Biol 1407 Unit 1 (Ch 19-22) Review

Causes of gene flow

• Physical migration of organisms to another population

• Random mutations within a population

• Increased competition for resources

• Natural selection favoring certain traits

unrelated species evolve similar features or behaviors independently

• convergent evolution

• divergent evolution

• adaptive radiation

• co-evolution

random mating and no other selective pressures that lead to a change in frequency of alleles

• hardy-weinberg equilibrium

• genetic drift

• natural selection

• mutation

most common mechanism for sympatric speciation in plants

• polyploidy

• allopolyploidy

• hybridization

• genetic drift

he proportion of a specific allele (variant form of a gene) present within a population

• allele frequency

• genetic drift

• phenotypic ratio

• mutation rate

a reproductive barrier that prevents different species from interbreeding by stopping gametes from forming a zygote. Ex. temporal, mechanical, behavioral or habitat isolation

• prezygotic selection

• postzygotic selection

• genetic drift

• natural selection

characteristics of species that prevent or reduce the ability of species to reproduce with other species

• isolating mechanisms

• adaptive traits

• genetic drift

• ecological niches

a situation where a heterozygous genotype has a higher fitness than either homozygous genotype.

• homozygous advantage

• heterozygous advantage

• genetic drift

• natural selection

a group of organisms that includes all descendants of a common ancestor and that ancestor itself

• polyphyletic

• paraphyletic

• monophyletic

• holophyletic

the random fluctuation of allele frequencies within a population over time. It's a key mechanism of evolution, particularly in small, isolated populations, where random chance can cause significant shifts in genetic makeup.

• genetic drift

• natural selection

• gene flow

• mutation