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what evidence did Darwin use to formulate his hypothesis of evolution by natural selection?

Darwin's hypothesis was supported first by Malthus' work on population growth which determined that not all offspring survive to adulthood to reproduce. Darwin's observations on Galapagos of differences among species and his investigations into the husbandry of domesticated animals led him to his conclusion that traits which best adapted their owner to their environment were those perpetuated and increase in the population.

how do organisms become adapted to their environment? describe this process of natural selection that leads to this adaptation

gene variations pass traits from parents to offspring. not all offspring live, those whose traits are best suited to the environment will be those populating most of the following generation, which will in turn reflect a higher percentage exhibiting that adaptive trait.

describe how evolution is supported by the fossil record, the anatomical record, and the molecular record

The fossil record supports evolution by the dating and ordering of dinosaur fossils which have been found, showing a progression of changes over a span of time.
The anatomical record is evidence for evolution in the similarities found between embryonic forms of varying vertebrates, homologous structures such as forelimbs, and analogous structures, or similarities brought about by convergent evolution, meaning populations in like environments developing the same traits in adaptation.
The molecular record in support of evolution includes genomic comparisons that confirm correspondence between two organisms' relative evolutionary distance and the number of their genomic differences. ALSO PROTEINS pg 253

Further molecular evidence for evolution is the MOLECULAR CLOCK. 253

what are the 5 agents of evolution, evolutionary forces that have the potential to significantly alter allele and genotype frequencies? which one changes the allele frequency from the random loss of alleles in small populations due to chance occurrences? which is the ultimate source of genetic variation?

five agents of evolution:
MUTATION: change in nucleotide sequence in DNA; the ultimate source of genetic mutation.
MIGRATION: the movement of individuals between populations
GENETIC DRIFT: usually in small populations, the loss of alleles due to chance event which kill off individuals, or new alleles introduced into a young (newly formed) population
NONRANDOM MATING: sexual selection based on physical characteristics, or inbreeding, as in self-pollenating plants.
selection: the only form that produces adaptive evolutionary change

describe the three kinds of natural selection. which kind acts to eliminate the intermediate phenotypes?

stabilizing - eliminates extremes from a spectrum of phenotypes
disruptive - acts to eliminate the intermediate phenotypes
directional - one extreme of the phenotype array is favored

what is reproductive isolation? what role does it play in the evolution of new species?

reproductive isolation is the condition in which a reproductive barrier keeps two species from interbreeding or results in an offspring incapable of reproduction

a great deal of research has been done on Darwins finches over the last 70 years. The research
a. seems to contradict Darwin's original ideas
b. seems to agree with Darwin's original ideas
c. does not show any clear patterns that support or refute Darwin's original ideas.

b. seems to agree with Darwin's original ideas

one of the major sources of evidence for evolution is in the comparative anatomy of organisms. features that have a similar look but different structural origin are called
a. homologous structures
b. analogous structures
c. vestigial structures
d. equivalent structures

a. homologous structures

The Hardy-Weinberg equilibrium allows scientists to study
a. natural selection
b. microevolution
c. isolating mechanisms
d. punctuated equilibrium

b. microevolution

a chance event that causes a population to lose some individuals and hence a loss of alleles to the population, results in
a. mutation
b. migration
c. selection
d. genetic drift

d. genetic drift

selection that causes an extreme phenotype to be more frequent in a population is an example of
a. disruptive selection
b. stabilizing selection
c. directional selection
d. equivalent selection

c. directional selection

a key element of Ernst Mayr's biological species is
a. homologous isolation
b. divergent isolation
c. convergent isolation
d. reproductive isolation

d. reproductive isolation

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