gradual change in a phenotypic __.

characteristic

Punctuated equilibrium: a model of evolution with long periods of little or no evolutionary change - known as __ - which are punctuated by short periods of relatively rapid bursts of evolution.

stasis

Gradualism: slow, constant rate of change within a species over time in response to changes in __ pressures.

selection

Divergent evolution: speciation where two or more __ species are formed from one common ancestor species.

new

Adaptive radiation: speciation where one common ancestor splits into multiple __ species.

new

Convergent evolution: two unrelated species face similar selection pressures so evolve similar __ characteristics.

phenotypic

Parallel evolution: two related species evolve similar characteristics despite no gene flow and physical __.

separation

Coevolution: two species, linked by a biotic relationship, evolve __ of each other as the one species acts as a selection pressure for the other species.

reciprocally

Homologous structures: similar in __ but may be different in function, evidence of divergent evolution from a common ancestor.

structure

Analogous structures: different in structure but similar in __, evidence of convergent evolution.

function

Vestigial organs: a structure that has been __ or lost function, providing evidence of a common ancestor.

reduced

Genome: the complete set of __ of an organism, including all genes.

DNA

mtDNA: mitochondrial DNA, the only DNA found outside of the __.

nucleus

nDNA: DNA found in the __.

nucleus

Gene flow: the transfer of genes and __ between members of a species through reproduction.

alleles

Ploidy: the number of __ in a cell.

chromosomes

Euploidy: complete sets of __; eg, n, 2n, 3n, 4n…

chromosomes

Eupolyploidy: at least on extra complete set of chromosomes due to complete non-disjunction in __ of meiosis.

anaphase

Aneuploidy: an abnormal number of chromosomes in a cell due to __ of a chromosome or chromatid.

non-disjunction

Amphiploidy: the formation of a fertile hybrid due to somatic doubling or complete __ after an event of allopolyploidy.

non-disjunction

Inbreeding: closely related members of a species __.

interbreeding

Outbreeding: members of a species which are not closely related __.

interbreeding

Hybrid vigour: an increase in the size, strength or other characteristic of a hybrid offspring formed by the __ between two different species.

interbreeding

Non-disjunction: where the chromosomes or chromatids do not separate as usual during __ of meiosis.

anaphase

Autopolyploidy: an abnormal number of chromosomes from parents of the same __.

species

Allopolyploidy: an abnormal number of chromosomes from parents of __ species.

different

Colchicine: a drug which inhibits spindle formation and increases the likelihood of complete __ during meiosis.

non-disjunction

Instant speciation: sudden change in __ number of offspring from parents over a single generation, meaning that they are no longer able to reproduce with the parent generation.

chromosome

Selection pressure: a biotic or abiotic environmental factor that causes a specific __ of an organism to be favoured.

trait

Mimicry: where one species adopts the phenotypic __ of another; for example, a palatable butterfly species taking on the colourings of a non-palatable species to avoid predation.

characteristic

Specialists: a species with a __ niche and specific requirements in order to stay alive.

narrow

Generalists: a species with a wide niche and larger range of __ conditions under which they can survive.

ecological

Prezygotic + name: a RIM which takes effect before the formation of a __ to prevent the formation of a viable offspring.

zygote

Post zygotic + name: a RIM which takes effect after the formation of a zygote to prevent the formation of a reproductively viable __.

offspring

Allopatric speciation: speciation due to physical __.

barriers

Sympatric speciation: speciation due to non-physical __.

barriers

Vicariance: a large-scale biogeographical event leading to large-scale allopatric __.

speciation

Niche differentiation: organisms, often of the same species, utilising different resources and __ within their environment differently.

interactions

Phylogeny: the evolutionary __ of a group of organisms, often visualized as a phylogenetic tree.

history

Clade: a group of organisms that includes a common __ and all of its descendants.

ancestor