Quiz 2

Darwin’s went on an observational voyage in

1831-1836

Darwin in Argentina

found fossils of extinct ancestors or the armadillos

Darwin in the Galapagos

found different shaped forties shells and different species of finches across the islands

Variations in traits

influence an individuals ability to secure resources

Artificial selection

human directed, intentional breeding based on certain characteristics

Darwin’s big idea

if humans could select for certain traits could nature do the same?

________ helped Darwin come to the conclusion of natural selection

Wallace

Natural selection

differential survival and reproduction among individuals of a population with varying traits

3 conditions for natural selection

must have variation, must be heritable, and have different reproductive success

Reproductive success

more offspring produced than can survive, compete for resources, better survivors

Fitness

a measure of relative reproductive success

Evolution is not _________ but just works to make alleles ________ __________ to survive

progressive; good enough

Adaptation

a trait that increases survival and influences fitness

The theory of evolution replaced typological thinking with ________ thinking

population

Stabilizing selection

intermediate phenotype, where the medium mix of alleles survives best

Directional selection

one extreme phenotype where either ends of the spectrum are selected for

Disruptive selection

both extremes in a phenotype are selected, both ends of the spectrum

Balancing selection

no phenotype has a distinct advantage over another

Sexual selection

traits that result in greater fit because they are more attractive to the opposite sex, usually mean they are more physically fit/ healthy

Intersexual selection

the mate chooses which individual to breed with

Intrasexual selection

individuals of the same sex compete with each other to obtain mates

Bateman-Trivers hypothesis

traits that attract opposite sex are more elaborate in males and eggs are more energetically costly to make than sperm

Female fitness (BTh)

limited by the ability to gain resources needed to produce more eggs and healthier offspring, produce relatively few offspring in their lives

Male fitness

limited by the number of females he can mate with, can mate frequently because sperm is energetically inexpensive

Sexual selection should act more strongly on __________

males

Honest signals of male genetic quality….

indicate males that care for young or that provide resources for females

Monopolize mating

male wins territory from other males and now has access to the females in that area

Sexual dimorphism

traits differ between sexes of the same species

Natural selection if the only evolutionary process that results in ____________

adaptation

Genetic drift

change in allele frequencies in population due to chance

Sampling error

what genetic drift is known as in statistics

Drift occurs in every population especially ___________ populations

small

Genetic drift is __________

random

Founder effect

when a group of individuals establish a new population in new area, only with their alleles

Gene flow

the movement of alleles between populations, when individuals leave one population, join another, and breed

Gene flow ____________ allele frequencies between source and recipient populations

equalizes

Evolutionary mechanisms of natural selection and genetic drift _____________ genetic diversity over time

reduce

Mutation ____________ genetic diversity

restores

Point mutation

change in a single base pair in DNA, may result in different amino acids in a polypeptide, may change regulation and or expression

Chromosome-level mutations

change in the number or composition of chromosomes, like gene duplication

Lateral/ horizontal gene transfer

the transfer of genes from one species to another

Mutations usually result in mutations that ____________ fitness

lower

Purifying selection

selection that usually removes deleterious alleles due to mutation

Mutation alone rarely changes allele ______________

frequencies

Polymorphism

when a gene has more than one possible trait

Mutation is the ________________ source of genetic variation

ultimate

Antibiotics

target structures only in bacteria cells

Natural selection in bacteria

antibiotics allow randomly resistant bacteria to survive and reproduce, this population increase

Rifampin

an antibiotic that works by binding with M. tuberculosis RNA pol and preventing transcription

Selection pressure

the thing that weeds out alleles, works against unfit alleles of traits