Darwin: Main dude of evolution, proposed idea of evolution via natural selection

Natural Selection: Nature dictates which organisms will survive and reproduce the best

• Driving force to evolution

• All about an organism’s ability to survive and reproduce

4 principles of Natural Selection:

Overproduction: Reproduce more than can survive

Variation: Organisms within the population vary

Selection: Some organisms survive and reproduce better than others/they are more fit

Adaptation: Genes of the more fit organisms start to increase in the population

Evolution: Descent with modification with genetic inheritance

Types of Evolution:

Stabilizing Selection: The average phenotype is selected for

Directional Selection: One extreme phenotype is selected for

Disruptive Selection: Both extremes are selected for

Gene flow: Immigration/Emigration of genes in a population

• Immigration: individuals moving into an area and bringing their genes with them

• Emigration: individuals leaving an area thus removing their contribution of genes to the population

Gene pool: All the genes/alleles in a population

The Founder Effect: A small population leaves to colonize a new area (bringing only their genes with them) (Blue Fugate Family)

Bottleneck: A natural disaster occurs and the survivors are the ones who reproduce

Are small gene pools bad?: Yes, recessive/bad alleles will be more common in the population. Without that high genetic diversity, there’s a high chance they might not adapt to its environment (Irish potato famine)

Species: a group of closely related organisms that are very similar to each other and are capable of interbreeding and producing fertile offspring

Speciation: the formation of new and distinct species in the course of evolution

• Allopatric: two populations of the same species become isolated from each other due to geographical changes

  EX: River, Mountain, Ocean

Sympatric: two groups of the same species live in the same geographic location but they evolve differently until they can no longer interbreed

• Post-zygotic: Fertilization will occur

  • offspring can’t reproduce

  • Offspring will not survive

  • OR embryo will not develop

• Pre-zygotic: Fertilization will not occur

  • Behavioral: individual develop different behaviors that begin to isolate them

  • Temporal Isolation: populations in the same habitat reproduce at different times

  • Habitat Isolation: organism lives in the same area but occupy a different habitant

Hardy Weinberg Law:

• 1) No mutation

• 2) Populations are large

• 3) No gene flow

• 4) No natural selection

• 5) Mating is random

Evidence of Evolution/definitons

Homologous structures: structures look familiar because they share a common ancestor

Analogous structures: structures look familiar because the structures are used for the same function (not from common ancestor)

Vestigial structures: a structure we don’t use anymore (appendix), but we still have it in our bodies, so our ancestors must have needed it.

Molecular/DNA: if two species have similar DNA sequences, they share a common ancestor and must have changed over time into different species

Prove Evolution!!! :)

Fossils: resemble species we see today, they show change over time

Geography: species in similar environments deal with similar pressures to adapt in the same way

Embryos: embryos look the same in earthy stages, so they must share a common ancestor in the past

Homologous Structures show…: common ancestors; similar among species

Adaptation: a structure/behavior that helps and organisms survive and reproduce

Types of Adaptations:

Camouflage: Blending in with your surroundings

Mimicry: Pretending to be something you’re not

Defense Mechanism: Something to combat your predator to defend yourself

Sexual Selection: Female choice drives the evolution process— females only mate with certain males that have the traits they like, so the males develop weird structures or behaviors to impress the females. Since only those specific males’ genes get passed on, it changes the genetics of the population

Coevolution: organisms adapt/evolve in response to one another

Artificial Selection: Unnatural selection - humans selectively breed organisms the way we want. It’s not the environment doing it, it’s humans doing it

Pesticide resistance: Some may have a mutation for resistance/ ones with resistance survive and reproduce/they pass down resistance gene/whole population is resistant