In Reply to: one of many examples of evolution in action posted by moonshiner on July 20, 2005 at 18:09:07:
This is a known event: variation within a species. Look at all the kinds of dogs. A species is a species if they can interbreed and produce fertile young.
The definition of a species is NOT, as this scientist (trying to coin a new definition) says:
"Because warblers choose mates based on song patterns, these two groups do not mate. 'If two groups do not exchange genes through reproduction, they are on separate evolutionary pathways and therefore they are separate species,' Irwin says."
Irwin is mistaken and that was some leap of logic to make that statement. If the two warblers CAN mate and produce fertile young, they are still one species -- whether they choose to or not.
Many races of, or variations of, humans consistently choose not to cross racial/social or other lines to mate, yet we're still one species.