Chapter 24 Review

process by whihc one species splits into two or more species

changes over time in allele frequencies in a poupluation

broad pattern of evolution over long time spans

Speciation forms a bridge ebtween what?

Latin for kind or appearance

definition of a species as a population or group of populations whose members have the potential to interbreed in nature and prodcuce viable fertile offspring, but do not produce viable fertile offspring with members of such groups

transfer of alleles between populaations

existence of nbiological factors (barriers) that impede members of two species from producing viable, fertile offspring

pffs[romg tjat resi;t frp, am omters[ecofoc ,atomg

a reprductive barrier that impedes mating between species or hinders fertilization if interspecific mating is attempted

a reproductive barrier that prent hybrid zygotes produced by two different species from developing into viable, fertile adults

two species that occupy different habitats within the same area may encounter each other rarely, if at all, even though they are not isolated by obvious physical barriers, like mt. ranges

species that breed during different times of the day, different seasons, or different years cannot mix their gametes

courtship rituals that attract mates and other behaviour unique to a species are effective reproductive barriers, even between closely related species. Such behavioral rituals enable mate recognition- a way to identify potential mates of the same species.

a way to identify potential mates of the same species

mating is attempted, but morphological differences prevent its successful completion

sperm of one species may not be able to fertilize the eggs of another species. For instance, sperm may ot be able to survive in the reproductive tract of females of the other species, or biochemical mechanisms may prevent the sperm from penetrating the membrane surrounding the other species' eggs

The genes of different parent species may interact in ways that impair the hybrid's development or survival in its environment

even if hybrids are vigorous, they may be sterile. If the chromosomes of the two parent species differ in number or structure, meiosis in the hybrids may fail to produce normal gametes. Sunce the infertile hybrids cannot produce offspring when they mate with either parent species, gnes cannot flow freely between the species.

some first-generation hybrids are viable and fertile, but when they mate with one another or with either parent species, offspring of the next generation are febele and sterile.

a definitioin of species as the smallest groups of individuals that share a common ancestor, forming one branch on the tree of life

a definition of species in terms of measurable anatomical criteria

a definition of species in terms of ecological niche, the sum of how members of the species interact with the nonliving and living parts of their environment

the formation of new species in populations that are geographically isolated from one another

the formation of new spewcies in populations that live in the same geographic area

a chromosomal aberration in which the organism possesses more than two complete chromosome sets; is the result of an accident on cell division

a fertile individual that has more than two chromosome sets as a result of two different species interbreeding and combining their chromosomes

an individual that has more than two chromosome sets that are all derived from a single species