Evolution Flashcards
What is evolution
The changes in organisms over generations as a result of genomic variations.
What is natural selection
The non random increase in frequency of DNA sequences that increase the chance of survival.
What happens in stabilising selection
An average phenotype is selected for. And extremes of the phenotype are selected against.
What happens in directional selection
One extreme of the phenotype range is selected for
What happens in disruptive selection
Two or more phenotypes are selected for creating distinct groups.
What is horizontal gene transfer?
Where genes are transferred between individuals in the same generation.
What is vertical gene transfer
Where genes are transferred from parent to offspring as a result of ASEXUAL OR SEXUAL reproduction.
Is natural selection more rapid in eukaryotes or prokaryotes?
Prokaryotes
What is speciation
The generation of a new biological species by evolution in a result of isolation, mutation and selection.
What is meant by the term species
A group of organisms that is capable of interbreeding to produce fertile offspring.
Role of geographical barriers
Prevents gene flow between sub populations during speciation.
What speciation does geographical barriers lead to
Allopatric
What speciation does behavioural and ecological barriers lead to
Sympatric
