This is an excellent experiment
and it demonstrates a lot of what we have surmised. The shortening taking place needs to be
noticed because there is go evidence here of the selection been affected by
predation at all. Again the lizards
understand shorter is better and their genetic code allows for just that
modification so it begins to appear. In
the same way, all humanity is entering a world of food abundance and the perceived
advantage goes to the full sized version of humanity. Thus we are watching population enlarge
before our own eyes in the expanding urban environment.
The new version of mankind will
have men at a ‘normal’ six to six and a half foot in height and massing in
their prime at a trim two hundred pounds.
Not enough to take on Big Foot but certainly twice the mass of his great
- great - grandfather. Certainly good
nutrition in one’s primary growing period and no heavy work load is a contributor
but not sufficient to explain the broad generational enlargement. It simply takes at least three generations of
encouraging living conditions to accomplish this result.
It is a little surprising but I do
not think that in humanity that a small stature is a genetic imperative. The evidence shows us that every population
seems to become larger approaching a similar size distribution.
'Founder effect' observed for first time
by Staff Writers
Washington (UPI) Feb 17, 2012
Biologists have observed a theory of species evolution known as the
founder effect in action for the first time, U.S.
The founder effect, first outlined by German evolutionary biologist
Ernst Mayr in 1942, says that when a small group of individuals from a
genetically diverse population of some species migrates away and
"founds" a new colony, the founders' genes play a dominant
evolutionary role in the new population for generation after generation.
Biologists, including scientists who did postdoctoral work the
University of California
They visited heavily forested Iron Cay, a Bahamas island spared the
ravages of 2004's Hurricane Frances, and took brown anole lizard couples from the island at
random to seven tiny treeless islands nearby where no lizards remained after
the Category 4 hurricane.
On each island they released a single lizard pair, they said.
The Iron Cay lizards long ago evolved long hind legs to run swiftly
along broad tree branches to avoid predators, the researchers reported.
But on the seven islands slammed by Frances, the anole lizards that
drowned had short hind legs, better suited for darting in and out of the short,
tangled, scrubby bushes that thrived there, the San Francisco Chronicle
reported, citing the researchers.
If the founder effect held up, succeeding generations of the
transplanted lizards would maintain their long hind legs, even though the
original lizard residents had short legs, the researchers postulated.
The researchers returned to the islands every year to observe and
measure the legs on each new generation of lizards, which now populate the
islands.
After five or six generations, the founder effect appeared to hold up,
with the new generations still sporting the long hind legs of their ancestors,
the scientists reported.
But they saw another evolutionary force emerge, they said.
The lizards' long legs began shortening as each generation adapted
to the scrub-bush environment, they said.
The scientists realized they were also witnessing Charles Darwin's natural
selection, a key mechanism
of evolution, they said.
"In this case, we've seen both the founder effect and natural
selection operating right before our eyes -- for the first time," Jason
Kolbe, a postdoctoral fellow at U.C. Berkeley and U.C. Davis and now at the
University of Rhode Island, wrote in the American Association for the
Advancement of Science journal Science Express.
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