Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
12 Cards in this Set
- Front
- Back
What are two models for the tempo of speciation? |
Gradualism and punctuated equilibrium model |
|
What is Macroevolution? |
Evolution of higher taca (e.g. different phyla or different classes, orders, families...) from speciation. A result of microevolution. |
|
What are types of reproductive mechanisms? |
Prezygotic and postzygotic |
|
What are different types of prezygotic reproductive mechanisms? |
Habitat, temporal, behavioral, mechanical, gametic |
|
What are some types of postzygotic reproductive mechanisms? |
reduced hybrid viability, reduced hybrid fertility, hybrid breakdown |
|
How can polyploidy cause reproductive isolation? |
Polyploidy results in instant sympatic speciation because when accidents happen during cell division and extra chromosomes result, offspring cannot reproduce with parent population anymore. = new species |
|
What are some examples of allopatric speciation? |
Harris antelop squirrel and white-tailed antelope squirrel |
|
What are some examples of sympatric speciation? |
May account for over 80% of plant species |
|
What is Mechanical Isolation? |
Structural differences in genitalia of flowers prevent copulation or pollen transfer (after mating) |
|
What is Gametic Isolation |
Female and male gametes fail to attract each other or are inviable (after mating) |
|
What is the punctuated equilibrium model? |
A new species changes most as it buds from a parent species (punctuated), followed by a period of stasis (equilibrium) |
|
Why does speciation occur after geographic isolation? |
Difference in gene pool potential for genetic drift, faced with different selection pressures |