Archive for the ‘Speciation’ Category

Disintegration II

Secession? (plus)

Why not take it all the way to speciation?

(I can already see it’s going to be hard to keep up.)

November 12, 2016admin 42 Comments »
FILED UNDER :Speciation

Quote note (#280)

Bacteria are often invoked as agents of ‘rhizomatic’ (horizontal) disruption of tree-like genetic lineages, so it’s intriguing to see them being proposed (p. 161-2) as cladistic engineers:

If two groups of the same insect ignore each other and only mate with their social circles, they should eventually split into distinct species. These splits occur all the time in nature, and the forces that cause them can take many forms. They could be physical obstacles like mountains or rivers. They could be differences in timing, in the hours or season in which animals are active. They could be incompatible genes that prevent two animals from interbreeding. Anything that stops animals from mating, or that kills or weakens the offspring of those couplings, can create ‘reproductive isolation’ — a gulf that drives species apart. And as [Eugene] Rosenberg had shown, bacteria can cause reproductive isolation, too. By acting as a living barrier that stops two populations from meeting up, microbes could potentially drive the origin of new species. …

September 4, 2016admin 76 Comments »
FILED UNDER :Speciation