Species Basics
This is a group of organisms that can mate and produce fertile offspring.
A species
This type of speciation happens when populations are separated by a physical barrier.
A allopatric speciation
This happens when species breed at different times.
A temporal isolation
Large evolutionary changes over long periods of time.
A macroevolution
When a species completely dies out.
It is called extinction
This term describes a small local population that mostly breeds within itself.
A deme
This type of speciation happens without physical separation.
A sympatric speciation
This happens when mating behaviors are different.
A behavioral isolation
Evolution happening slowly and steadily over time.
It is gradualism
Slow, natural extinction over time.
It is called background extinction
This is when traits change gradually across different geographic areas.
A cline
This type of speciation can happen very quickly, often in plants.
A instantaneous speciation
This happens when sperm and egg cannot join.
A gamete incompatibility
Evolution happening in quick bursts with long periods of little change.
A punctuated equilibrium
A major event where many species go extinct quickly.
It is called mass extinction
This keeps species separate by preventing interbreeding and keeping gene pools different.
A reproductive barriers (or isolation mechanisms)
What stops gene flow in allopatric speciation
A geographic isolation (like mountains, rivers, etc.)
This happens when offspring cannot reproduce.
A hybrid sterility
When one species splits into many different species to fill different roles.
It is a adaptive radiation
When unrelated species develop similar traits due to similar environments.
It is called convergent evolution
Why might the definition of species not work well for bacteria? (Critical thinking)
Because bacteria reproduce asexually and don’t need to interbreed.
(Outside Info)
Example: Apple maggot flies split into two groups based on different fruits without separation. What type of speciation is this
A sympatric speciation
(Outside Info)
Example: A liger (lion + tiger) is often large but has health problems. What type of isolation is this?
A hybrid disadvantage
(Outside Info)
Example: Darwin’s finches evolving different beaks on islands is an example of what?
It is a adaptive radiation (or divergent evolution)
When two species influence each other’s evolution (like predator and prey).
It is called coevolution