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[edit] Summary
Geographic illustration of SPATIAL ASPECTS OF SPECIATION:
- allopatric speciation - physical barrier divides population
- peripatric speciation - small founding population enters isolated niche
- parapatric speciation - new niche found adjacent to original one
- sympatric speciation - speciation occurs without physical separation
Drawn in Inkscape by Ilmari Karonen, based on en:Image:Speciation modes.png and http://www.bio.miami.edu/dana/160/speciation.jpg from http://www.bio.miami.edu/dana/160/160S04_6.html
Adapted from: Spring 2006, Lecture Notes for EVOLUTION AND BIODIVERSITY class (BIL 160 Section HJ) by Dr. Dana Krempels, dana at miami dot edu.
- Might need some overhaul.
- For one thing, it is rarely a "niche" but a geographic range. Except in en:heteropatric speciation where it is always a niche of some sort (microhabitat, reproductive season etc), but otherwise the same as in sympatric speciation (which in the strict sense requires chance reproductive incompatibility, and except for en:Wolbachia-mediated evolution such cases are rare).
- Also, the time between the third and fourth stage is almost always much longer (an order of magnitude) than the entire time the stages 1-3 take. Because except in cases where coevolution is a "driver" of the speciation process - say, a herbivore or nectarivore adapting to a new host plant -, the newly-arisen species will be ecologically very much alike and thus can hardly coexist. Before they can again become sympatric in their distribution (as in stage 4), one or both need to diverge significantly. And that takes time... a lot of time usually. Say a few millions of years, if the entire speciation process takes a few 100.000 years. Until then, you have (except in sympatric/heteropatric speciation) en:superspecies where the individual members do not occur together in any one place.
- -- dymorodrepanis
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