vocab 1
Variation
genetic differences among organisms in a population
Niche
The role of an organisms plays in its environment
What are the Hardy - Weinberg equations for?
Morphological homologies
modified traits shared amongst different species
Speciation
creation of a new species
Fitness
the ability of an organism to survive and produce fertile offspring (bonus; what increases fitness?)
What determines the rate and direction of evolution?
ecosystem stability
5 conditions for hardy-Weinberg equilibrium
1) large population - no genetic drift, 2) absence of migration - no gene flow, 3) no net mutation - no genes are modified, deleted, or duplicated, 4) Random mating - no sexual selection, 5) absence of selection - no natural selection
Homologous/ analogous/ vestigial structures
variation in a structure that was present in a common ancestor / evolved independently in different species due to similar environmental conditions / reduced or obsolete features that serve little or no purpose for an organism
Reproductive isolation prevents _____ through ______
gene flow between populations; Pre zygotic and post zygotic barriers
Heritability
The ability to pass on adaptations to successive generations
Genetic variation
the genotypic and phenotypic difference between individuals in a population (bonus; genetic vacations increases the probability a population of organisms will survive under changing environmental conditions)
What is the Hardy Weinberg equation for finding the frequency of genotypes/ phenotypes and what do the variables stand for?
p^2 + 2pq + q^2 = 1 (p^2 = frequency of homozygous dominate genotype, 2pq = frequency of heterozygous genotype, q^2 = frequency of homozygous recessive genotype)
Pathogens
An infections agent that can produce a disease
Pre zygotic barriers
prevent production of a fertilized egg (Habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, gamete isolation)
role of an organisms plays in its environment
Artificial selection
the process by which humans select desirable traits in other species and selectively breed individuals with desired traits
What is the hardy Weinberg equation for finding the frequency of an allele and what do the variables stand for?
p+q = 1 (p = frequency of dominant allele, q = frequency of recessive allele)
Punctuated Equilibrium and Gradualism
evolution occurs rapidly after long period of stasis; evolution occurs slowly over hundreds of thousands/ millions of years
Post Zygotic Barriers
prevent a zygote from developing into a viable, fertile offspring ( hybrid inviability - mating results in a zygote, but comparability may stop the development, Hybrid sterility- hybrid offspring is vigorous but may be sterile, Hybrid Breakdown - First generation is viable and fertile, but resulting generations aren’t)
Genetic drift
the RANDOM change in the frequency of a particular allele within a population
Founder effect
a random process that reduces variation within a small population due to separation from a larger population (a river)
What can disrupt Hardy Weinberg equilibrium?
1) mutations, 2) non-random mating, 3) Gene flow, 4) genetic drift, 5) natural selection
Deleterious / adaptive traits
evolution occurs rapidly after long period of stasis / evolution occurs slowly over hundreds of thousands/ millions of years
Allopatric / Sympathies speciation
the evolution of a new species due to 1) individuals from the same population being geographically isolations over a long period of time / 2) individuals being reproductively isolated from a surviving ancestral population