the selection process || Flashcards
(20 cards)
What is the main challenge in understanding species?
To understand how all these species originated.
What are the two types of evolutionary change?
- Cladogenesis (macro evolution)
- Anagenesis (micro evolution)
What is a biological species?
A group of organisms that can reproduce with one another in nature and produce fertile offspring.
How did humans acquire pubic lice?
Humans transmit pubic lice through sexual contact; they originated from gorillas ~ 3 million years ago.
What percentage of DNA do non-Africans share with Neanderthals?
Around 3%.
What factors are necessary for successful reproduction?
- Right place
- Right behaviour
- Right time
- Physically possible
- Genetically possible
What are the two types of speciation based on geography?
- Allopatric speciation (geographically isolated areas)
- Sympatric speciation (same area)
What is allopatric speciation?
Speciation that occurs due to geographic isolation.
What causes genetic isolation in allopatric speciation?
Populations diverge to the point where they no longer interbreed due to adaptation or genetic drift.
What is an example of geographic isolation?
Two species of antelope squirrels isolated by the Grand Canyon.
What is a founder event speciation?
A speciation event that occurs when a small group of individuals colonizes a new area.
What is host-parasite cospeciation?
A scenario where host and parasite species evolve in tandem.
What is sympatric speciation?
Speciation that occurs without geographic isolation, often through genetic isolation.
What is autopolyploidy?
A condition where meiosis fails, resulting in an organism that cannot breed with its parent due to chromosome mismatch.
What is allopolyploidy and its significance?
A form of polyploidy important in crop evolution, such as wheat.
What is an example of hybridization in animals?
Gray tree frogs where tetraploid Hyla versicolor resulted from hybridization.
What is the apple maggot fly’s significance in speciation?
Matings between hawthorn and apple flies have reduced to ~6%, leading to their classification as incipient species.
Is the speciation of cichlid fish in African lakes sympatric or allopatric?
It can be both; habitat preference and sexual selection drive sympatric speciation, while lake level changes suggest allopatric speciation.
What is the relationship between speciation and evolutionary change?
Speciation can occur in allopatry or sympatry, with two kinds of evolutionary change: anagenesis and cladogenesis.
How is sympatric speciation more common in plants than animals?
Due to mechanisms like allo- and autoploidy.
