Honors bio evolution

Explain the evolutionary significance

Embryological similarities - this shows that from a developmental standpoints there is evidence for living things common ancestry

Homologous structures

Similar features of 2 diff. Organisms that share an evolutionary past

Analogous structures

Similar features that evolved independently

Vestigial structures

Used to serve a role, but serve no purpose now

Fitness

An organisms relative ability to survive and reproduce

Population

A group of organisms within an area that reproduce

Gene pool

The total of all the diff. Alleles in a given pop.

Allele frequency

Of times an allele occurs in a gene pool

Migration

Movement of organisms into or out of pop.

Genetic drift

When allele frequencies are changed by random events

Micro evolution

Evolutionary change in a small group over a short period of time

Founder effect

When a small pop. Starts an entirely new isolated pop.

Genetic bottleneck

When a pop. Is driven nearly extinct, then recovers

What did Lamarck believe

Organisms acquired traits through life experiences

What did both Lamarck and Darwin believe

Traits are passed onto generations (offspring)

What did Darwin believe

There was natural variation in pop. Of organisms & that the environment naturally those organisms with the greatest fitness

How did geologists influence Darwins thinking

Darwin started to view the world as much older than other biologists, and then he just assumed that slow, steady changes added up over time

Label the type of selection & explain

Stabilizing - the extremes selected against

Label the type of selection & explain

Directional-only one phenotype is selected against

Label the type of selection & explain

Disruptive - the average phenotype is selected against

List & describe the 3 causes of variation within a species

• Mutation - random changes in the genetic code can alter proteins

• Recombination(chromosomal changes can cause speciation)

• Sex(reduction division increases variability)

List & describe the five mechanisms of microevolution

• natural selection -environment selects for or against a trait

• Norandom mating-sexual selection can quickly affect gene pools

• Gene flow(migration)-movement of members into or out of a pop. Changes gene pools

• Mutation-changed to DNA can affect proteins which influence traits

• Genetic drift-random chance can shape evolution

Differentiate between the 2 types of genetic drift

Founder- when a small group from an oringinal pop. Starts a new pop.

Bottleneck - after a pop.Has been brought to near extinction, then recovers

What 5 criteria must be met for Hardy - Weinberg equilibrium

No natural selection, no mutation, no migration , large pop. , random mating

Describe the biological species concept

A species is defined as any organism that can reproduce and produce fertile offspring

Describe prezygotic& postzygotic barriers

Prezygotic - these preventa viable offspring from reproducing .

Postzygotic: these prevent living organisms from passing their genes to the next generation

classify the types of isolating mechanisms that fit into them

Prezygotic = geographical, temporal, behavioral, mechanical isolation

Postzygotic: hybrid sterility

What is adaptive radiation? Hows it possible?

Process by which a single species rapidly evolves into numerous diff. Species in short period of time. it occurs because there is a niche within an ecosystem that is unified ( ex. Galapagos islands )