U1 KA7 Evolution Flashcards
What is evolution?
The changes in organisms over generations as a result of genomic variations.
Define natural selection.
The non-random increase in frequency of DNA sequences that increase survival and the non-random reduction in the frequency of deleterious sequences.
What are the types of selection that affect phenotype frequency?
Stabilising, directional, and disruptive selection.
Is natural selection more rapid in prokaryotes or eukaryotes?
Prokaryotes.
Why is natural selection more rapid in prokaryotes?
Prokaryotes can exchange genetic material horizontally, resulting in faster evolutionary change than in organisms that only use vertical transfer.
What is speciation?
The generation of new biological species by evolution as a result of isolation, mutation, and natural selection.
What is the role of isolation barriers in speciation?
They prevent gene flow between sub-populations during speciation.
What type of speciation occurs due to geographical barriers?
Allopatric speciation.
What type of speciation is caused by behavioral or ecological barriers?
Sympatric speciation.
