Evolution Ms73-78 Flashcards
what did Georges Buffon do?
species change over time due to random chance(mutation) and environmental pressures (adaptation)
what did Georges Cuvier do?
used fossil evidence to show extinct related to extant
what did Thomas Malthus do?
survival of the fittest
what did Charles Darwin do?
Descent with modification (Natural SelectionP)
what is natural selection?
- competition in a genetically varied population
- survival of the fittest
- speciation(evolution dependent on different environments
what are the concepts of natural selection?
- biological fitness; ability to survive and reproduce
2. differential reproduction; fitter individuals reproduce more
what was the proposed mechanism for evolution in the joint paper between Charles Darwin and other?
Natural Selection
what is the definition of evolution?
theory: a change in the gene pool of a population
what must be present for evolution?
genetic variation
how does genetic variation arise?
mutation, immigration, emigration
what did the Galapagos Islands show examples of to Darwin?
adaptations resulting from different selective pressures
what do the fossil records show about different types of animals?
fish->amphibians->reptiles-> birds, mammals
fossils provide evidence for what?
descent w/ modification (similarities)
and
stepping stone species(transitional)
embryonic development showed evidence for what?
common ancestry (striking similarities)
what are homologous structures?
traits that were once common but are now different due to environmental pressures (phalanges)
what are vestigial structures?
unused traits that were once used before
what are analogous structures?
arise from convergent evolution; populations under similar environmental pressures may develop similar traits
what did the universal genetic code provide evidence for?
all life shared a common ancestor
what is Artificial Selection?
selection of a desired trait led to selective breeding
what is microevolution?
change in a populations gene pool from generation to the next
what is the Hardy-Weinberg equation?
p² + 2pq + q² = 1
what does the p² represent?
allele frequency of RR to get expected genotype
what does the 2pq represent?
allele frequency of Rr to get expected genotype
what does the q² represent?
allele frequency of rr to get expected genotype
what 4 mechanisms contribute to evolution?
mutation
gene flow
genetic drift
natural selection
what is gene flow?
migration between populations
what is genetic drift?
loss of individuals not related to biological fitness
what can genetic drift cause?
genetic bottleneck; reduces genetic variation and thus lowers the probability of natural selection shifting the population towards adaptation
what is the only mechanism contribution got evolution that is NOT random?
natural selection
what are the three types of natural selection?
directional selection
stabilizing selection
disruptive selection
define selective pressures?
environmental factors affecting reproduction and survival based on a niche
define adaptive radiation?
rapid evolution of multiple new species from an ancestral species due to difference in niches
three kinds of macroevolution?
divergent (branch off)
convergent (converge onto same traits)
co-evolution (evo. of one causes evo. of other)
what is Allopatric Speciation?
formation of new species due to population isolation
what is rapid Allopatric Speciation?
adaptive radiation
what are the two kinds of reproductive barriers?
pre-zygotic
and
pst-zygotic
what are the 6 pre-zygotic barriers?
behavioral mechanical geographic ecological temporal gametic
what is the post-zygotic barrier?
when a zygote does not produce a viable, fertile offspring
what did primates coincide with?
extinction of Dinosaurs
characteristics of primates?
opposable thumbs large brain flexible shoulder joints binocular vision->depth perception 5fingers/toes
what family are humans in, along with all great apes?
Hominidae
what are great apes also known as?
hominids
Great Ape characteristics?
tool use
symbolic language
deceit
what are humans?
hominins
first bipedal human ancestor?
Lucy, A. afarensis
how is bipedalism possible?
arched feet, larger knee joints, angle of femur bones
