Posted on 05/11/2015 11:26:54 AM PDT by Oldeconomybuyer
The water flea has genetically adapted to climate change. Biologists from KU Leuven, Belgium, compared 'resurrected' water fleas—hatched from 40-year-old eggs—with more recent specimens. The project was coordinated by Professor Luc De Keester from the Laboratory of Aquatic Ecology, Evolution and Conservation.
The water flea Daphnia is a zooplankton organism that is typically found in shallow ponds and lakes. Under normal circumstances, water fleas reproduce asexually: they clone themselves. But in difficult living conditions - during food shortages or heat waves, for instance - they switch to a different type of procreation: they mate and lay dormant eggs.
As the dormant eggs remain viable for a long time researchers can use resurrection ecology to examine the evolution of water fleas in a changing climate. Biologist Aurora Sqeerts explains: "When water fleas reproduce asexually, their offspring is genetically identical to the mother. But when they mate, this results in genetic variation. The genetically fittest water fleas - the ones that are best adapted to the environment - survive and lay dormant eggs. When we hatch the dormant eggs of water fleas from the past and compare them with the contemporary population, we can reconstruct the evolutionary changes that occurred in that population and examine how they have adapted to the rising temperature of the water in which they live."
The capacity for genetic adaption is, however, not enough to guarantee success, Sqeerts adds: "Climate change may have an impact on other factors as well. The water flea might be exposed to more enemies, less food, or an increased sensitivity to parasites. But our results show that we need to take into account the evolutionary dynamics of a species if we want to predict how it will respond to climate change."
(Excerpt) Read more at phys.org ...
“When an isolated sub population can no longer breed with the larger population, you have speciation by definition. “- js
Not exactly - Different species have actual differences in genetics and behavior.
If I seperate out a colony of white rats, and prevent them from interbreeding with any other rats, have I created a new species? Simply no.
-And without further mutation, they will *always* be the same species of rat as the original, and be capable of interbreeding.
What can I do to end this?
Ok, I figured it out.
You win - Man made global warming made the fleas evolve. You and the good professor should report to Stockholm to collect your Nobel prizes.
:-)
The ability to breed successfully, producing fertile offspring is an essential definition of species. A finch will always produce a finch but over generations, one population of finch may no longer successfully breed with another. Horses and burros are close relatives but different species with the mule offspring only very rarely being fertile.
BTW there are several separate “rat” species.
You win - Man made global warming made the fleas evolve. You and the good professor should report to Stockholm to collect your Nobel prizes.
:-)
BTW - horses and burrows have different numbers of chromosomes, a *huge* genetic difference.
but -
You win - Man made global warming made the fleas evolve. You and the good professor should report to Stockholm to collect your Nobel prizes.
:-)
Thank you for the prize. BTW I’ve not said a thing about man made global warming which remains in question but there are constant climate changes. El Niño, when the current is so configured does produce climate changes in adjacent land areas. I not aware that it is man caused.
BTW chimps and humans have different numbers of chromosomes as well although we share a distant relative with them about seven million years ago. It seems that somewhere along the way two chromosomes which apes have became fused together in humans with no loss in functionality.
“It seems that somewhere along the way two chromosomes which apes have became fused together in humans with no loss in functionality.” - JS
Really, now is that history, or the scientific method that leads you to that little gem?
oh - never mind.
Biology 101.
So, you are saying there is this massive chromosomal mutation punctuating the evolution from chimp to human.
Yea for you. You finally get it. Genetic drift didn’t do it. Allele frequency changes do not mark the differences. Massive chromosomal change marks the difference.
1. Humans and chimps share a common ancestor. Humans have not evolved from chimps.
It is not necessary to use the pejorative “massive” when the combination of chromosomes doesn’t result in the loss of function or information.
ok - have a nice day!
We're not supposed to notice the assumption of temperature (and, further, global warming) related causation of any observed changes...
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.