biology natural selection

disruptive selection

disruptive selection

2 extremes are favoured over middle values

stabalizing selection

middle values are favoured over extremes

directional selection

one extreme favored over all other values

gene flow

Movement of alleles into or out of a population due to the migration of individuals to or from the population

genetic drift

chance events can cause allele frequencies to fluctuate unpredictably from one generation to the next

bottleneck effect

A change in allele frequency following a dramatic reduction in the size of a population, leads to lack of genetic diversity

founder effect

change in allele frequencies as a result of the migration of a small subgroup of a population

sexual selection

1 sex chooses the desirable traits of the other leading to an increase of individuals with the desired qualities to mate

artifical selection

human intervention in the form of selective breeding

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

antibiotic resistance

Resistance evolving rapidly in many species of prokaryotes due to overuse of antibiotics, especially in agriculture.

how to prevent antibiotic resistance

always take full antibiotic prescription, educate public about antibiotics, advance technology w/ phage therapy, use less in ag

What is the Hardy-Weinberg equilibrium?

Condition that occurs when the frequency of alleles in a particular gene pool remain constant over time.

What is the Hardy-Weinberg equation?

p^2 + 2pq + q^2 = 1

5 criteria for hardy-weinberg theory

no gene flow, no natural selection, no sexual selection, large population, no mutations

Evidence of Evolution

1. Fossil Record

2. embryology

3. homologous and analogous structures

4. molecular biology

Cladograms

a branching diagram showing the cladistic relationship between a number of species.

fossil record

shows how species have changed physiologically over time in relation to one another

embryology

common fetuses in early development

molecular biology

shows how dna/amino acid sequences have changed over time in accordance w enviroment

darwins theory of natural selection

1. Process of evolution through differential survival and reproduction

2. Variation exists within populations

3. Some variations are heritable

4. Organisms with advantageous traits are more likely to survive and reproduce

5. Over time, favorable traits become more common in a population