Dr.GH
Posts: 2333
Joined: May 2002
|
Splurty has spamed this list of questions all over the intertubes. He merely ignor replies, or engages warp 7 goalposts.
in responce to spurtstuf's question #1
| Quote | "Island Biogeography of Populations: An Introduced Species Transforms Survival Patterns"
Thomas W. Schoener, Jonathan B. Losos, David A. Spiller
Science 16 December 2005: Vol. 310. no. 5755, pp. 1807 - 1809
Population phenomena, which provide much of the underlying basis for the theoretical structure of island biogeography, have received little direct study. We determined a key population trait—survival—in the Bahamian lizard Anolis sagrei on islands with an experimentally introduced predatory lizard and on neighboring unmanipulated islands. On unmanipulated islands, survival declined with several variables, most notably vegetation height: The island with the shortest vegetation had nearly the highest survival recorded for any lizard. On islands with the introduced predator, which forages mostly on the ground, A. sagrei shifted to taller vegetation; unlike on unmanipulated islands, its survival was very low on islands with the shortest vegetation but was higher on the others. Thus, species introduction radically changed a resident species' relation of survival to a key island-biogeographical variable. |
There is also;
| Quote | "Evolutionary Biology: Catching Lizards in the Act of Adapting"
Virgina Morrell
Science 2 May 1997:
Vol. 276. no. 5313, pp. 682 - 683
Twenty years ago, evolutionary biologists transplanted small populations of Anolis sagrei lizards from Staniel Cay in the Bahamas to several nearby tiny islands, all of which had been lizard-free. The researchers expected the reptiles to go extinct, but by 10 to 14 years later, the animals appeared to be undergoing the kind of body changes that in time could turn each island's population into a separate species. If the changes are genetic, the study would be strong evidence that isolated populations diverge by natural selection, not by genetic drift, as some theorists have argued. |
Which was a discussion of :
| Quote | "Natural selection out on a limb"
Ted J. Case
Nature 387, 15 - 16 (01 May 1997)
and
"Adaptive differentiation following experimental island colonization in Anolis lizards"
Jonathan B. Losos, Kenneth I. Warheitt, Thomas W. Schoener
Nature 387, 70 - 73 (01 May 1997)
If colonizing populations are displaced into an environment that is often very different from that of their source1, they are particularly likely to diverge evolutionarily, the more so because they are usually small and thus likely to change by genetic restructuring or drift2,3. Despite its fundamental importance, the consequence of colonization for traits of founding populations have primarily been surmised from static present-day distributions1,2,4,5, laboratory experiments6 and the outcomes of haphazard human introductions, rather than from replicated field experiments. Here we report long-term results of just such an experimental study. Populations of the lizard Anolis sagrei, introduced onto small islands from a nearby source, differentiated from each other rapidly over a 10–14-year period. The more different the recipient island's vegetation from that of the source, the greater the magnitude of differentiation. Further, the direction of differentiation followed an expectation based on the evolutionary diversification of insular Anolis over its entire geographic range. In addition to providing a glimpse of adaptive dynamics in one of the most extensive generic radiations on earth, the results lend support to the general argument that environment determines the evolution of morphology. |
--------------
"Science is the horse that pulls the cart of philosophy."
L. Susskind, 2004 "SMOLIN VS. SUSSKIND: THE ANTHROPIC PRINCIPLE"
|
