olsen@ll-xn.ARPA (Jim Olsen) (05/23/86)
In article <7730@glacier.ARPA>, bhayes@glacier.ARPA (Barry Hayes) writes: > ... the division of organisms into species is fundamental, representing > the genetic barrier of producing fertile offspring. > > But one thing that has always troubled me is the arising of a new > species from an old. ... What could do it other than two or more > simultaneous identically placed mutations? So what gives? > How does it happen? Has it ever been observed to happen? Speciation needn't be an instantaneous process. Consider an isolated group of individuals of a certain species. Genetic changes can occur and spread through the group, so that the group can interbreed. When the cumulative changes are such that the group can no longer interbreed with the original species, speciation has occurred and the group forms a new species. -- Jim Olsen ARPA:olsen@ll-xn UUCP:{decvax,lll-crg,seismo}!ll-xn!olsen
evans@mhuxt.UUCP (crandall) (05/24/86)
It's been years (6) since my various evolution and ecology courses, but at
that time speciation had been observed and documented in a few insects living
in areas with recently imposed barriers.
Sukie Crandall