science tumbled

(selections: pretty pics / longer stories)
This guy is an Italian Wall Lizard, Podarcis sicula. This species gained media attention in 2008 as an example of rapid macroevolution. In 1971, five females and five males were moved from the tiny island Pod Kopište to the even tinier island Pod Mrčaru, both in the Croatian Adriatic. When researchers returned in the mid-2000s, the insect-eating, territorial lizards had turned into veggie-munching hippies. Well. To be more precise, their diet had consisted of only 4-7% plant material on Pod Kopište, but on Pod Mrčaru, this varied seasonally between 34 and 61%. In changing their diet, population density went up, and the lizards gave up defending territories. In addition, their heads had become larger and changed shape; they had evolved harder bites, in order to chew tough plant material; and finally, the pièce de résistance: they had evolved cecal valves. These valves slow down the passage of food through the system, creating fermentation chambers. In these chambers, microbes not usually found in P. sicula break down the otherwise undigestible cellulose.
All this in approximately 30 generations.

This guy is an Italian Wall Lizard, Podarcis sicula. This species gained media attention in 2008 as an example of rapid macroevolution. In 1971, five females and five males were moved from the tiny island Pod Kopište to the even tinier island Pod Mrčaru, both in the Croatian Adriatic. When researchers returned in the mid-2000s, the insect-eating, territorial lizards had turned into veggie-munching hippies. Well. To be more precise, their diet had consisted of only 4-7% plant material on Pod Kopište, but on Pod Mrčaru, this varied seasonally between 34 and 61%. In changing their diet, population density went up, and the lizards gave up defending territories. In addition, their heads had become larger and changed shape; they had evolved harder bites, in order to chew tough plant material; and finally, the pièce de résistance: they had evolved cecal valves. These valves slow down the passage of food through the system, creating fermentation chambers. In these chambers, microbes not usually found in P. sicula break down the otherwise undigestible cellulose.

All this in approximately 30 generations.