Term
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Definition
| the origin of new species |
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Term
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Definition
consists of adaptation that evolve within a population, confined to one gene pool
- changes over time in population |
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Term
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Definition
refers to evolutionary change above the species level
- long time spans |
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Term
| biological species concept |
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Definition
states what a species is
- based on potential to breed rather than physical appearance |
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Term
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Definition
| the existence of biological factors (barriers) that impede two species from producing viable, fertile offspring |
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Term
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Definition
blcok fertilization from occuring by:
-impreding different species from attempting to mate
- preventing the successful completion of mating
-hindering fertilization if mating is successful |
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Term
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Definition
| two species encounter each other rarely, or not at all, beacuse they occupy different habitats, even though not isolated by physical barriers |
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Term
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Definition
| species that breed at different time of the day, different seasons, or different years cannot mix their gametes |
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Term
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Definition
| courtship rituals and other behaviors unique to a species are effective barriers |
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Term
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Definition
| morphological differences can prevent successful mating |
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Term
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Definition
| sperm of one species may not be able to fertilize eggs of anothe species |
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Term
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Definition
offspring of crosses between different species
- often have reduced fitness compared to parent species
typically rare due to numberous reproductive barriers |
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Term
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Definition
prevent the hybrid zygote fromo developing into a viable, fertile adult:
- reduced hybrid viability
- reduced hybrid fertility
- hybrid breakdown |
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Term
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Definition
| genes of the different parent species may interact and impair the hybrid's development |
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Term
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Definition
| even if hybrids are vigorous, they may be sterile |
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Term
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Definition
| some firt-generation hybrids are fertile, but when they mate with another species or with either parents species, offspring of the next generateion are feeble or sterile |
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Term
| morphological species concept |
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Definition
defines a species by structural features
- applies to asexual and sexual
- subjective |
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Term
| ecological species concept |
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Definition
views a species in terms of its ecological niche
- asexual and sexual
- emphasizes disruptive selection |
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Term
| phylogentic species concept |
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Definition
defines a species as the smallest group of individuals on a phylogenic tree
-sexual and asexual |
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Term
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Definition
gene flow is interrupted ro reduced when a population is divided into geographically isolated subpopulations
- even if contact is restored between popualations, interbreeding is prevented |
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Term
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Definition
speciation takes place in geographically overlapping populations
- less common
- can only occur if gene flow is reduced by polyploidy, habitat differentiation, & sexual selection |
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Term
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Definition
| the presence of extra set of chromosomes due to accidents during cell division |
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Term
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Definition
| an individual with more than two chromosome sets, derived from one species |
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Term
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Definition
| a species with multiple set of chromosomes derived from different species |
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Term
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Definition
| a region in which members of different species mate and produce hybrids |
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Term
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Definition
| occurs when hybrids are less fit than the parent species |
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Term
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Definition
describes periods of appatent stasis punctuated by sudden change
- not gradual |
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Term
| bioloigists compare ________ when grouping organisms |
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Definition
| morphology, phusiology, biochemistry, and DNA sequences |
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Term
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Definition
| a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring; they do no breed successfully with other populations |
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Term
| why do individuals of a population resemble each other? |
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Definition
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Term
| the biological species concept cannot be applied to _________ |
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Definition
| fossils or asexual organisms |
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Term
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Definition
1. habitat isolation
2. temporal isolation
3. behavioral isolation
MATING ATTEMPT
4. mechanical isolation
5. gametic isolation
FERTILIZATION
6. Reduced hybrid viabillity
7. reduced hybrid fertility
8. hybrid breakdown
VIABLE, FERTILE OFFSPRING |
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Term
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Definition
| the definition of ________ depends on the abililty of a population to disperse |
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Term
| When closely related species meet in a hybrid zone, there are three possible outcomes: |
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Definition
- strengthening of reproductive barriers
- weakening of reproductive barriers
- continued formation of hybrid individuals |
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