A: Microevoltuion is the changes in a singel gene pool where as macroevoltion deals with patterns of evolutionary change over long periods of time.
Q: What is a species?
A: A species is a kind of organism.
Q: How does environment affect evolution?
A: Evolution is affected by environment because in some cases a population may be secluded from outside contact.
Five main facts:
1) Reproductive barriers keep species separate.
2) In allopatric speciation, geographic isolation leads to speciation.
3) Reproductive barriers may evolve as a population diverges.
4) Most plant species trace their origin to polyploid speciation.
5) Hybrid sones provide opportunities to study reproductive isolation.
This diagram shows polyploid speciation. Polyploid speciation is where organisms with more then two sets of homologuous chromosomes are able to breed.
Chapter 14 focuses on how species have evolved over time. This is partially due to natural selection but other variables are present. Speciation allows for new species to diversify. Reproductive barriers have also lead to a very diverse set of species because only certain organisms are able to breed together. Environment also affects how species have evolved over time.
Key Terms:
1) Taxonomy: branch of biolgy that names and classifies species
2) biological species concept: primary definition for species
3) Reproductive isolation: prevents genetic exchange and maintains the gap between species
4) Reproductive barrier: biological feature of the organism itself
5) Prezygotic barriers: prevent mating or fertilization between species
6) Postzygotic barriers: operate after hybrid zygotes are formed
7) Allopatric speciation: initial block of gene flow due to geographic barrier
8) Sympatric speciation: new speices that arise within the same geographic area as a parent species
9) Polyploid: cells have more then two complete sets of chromosomes
10) Adaptive radiation: evolution of many diverse species from a common ancestor
http://www.youtube.com/watch?v=YCoEiLOV8jc
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