exam 3 Flashcards
hierarchical organization
- aristotle
- species fall into natural groups, some better than others
- humans above animals, men above women
fixity of species
- working scientific theory
- empirical evidence, philisophical ideas
- discrete boundaries between species based on how things look
- species do not change over time, no extinction
natural theology
- all creation is due to activities of a Christian God
- discover nature = discover God
foundation of darwin and wallace
- darwin’s HMS Beagle voyage: lots of different organisms in different islands, fossils, similar behavior
- studied finches in the galapagos islands
- darwin’s voyage of the beagle notes 1838
- wallace writes him a letter from malaysia in 1858
- darwin’s origin of species 1859
success of an organism
survive and reproduce
components/postulates of natural selection
- individual members of population vary
- traits are passed from parent to offspring
- some individuals fail to survive and reproduce
- survival and reproduction are not determined by chance (but by advantageous traits)
evidence of natural selection: artificial selection
if we can do it with dogs and produce, why can’t nature do it
evidence of natural selection: comparative anatomy
organisms from different ancestries have same froms/structures
vestigial structures
a structure that no longer provides a function, but did for ancestors. also referred to as evolutionary baggage
convergent evolution
natural selection causing non-homologous structures that serve similar functions
analogous structures
structures with similar functions/appearance but different internal anatomies
evidence of natural selection: embryology
species with similar embryos likely have common ancestors, stages of development show different groups
evidence of natural selection: geographic distribution
similar species in different locations evolve differently (ex. mammals and marsupials)
evidence of natural selection: progression of fossil forms
shallower fossils more closely resemble modern organisms
neodarwinian synthesis
- reconciles natural selection with mendelism (mendel rediscovered early 1900s)
- inheritance is particulate (DNA)
- differential proliferation of phenotypes (advantageous)
- natural selection changes gene frequencies
- more successful genotype = more successful offspring (survival and reproduction)
population
all individuals of same species living in a given geographical area
gene
discreet segment of DNA that codes for a particular trait
gene pool
all the genes (and their alleles) of a population
allele frequency
relative proportion of each allele in the population
- 25 individuals, 50 alleles, 20/50 are B dark fur alleles, allele freq. = 40%
- if a species is not evolving, that frequency will not change
conditions for hardy-weinberg principle
- no mutations
- no gene flow
- very large population
- completely random mating
- no differential fitness
gene flow
movement of alleles to and from other populations
genetic drift
a random event that removes some alleles from a small population