Speciation and Macroevolution Flashcards

Flashcards reviewing key concepts from the Speciation & Major Patterns in Evolution lecture.

What is allopatric speciation?

Speciation in which the initial block to gene flow is a geographic barrier that physically isolates the new population.

What is sympatric speciation?

Speciation without geographic isolation, where genetic change in a subpopulation occurs leading to reproductive isolation.

Name a mechanism of sympatric speciation.

Disruptive selection or polyploidy.

What is polyploidy?

An extra set of chromosomes.

Give an example of a plant species that is a polyploid.

Oats, potatoes, bananas, strawberries, peanuts, apples, sugarcane, wheat, or coffee.

What type of speciation is exemplified by squirrels separated by the Grand Canyon?

Allopatric speciation

What is the term for a nucleus containing three or more copies of chromosomes?

Polyploidy

What process is occurring with fish in the Congo River?

Speciation due to river topology leading to reproductive isolation.

If river topology prevents fish from swimming to the other side of the river, what type of speciation might occur?

Allopatric speciation

What facilitates divergence when colonizing individuals arrive on islands?

Founder's effect

What are endemic species?

Species found only in one place

What is adaptive radiation?

One common ancestor gives rise to many species adapted to unique ecological conditions or resources

What are some observable signs of evolution?

Fossils and extant (living) organisms

What do fossils show?

Transitional forms of species

What do homologous body parts illustrate?

Evolutionary relationships

What are vestigial structures?

Remnants of features that served important functions in an organism’s ancestors.

What does embryology demonstrate?

Vestigial and homologous traits

What type of evidence is used from the past and present distribution of organisms?

Biogeographic evidence

What can continental drift impact?

Reshaping the physical features of the planet

Continental drift leading to separation of an ancestral species is an example of what type of speciation?

Allopatric speciation