BIOL 117 Module #2

What are two factors for a new species to form?

Genetic isolation and genetic divergence.

What are the major categories of speciation events?

Allopatric and sympatric.

What is allopatric speciation?

Genetic isolation due to geographic separation.

What is sympatric speciation?

Genetic isolation without geographic separation.

What are the two forms of allopatric speciation?

Dispersal and vicariance.

What is dispersal?

Migrating away.

What is vicariance?

A barrier that forms in a population.

How does genetic isolation occur with sympatric speciation?

Behavior changes and genetics/ploidy drift.

How else does sympatric speciation occur?

It can be due to errors in meiosis.

What is autoployploidy?

Self fertilizing.

What is allopolyploidy?

Different fertilizing parents.

What is taxonomy?

Scientific field of naming and classifying organisms.

What is a species?

An evolutionary independent population or group of populations.

What is the biological species concept?

Naturally occuring groups of organisms that interbreed in nature, produce viable and fertile offspring, cannot produce viable and fertile offspring with members of other species.

What are the stages of reproductive isolation?

Prezygotic, mating attempt, and post zygotic.

What mechanisms of reproductive isolation occur in the prezygotic isolation?

Temporal isolation, habitat isolation, and behvaioral isolation.

What is temporal isolation?

Different times.

What is habitat isolation?

Different habitats.

What is behavioral isolation?

Behavior is a turn off.

What are the two mechanisms of reproductive isolation for the mating attempt?

Mechanical isolation and the gametic isolation.

What is mechanical isolation?

Not physically compatible.

What is gametic isolation?

Gametes may not be compatible.

What are the mechanisms of reproductive isolation in the postzygotic stage?

Reduced hybrid viability, reduced hybrid fertility, and hybrid breakdown.

What is reduced hybrid viability?

Zygote fails to divide or grow to reproduce.

What is reduced hybrid fertility?

Can’t make offspring at all.

What is hybrid breakdown?

Their offspring is sterile.

What are disadvantages of biological species concept?

Reproductive isolation cannot be evaluate in fossils, species that reproduce asexually, and closely related population that are isolated from one another.

What is the morphological species concept?

Based on morphological features (the form of the organism).

What are the disadvantages of the morphological species concept?

Subjective and polymorphic species.

What is the phylogenetic species concept?

Create a tree of species to connect many species together.

What are the disadvantages of phylogenetic species concept?

Limited data and many more species.

What is the big picture of the species concepts?

Correctly identifying species.