What is natural selection
mechanism of evolution
How is evolutionary fitness measured
reproductive success
What does natural selection act on
phenotypic variations in poopulations
How does environmental change impact populations
applying selective pressures
How do humans affect variation in other species
artificial selection
When does convergent evolution occur
when similar selective pressures result in similar phenotypic adaptions in different populations or species
By which random occurrences does evolution occur
mutations, genetic drift (bottlenecks and founder effect), migrations/gene flow
How can differences in populations of the same species increase
reduction of genetic variation
What is the flow of evolution through mutation
mutation to genetic variation to phenotypes to natural selection
When is the Hardy-Weinberg model used and what are the conditions
used for describing and predicting allele frequencies in a nonevolving population. condition: large population size, absence of migration no net mutations, random mating, absence of selection
What is the Hardy-Weinberg equation
p2 + 2pq +q2 = 1
What is evidence of evolution in a population
changes in allele frequencies
Which populations are most susceptible to random environmental impact
small populations
Where is evolution supported
geography, geology, physical, biochemical, mathematical data
How can fossils be dated
age of surrounding rocks, rate of carbon 1-4 decay, geographical data
What do morphological homologies represent
features shared by common ancestry
What provides evidence for evolution and common ancestry
comparison of DNA nucleotide sequences and/or protein amino acid sequences
What evidence supports the relatedness of organisms in all domains
structural and functional evidence
What structural evidence indicates common ancestry in all eukaryotes
membrane-bound organelles, linear chromosomes, genes with introns
What continuous evolutionary support is there within populations
genomic changes over time, continuous changes in the fossil record, resistance to antibiotics, pesticides, herbicides, chemo drugs, development of pathogens
at do phylogenetic trees and cladograms model
phylogenetic trees- relationship between lineages, amount of change over time
cladograms- relationship between lineages
How are phylogenetic trees and cladograms created
analyzing loss or gain of genetic traits within a species population
Which type of data is best for phylogenetic trees and cladograms
molecular data
What can phylogenetic trees and cladograms show
speciation
Where can phylogenetic trees and cladograms be constructed from
morphological similarities of living or fossil species in DNA or protein sequences
What do phylogenetic trees and cladograms represent
constantly revised hypotheses
When does speciation occur
two populations become reproductively isolated from eachouther
What are species
a group capable of interbreeding and exchanging genetic information to produce viable, fertile offspring
What is punctuated equilibrium versus gradualism
punctuated equilibrium- rapid evolution after long stasis
gradualism- evolutions over hundreds thousands of years or more
When does divergent evolution occur
new habitats results in phenotypic diversification
What are the two forms of speciation
sympatric or allo patric
what maintains reproductive isolation and prevent gene flow between populations
prezygotic and postzygotic mechanisms
How can niches be affected by extinction
creates new spaces of explotation
How does genetic diversity influence populations survavial
diversity increases ability to responded to environmental changes
What is geological evidence for the origins of life
formed 4.6 billion years ago (bya) with hostile environmens until 3.9 bya with early fossils at 3.5 bya