SPECIATION Flashcards
What are the 3 species concepts? And what is the key to all of these Concepts of species?
- Morphological (typological) Species
- Biological Species
- Lineage Species Concept
-Key is REPRODUCTIVE ISOLATION
What are the limitations and key ideas behind: Morphological (typological) species concept?
Type Specimen (all characteristics looking for in that organism) Ex: Natural History Museum.
LIMITATIONS: Might not have type specimen & Lots of variation between species (characteristics)
What are the limitations and key ideas behind: Biological Species Concept?
(Not perfect answer)
(Earnest Mayr)
A species is a population or group of populations whose members have the potential to interbreed with one another in nature to produce FERTILE offspring, but who cannot successfully interbreed with members of other species.
LIMITATIONS: time and things that don’t sexually reproduce/interbreed with one another (ex:bacteria)
What are the limitations and key ideas behind: Lineage Species Concept?
Species are branches on a “tree of Life”
How do gene incompatibility and chromosome incompatibility contribute to reproductive isolation?
inability to exchange genes
What is the main difference between allopatric speciation and sympatric speciation?
- Allopatric speciation occurs when a population is separated by a geographical barrier,
- Sympatric speciation occurs when subset populations cannot be separated by a geographical barrier.
Describe a scenario that illustrates Allopatric speciation:
Chipmunks on either side of the Grand Canyon
Describe a scenario that illustrates Sympatric speciation:
Apple Maggot Fly, Europeans introduced new tree that bloomed sooner than the fly’s normal tree, and overtime the population that remained on the original tree was a different species because of the ones on the new tree.
Why is sympatric speciation by polyploidy less common in animal species than in plant species?
It is rare in animals, making polyploids is almost impossible (they end up with hybrids)
What are prezygotic reproductive barriers?
-Habitat Isolation
-Temporal Isolation
-Behavioral Isolation
(IF ALL IS RIGHT THERE IS A MATING ATTEMPT)
What are postzygotic reproductive barriers?
- Reduced Hybrid Viability
- Reduced Hybrid Fertility
- Hybrid Breakdown
Example of Prezygotic reproductive barriers:
______
Example of Postzypotic reproductive barriers:
______
What happens if the hybrids are Just as fit as the parent species? Describe a scenario that illustratesas the parent species, what is the outcome for the hybrids and the parents?
mixed gene pools, fusion into one species. Non-assortative mating.
What happens if the hybrids are LESS fit as the parent species? Describe a scenario that illustrates as the parent species, what is the outcome for the hybrids and the parents?
reinforcement of gene pool/ reproductive isolation
-Horse and Donkey
