BIO108 Final Concepts

Causes of phenotypic variation

• genetic variation

  • mutations

  • crossing over

  • independent assortment

  • random fertilization

• environment

  • diet, activity, soil, predators

Phenotypes are based on…

the environment

IN DIPLOIDS mutations can be…

recessive and hide from selection

Lamarchianism believed that more/less use resulted in….

development/evolution

Darwin beliefs

• unity = shared ancestor

• diversity = unique adaptations

A population having the same fundamental traits w/ variation shows…

a common ancestor but different pressures

Large morphological differences in a timeline can be explained by…

extinction

Darwin observations

1. members vary in inherited traits

2. all species produce more offspring than can be supported in the environment because most aren’t fit

Darwin inferences

1. Individuals w/ favorable traits are more likely to reproduce

   1. Because unfit individuals die, favorable traits accumulate in the population

Darwin reasoning

natural selection is like artificial selection just much slower

Evidence for evolution

• direct observation

• homology

• fossils

• biogeography

Directional selection occurs when…

when the environment changes or population migrates

Stabilizing selection results in…

• less genetic variation

• maintains a status quo

Examples of harmful mutations are…

• deletion

• duplication

• rearrangement

Examples in neutral mutations are….

• in noncoding regions

• redundant code

Lamarckian evolution believes that…

more/less use = development

Genetic drift can cause genes to…

disappear

A cause of the founders effect can be….

habitat fragmentation

Gene flow can…

increase fitness of a population, limit speciation, and prevent range expansion

Two population can be considered a single population when…

gene flow is high

The main issue with the biological species concept is….

it doesn’t account for high/low gene flow (bears/fossils/asexual reproduction)

The main issue with the morphological species concept is…

it doesn’t account for convergent evolution (sharks/dolphins)

The main issue with the ecological species concept is…

it doesn’t account for organisms that share the same niche

Allopatric speciation allows subpopulations to…

evolve independantly

Sympatric species have stronger…

reproductive barriers

Evolutionary change can be rapid in…

punctuates equilibria

DK (Donkey Kong)

Domain Kingdom

PC

Phylum Class

OF (Only Fans)

Order Family

GS (Get Sum)

Genus Species

A positive result of gene duplication is…

there are extra genes, which allow more opportunities for novel adaptations

Horizontal transfer occurs through…

transposable elements, plasmids, viral infection, and fusion

Eukaryotes can get genes from…

prokaryotes and archaea