Chapter 13, 14, and 15 definitions

Darwin theory of evolution

Species change over time through natural selection

13.10 (1) - hardy-weinburg - 5 conditions for equilibrium

A population is significantly large, mating is random, there are no mutations, no gene flow, and no natural selection

Lamarck theory of evolution

Believes individuals evolved

13.6 - Mechanisms of evolution

Individuals don’t evolve, it’s the population, natural selection can only effect heritable traits, evolution is not goal directed and it doesn't lead to perfectly adapted organisms - it is just based on the natural variation that already exists

Artificial selection

Humans select specific traits in organisms by controlling their reproduction

Natural selection

Organisms that easily adapted to their environment were able to survive and produce more offspring

Genetic drift

Main cause of evolutionary changes

Bottleneck

Leads to a loss of genetic diversity when a population is greatly reduced

Founder effect

When a few individuals colonize a new habitat (increase recessive traits)

Directional

Shifts the overall makeup of the population by acting against individuals at one of the phenotype extremes

Stabilizing

Favors intermediate phenotypes

Disruptive

Typically occur when environmental conditions vary in a way that favors individuals at both ends of a phenotype (leads to new species)

Biological concept

Organisms have to be able to reproduce and make viable fertile offspring

Morphological concept

Look at physical traits

Ecological concept

Prevents organisms from interbreeding

Phylogenetic concept

Evolutionary history (ancestors)

Prezygotic

prevent mating or fertilization entirely

Habitat isolation

Not sharing the same habitat so they lack the opportunities to encounter each other

Temporal isolation

breeding at different times of the year (corpse flower)

Behavioral isolation

different courtship rituals

Mechanical isolation

physical incompatibility or reproductive parts

Postzygotic

Act as a zygote forms resulting in non-visible or sterile hybrid offspring

reduced hybrid vitality

two species that sometimes mate and produce unhealthy offspring

reduced hybrid fertility

hybrid of offspring is sterile

hybrid breakdown

hybrids in 1 gen are healthy but hybrids in the 2nd gen are unhealthy

Allopatric

Geographic barrier that isolates 2 species to prevent interbreeding

Sympatric

Occurs in the same area or population and is likely due to phenotypic variation

Major events in the history of life

Know how they affected macroevolution (slide 23)

15.5 half life - radiometric dating

Based on the decay of radioactive isotopes and can date rocks and fossils (establish earth’s history)

What caused macroevolution

Plate tectonics, mass extinction events, volcanic eruptions

Genus

first part of a binomial

Species

second part of a binomial

7 taxon system

Domain (Bacteria, Eukarya, and Archaea), Kingdom, Phylum, Class, Order, Family, Genus, Species

Homologous structures

molecular sequences, provide the evidence of common ancestry used to determine phylogeny (evolutionary history of a species or group of species)

Analogous structures

due to convergent evolution