Species & Speciation Flashcards
What is the definition of a species?
A group of populations whose members have the potential to interbreed and produce viable, fertile offspring
What is reproductive isolation?
Biological barriers that prevent the process of interbreeding
What are the five types of biological barriers that induce reproductive isolation?
- Behavioural isolation
- Geographical isolation
- Temporal isolation
- Mechanical isolation
- Gametic isolation
What are sub-species?
A population within a species that has become genetically and/or physically distinct, but can interbreed with the wider population
What are ring-species?
Two populations that do not interbreed together but have gene flow through a number of overlapping, interconnected populations that can interbreed
What is speciation?
The process by which new species arise from existing species through different mechanisms
What type of speciation is geographical isolation?
Allopatric speciation
What type of speciation is non-geographical isolation?
Sympatric isolation
What is allopatric speciation?
Gene flow is interrupted when a population is geographically divided into sub-populations
What is sympatric speciation?
Gene flow is interrupted despite populations not being separated geographically
What are the three processes which can interrupt gene flow?
- Polyploidy
- Sexual selection
- Habitat differentiation
Polyploidy is a condition in which an organism has how many sets of chromosomes?
More than two sets
Autopolyploidy results from how many parental species?
Single parental species
Allopolyploidy results from how many parental species?
Multiple parental species
What are hybrid zones?
An area where two interbreeding species can meet, mate, and produce offspring of mixed ancestry
