Definitions

Simiar functions w/o close relationship

-similarity is result of convergent evolution (evolve independently of each other)

Similarity of structures due to common ancestry regardless of function

Organs w/ no discernable function

• ex: coccyx of humans
• legs of snakes and whales

Products of nature that can only be explained in light of evolution ("ghosts of evolution past")

ex: avacado

Adaptations that evolved originally for a different function

ex: feathers on birds (evolved as thermoregulation as opposed to flight)

• -study of organismal development
• -more closely related organisms should share more of their development

ex: we all had gills at some point and had a 2 chamber heart

Genetics = Study of heredity

-we should share more of our DNA w/ those organisms we are more closely related to

ex: chimpanzees and humans share 98% of DNA

those individuals with traits (= adaptations) best suited to the local environment will generally leave more fertile offspring

Merging of evolutionary and genetic research/thought

a group of individuals of the same species in the same place, at the same time

p² + 2pq + q² = 1

• 1 Extremely large population size
• 2 no mutations are occuring
• 3 no selection happening (ex: no evolution)
• 4 random mating
• 5 no gene flow

A generation-to-generation change in a populations frequency of allels

A change in the gene pool of a small population due to chance

A drastic reduction in population size

-only a few survive--->therefore certain alleles are overrepresented and others are underrepresented (or lost)

ex; cheetas (10,000yrs ago & 19th century)

Only a few individuals w/ a different genetic make-up start a new population

• ex: 1814, 15 British founded a colony on Tristan de Cunha (in the middle of the atlantic ocean)
• -one had rare retinitis pigmentosa allele
• -by 1960's, of 240 descendents, 4 had the disease and 9 were known carriers

• A gain/loss of alleles from a populationby the movement of individuals/gametes into or out of a population
• -if gene flow increases, it will decrease the difference among populations

The raw (original) source of genetic variation

Leads to variation between population = geographic variation

• -bc environmental factors are likely to vary across the range of a species
• -the main driver of microevolution

Select one phenotype over another phenotype

Select against the most common phenotype which drives the evolution of 2 very different phenotypes

Select against both extremes (favor most common, intermediate phenotype)

-most common

Maintain multiple alleles, maintains 2 or more phenotypes at stable frequencies

Individuals who are heterozygus for a certain trait have greater fitness than homozygus individuals

The frequency of any 1 phenotype declines if it becomes too common

• ex: predator prey interactions
• side blotched lizards (rock, paper, scissors)

Variation that has little or no affect on reproductive success---> it is not selected for or against

-while this variation may not have any effect today, it may have an impact in the future if the environment changes

Natural selection for mating success

-can lead to sexual dimorphism

Within a sex

-competition for mates by individuals of the same se

• ex: peacocks-best plumage
• Irish elk-biggest antlers

• 1 production of diploid cells
• 2 meiosis-production of gametes (to eliminate errors of
• recombination)
• 3 sex is good if its optional
• 4 selection of sexiness
• 5 maintained by the good, the bad and the ugly

Maintainance of beneficial mutations

-the population can evolve faster

Weeding out the bad mutations

Avoid boom/bust cycles caused by parasites

-the Red Queen Hypothesis

The major changes in the history of life

• ex: origin of new species
• origin of biological novelties (ex: wings)
• explosive diversification
• mass extinction

• -produce fertile offspring
• -populations
• -behavioral interactions
• -morphological features

A species is a population or group of populations whose members have the potential to interbreed in nature to produce fertile offspring

• Alternatives:
• 1 morphological - physical traits
• 2 ecological
• 3 genetic similarity

before fertilization

• a mechaanical isolation-the parts dont fit
• b behavioral isolation-ex: distinctive odors, calls, mating
• rituals
• c habitat isolation
• d temporal isolation-different breeding seasons
• e gametic isolation-no union of the male and female
• gametes

(after fertilization)

• a hybrid inviability
• b hybrid sterility
• c hybrid breakdown

Dies young and doesn't reach sexual maturity

No functional gametes produced by the hybrid

ex: mules

Offspring are feeble/sterile

Geographic barrier that physically isolates a splinter population

• -many splinter groups don't survive
• -the splinter population MUST be reproductively isolated

• New species originates w/o geographic isolation w/in the parent population.
• -most common

• a polyploidy-extra set of chromosomes (common in
• plants)
• b habitat differentiation
• c sexual selection