Evidence of Evolution
Speciation: the formation of new species:
Speciation is essentially the process of "microevolution" (mainly through natural selection), typically over many generations, during which a new population of organisms accumulates sufficient genetic, physical, and/or behavioral changes that they can no longer mate and produce fertile offspring with members of the parent population. This new population is therefore considered as a new species. As this process continues over time, more and more new species may accumulate, and at some point they can all be considered collectively as a genus (category with two or more different species that are very similar, with evidence of relatively recent divergence into species). And so on, for the ever larger groupings in the hierarchy for classifying organisms. [See Microevolution to Microevolution presentation with diagram.]
Molecular Clues to Evolution
Macroevolution: Evolution on a Big Scale
Evidence for speciation
Observed Instances of Speciation
by Joseph BoxhornCopyright©1993-2004. [Last Update: September 1, 1995]
Evolution: Watching Speciation Occur | Observations (in Scientific American online - Science Sushi)
Evidence for Evolution
The Evolution List: Macroevolution: Examples and Evidence
8 Examples of Evolution in Action
Mistakes That Argue for Evolution
Why Evolution is True
15 Evolutionary Gems (pdf)
Examples of Evolution(Understanding Evolution)
Speciation in the Tragopogons (in the sunflower family):
Polyploidy in Tragopogon spp. by hybridization in the wild (in eastern Washington state):
Cross pollinatios between T. porrifolius (2n=12) and T. dubius (2n=12) produced the hybrid T. mirus (2n=24).
Cross pollination between T. dubius (2n=12) and T. pratensis (2n=12) produced the hybrid T. miscellus (2n=24).
Each hybrid is now self-propagating (as two new species), and neither can cross with its parent plants.
Polyploidy (doubling the chromosome numbers) happened in a single generation.