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AP Bio Chapter 24
| Word | Definition |
|---|---|
| macro evolution | the origin of new taxonomic groups |
| Speciation | the origin of new species |
| anagenesis or phyletic evolution | the accumulation of changes associated with the tranformation of one species into another |
| Cladogenesis or branching evolution | the building of one or more new species from a parent species that continues to exist |
| species | a latin word meaning "kind" or "apperance" |
| biological species concept | emphasizes reproductive isolation, defines a species as a population or group populations whose members have the potential to interbreed with one another but cannot produce viable, fertile offspring with members of other species |
| Prezygotic barriers | impede mating between speicies or hinder the fertilization |
| habitat isolation | two species that live in different habitats within the same area may encounter each other rarely, if at all, even though they are not technicallt geographically isolated |
| behavioral isolation | specials signs that attract mates |
| temporal isolation | two species that breed during different times or day, seasons, or years cannot mix their gametes |
| mechanical isolation | closely related species may attempt to mate but fail to consummate the act beacuase thar are anatomically incompatible |
| gametic isolation | when the gametes refuse to make a zygote |
| post zygotic barriers | preventsthe hybrid zygote from developing into a viable, fertile fetus |
| reduced hybrid vialbility | when prezygotic barriersa are crossed and hybrid zygotes are formed, genetic incompatability between two species may abort development of the hybrid at some embryonic stages |
| reduced hybrid fertility | reproduction isolation is intact if the hybrids are completely or largelt sterile |
| hybrid break down | when the hybrid offspring mate with one another or with different species, offspring of the next generation or feeble or sterile |
| morphological species concept | the idea that species are defined by measurable anatomical criteria |
| recognition species concept | emphasizes mating adaptations that become fixed in a population as individuals "recognize" certain characteristics of suitable mates |
| Cohesion species concept | emphasizes cohension of phenotype as the basis of species integrity, with each species defined by its integrated complex of genes and set of adaptations |
| Ecological species concepts | emphasizes specific roles (niches), their positions and functions in the environment |
| evolutionary species concept | emphasizes evolutionary lineages and ecological roles |
| allopatric speciation | a geographical barrier that physically isolates populations initially blocks gene flow |
| sympatric speciation | intrinsic factors, such as non random mating or chromosomal changes, that alter gene flow, become gradually genetically isolated even though their ranges overlap |
| adaptive radiation | the evolution of many diversely adapted species from a common ancestor, darwin's finches |
| polyploidy | accidents in cell division that result in extra sets of chromosomes |
| autopolyploid | an individual that has more than two chromosome sets, all derived from a single species |
| allopolyploid | the contribution of two different species to a polypolid hybrid |
| hybrid zone | a region where two related populations that diverged after becoming geographically isolated make secondary contact and interbreed where their geopgraphical ranges overlap |
| puntuated equilibrium | a model that says species diverge in spurts of rapid change, instead of slowly and gradually |
| exaptation | a structure that evolved in one context and became co-opted for another function |
| allometric growth | a difference in the relative rates of growth of various parts of the body, helps shapes an organism |
| paedomorphosis | a sexually mature adult retains features that were juvenile structures in its evolutionary ancestors |
| heterochrony | a general term for evolutionary changes in the timing or rate of development |
| homeostasis | alteration in what biologists are fond of calling the bauplan of an organism(basic body design) or spatial arrangement of body parts |
| species selection | analogous to the production of a trend within a population by natural selection |