Species Basics
his is a group of organisms that can interbreed and produce fertile offspring.
What is a species?
Speciation caused by geographic separation.
What is allopatric speciation?
rsolation that happens before fertilization.
What are prezygotic mechanisms?
Slow, steady evolution over time
What is gradualism?
The permanent loss of a species
What is extinction?
These are small local populations that mostly breed with each other
What are demes?
A sudden formation of a new species, often in plants.
What is instantaneous speciation?
Isolation that happens after fertilization
What are postzygotic mechanisms?
Long periods of no change followed by rapid evolution
What is punctuated equilibrium?
Normal, ongoing extinction over time.
What is background extinction?
A gradual change in traits across a geographic area is called this
What is a cline?
This must stop for speciation to occur.
What is gene flow?
Different mating behaviors preventing reproduction.
What is behavioral isolation?
When one species splits into many different species.
What is adaptive radiation?
A rapid loss of many species at once.
What is mass extinction?
A circular cline where populations at the ends can’t interbreed.
What is a ring species?
When organisms adapt to new food or lifestyle and separate.
What is sympatric speciation?
Offspring that cannot reproduce (like mules).
hybrid sterility?
When unrelated species evolve similar traits.
What is convergent evolution?
Main human cause of extinction.
What is habitat destruction?
When gene flow stops and populations become different, this process happens.
What is speciation?
This must stop for speciation to occur.
What is gene flow?
When sperm and egg cannot fuse
What is gamete incompatibility?
When species evolve together and affect each other.
What is coevolution?
When a species dies, this becomes open for others.
What is a niche?