Chapter 16 2
Terms
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- Define fossils...
- recognizable, physical evidence of an organisim that lived in the past.
- Genetic equilibrium is...
- the frequencies of alleles at a given gene locus remain stable, one generation after the next.
- Inbreeding refers to what?
- to nonrandom mating among closely related individuals, which have many identical alleles in common. Inbreeding is a form of genetic drift in a small poulation- that is within the group of relatives that are preferentially interbreeding.
- A bottleneck is what?
- a severe reduction in population size, as brought about by in tense selection pressure or natural calamity.
- Define population:
- A group of individuals of the same species occupying to a given area.
- What is lethal mutaion?
- a mutation that has severe effects on pheotype usually will result in death.
- Define allele frequencies...
- the abundance of each kind of allele in the population.
- Define gene pool...
- a pool of genetic resources that in theory at least is shared by all members of a population and passed on to the next generation.
- Polymophism is?
- the persistance of two qualivily different forms of a trait in a population.
- What is Darwin's theory of evolution by natural selection?
- A population can evolve (change over time) when individuals differ in one or more heritable traits that are responsible for differences in the ability to survive and reproduce.
- Fixation is what?
- means that only one kind of allele remains at a particular locus in the population; all individuals are homozygous for it.
- Define biogeography...
- the world distribution of organisms.
- What is a sampling error?
- A rule of probability, helps explain the difference.
- A neutral mutation is what?
- does not help or harm an individual. Natural selcetion can neither increase nor decrease the frequency of neutral mutations in a population, for hese do not have any discernible effect on the individual's change of surviving or reproducing.
- Define theory of uniformity...
- gradual, uniformly repetitive change.
- What is genetic drift?
- a random change in allele frequencies over generations, brought about by chance alone.
- We define biological evolution as ...
- heritabel changes in lineages, or lines of decent.
- Microevolution is ?
- refers to small-scale changes in allele frequenceis, as brought about by mutation, natural selection, gene flow, and genetic drift.
- Directional selection is?
- Allele frequencies that underlie a range of variation in phenotyples shift in a consistent direction. The shifts occur in reponse to a directional change in the environment or to one or more new environmental conditions. They also occur when a mutation appears and proves to be adapative.
- Mutation rate is what?
- the probability of its mutation during or in between DNA replications.
- Define comparative morphologly
- the systematic study of similariteis and ifferences in the body plans between major groups, such as different kinds of vertebrates.
- Disruptive selection is what?
- forms at both ends of the range of variation are favored and intermediate forms are selected against.