bio test evolution Flashcards
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What are the evidences for evolution?
fossil record, biogeography, embryology, anatomy, molecular biology (dna), artificial selection
what is fossil record (related to evolution)
- the remains of past life, radioisotope reveal age, appear in chronological order in rock layers
what is biogeography(related to evolution)
study of past and present geographical distribution of species and when evolution occurred. species on islands often resemble species on closest continent
what is anatomy(related to evolution) (2 struc)
homologous structure: structures that have a similar structure but diff function (common a!)
analogous structure: do not have common evolutionary origin but preform similar functions
what is embryology(related to evolution)
study of pre-birth stages of an organism. similarities point to a common ancestor
what is molecular biology(related to evolution)
comparing DNA, similar = reflect of common ancestor
what is artificial selection(related to evolution)
involves repeatedly selecting for and purposefully breeding indv with traits useful to humans
what are vestigial structures
major functions but serve no useful function, ex: appendix, wisdom teeth
whats a transitional fossil
intermediate links between groups of organisms (tiktaalik: between mammal and fish)
what is antibiotic resistant
bacteria that evolved over time to become immune or resistant to antibiotics
what is microevolution
a gen to gen change in the frequencies of alleles within a population. evo on small scale
what is macroevolution
dramatic evo that results in new species. “speciation”
whats the hard-weinberg equilibrim
populations that do NOT change their gene pools over time are not evolving and are said to be in ahrdyweinerlquirim … condition: random sex rep
how do allele frequencies change?
mutation, gene flow, non-random mating, genetic drift, natural selection
explain mutation
a change that occurs in dna, randomly, often harmful and selected against, if occur in gametes.. can be passed on.
explain gene flow
movement of alleles from 1 population to another as a result of migration of indv.. new alleles can be introduced.
explain non-random mating
mating among indv on the basis of mate slection for a particular pheno or due to inbreeding. pref pheno: males often fight other males. inbreeding: closely related inv breed.. increases freq of homozy genotypes and harmful recessive alleles.
explain genetic drift (2 effects)
in small populations, the freuqnecies of certain alleles can be changed by chance alone
1) founder effect: change in gene pool when only a few indv start a new isolated pop. new pop limited. freq islands. lack of genetic diversity can lead to higher health conditions.
2) bottleneck effect: changes in gene distribution that result from a rapid decrease in pop size. ex: starvation.
explain natural selection
a blend of chance and sorting. increases the freq of alleles that provide reproductive advantage
what are the types of natural selection
stabalizing (MIDDLE), directional (SHIFT), disruptive (EXTREMES), sexual: appearance/behaviour ex; peacock
What is speciation?
the formation of a new species from an existing species (macroevolution)
What are the types of speciation?
Sympatric Speciation, Allopatric Speciation