Chapter 23 & 24 Flashcards
Darwin and Wallace proposed ___
evolution by natural selection
some of the variations among individuals are ___, they are passed on from parents to their offspring
heritable
there is ___ between individuals within a species for recourses like food, mates, and places to live.
competiton
many genes exist in 2 or more forms called ___
alleles
alleles code for slightly different versions of the same ___
protein
the differences in ___ cause the variation you see within a species
alleles
breeding plants and animals for desirable characteristics
artificial selection
artificial selection is also called ___
selective breeding
2 examples of natural selection
- evolution of antibiotic resistance in bacteria
- insecticide resistants in insects
evidence for evolution (5)
- fossil evidence
- anatomical evidence
- biogeographical evidence
- biochemical evidence
- embryological evidence
structures that were inherited from a common ancestor
homologous structures
stunted wings on an ostrich or the remnants of a pelvis in some whales and snakes are examples of ___
vestigial structures
the study of the distribution of plants and animals
biogeography
___ and ___ can be examined to determine how closely related species are
DNA
proteins
two or more genes derived from common ancestors are called ___
homologous genes
homologous genes in different species are called ___. they indicate the species share a common ancestor.
orthologs
gene transfer between species, such as from a bacteria to a eukaryotes or from a Neanderthal to a modern human.
horizontal gene transfer
development of a species
ontogeny
evolutionary history of a species
phylogeny
a local group of individuals of the same species
population
populations are ___, they can change from generation to generation.
dynamic
all of the alleles for every gene in a population
gene pool
most genes are ___; they exist as two or more alleles
polymorphic
the number of copies of a specific allele in a population divided by the total number of alleles for the specific genes in a population
allele frequency
the number of individuals with a particular genotype in a population divided by the total number of individuals in a population
genotype frequency
describes the relationship between allele and genotype frequencies in a population that is not evolving.
p^2+2pq+q^2=1
-equation for a gene that exists in 2 alleles
hardy-weinberg equation
conditions for hardy-weinberg (6)
- no new mutations
- no natural selection
- no advantage for any one allele
- large population
- no migration
- random mating
changes in the gene pool from generation to generation
microevolution
___ involves introduction of new genetic variation and evolutionary mechanisms that alter prevalence of genotypes
microevolution
extreme phenotypes are favored
directional selection
favors intermediate phenotypes
stabilizing selection
favors two or more different phenotypes
diversifying selection
two or more alleles are kept in balance
balancing selection
certain individuals possess certain traits that make them more successful in reproduction
sexual selection
the different appearance of the 2 sexes resulting from different secondary sex characteristics
sexual dimorphism
one sex competing amongst themselves from mating opportunities
intrasexual selection
one sex choosing mates based on desirable characteristics
intersexual election (mate choice)
changes in allele frequencies due to chance
genetic drift (this is not natural selection)
genetic drift includes the ___ and the ___
- bottleneck effect
- founder effect
a large population may be severely reduced in size by a disaster, the remaining individuals are unlikely to have the genetic diversity of the original large population
the bottleneck effect
genetic drift in a new isolated colony
the founder effect
changes in genes that do not effect reproductive success
-promoted by genetic drift
neutral variation
the flow of genes between populations by migrating individuals
the gene flow
inbreeding produces less fit homozygotes reducing a populations’ reproductive success
inbreeding depression
mutations give rise to new alleles- most are ___ (do not help survival) but some re useful and are favored by natural selection.
deleterious
