Speciation Flashcards
What is speciation?
The process by which one species splits into two
What does species explain?
The similarities and differences
What is micro evolution?
Changes over time in allele frequencies in a population
What is macro evolution?
Broard pattern of evolution over long time spans
What is gene flow?
Exchange of genes between gene populations as a result of movement of interbreeding individuals
What are the two changes that occur during speciation
Divergence: species adapt to different environments
Reproductive isolation: species lose yeti ability to interbreed
What is allopatric speciation?
REPRODUCTIVE ISOLATION AD THEN DIVERGENCE, FORMATION IS GEOGRAPHICALLY SEPARATE
What is sympatric speciation?
Divergence leading to reproductive isolation, in same area
What is the biological species concept?
A species is a group of populations whose members have the potential to interbreed in nature and produce viable fertile offspring
When does allopatric speciation occur?
when population becomes geographically isolated and change in such a way they become reproductively isolated
What are the prezygotic barriers?
Impede mating or stops fertilisation habitat isolation Temporal isolation Behavioural isolation Mechanical isolation
What are post zygotic barriers?
Prevent hybrid zygote from developing into viable fertile adult
Reduced viability
Reduced fertility
Breakdown
What are hybrid zones?
WHEN ALLOPATRIC POPULATIONS COME BACK INTO CONTACT A hybrid zone can occur
What is sympatric speciation?
occurs in populations that live in the same geographic areas. is very rare
What is polyploidy?
a species may arise from accident during cell division that results in extra sets of chromosomes
