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 ...
Global warming is a hoax
The Sun is going into a quiet period (The Solar Cycle) which will usher in a new mini Ice age.
But we won’t be able to post that this is bogus anymore as Obama is about to ruin and take over the Internet with heavy FCC regulation:
Americans aren’t even aware that the communist Obama is about to get the FCC to take over the Internet (Obama is taking over the Internet) with Soros socialist regulations
“(Soros strikes again!)FCC Cites Soros-Funded Marxist Group 46 Times in Regs (internet takeover) “
http://www.freerepublic.com/focus/bloggers/3267247/posts
I don’t recall reading of mass extinctions during the Medieval warming period. And somehow the people living on low lying land near the ocean managed to survive, too.
since the regime is cutting off coal, hyro electric dams, and nuclear electrical generation.....we looking at a short cold and brutal life ...
I guess King (Canute) Obama will issue an Executive Order to the Sun to correct the Sunspot deficiency.
Gee. Population genetics change with changing conditions...
I thought this was settled about a hundred years ago.
A couple of trillion bucks will set things right!
That grant study was evidently approved by the same democratic moron who approved the Field Mice move 200 yards of the hill to avoid global warming study.
The only good flea is a dead flea.
And the “scientists” assume that all the genetic differences between the samples are due to climate-change driven evolution.
There could be nothing else????
I don’t know where to begin tearing this down. (You can’t pick up the clean end of a turd.)
If their premise is true, there is no need to worry about Global Warming, is there? Because nature can adapt.
Burn the carbon at will, ensign!
SIR YES SIR!
Climate change is the rule rather than the exception. It is constantly changing regionally even while remaining generally stable globally. Genetic drift is one of the big movers of evolution. A population has many individual differences, some of which may be beneficial in a dry climate to the extent that more individuals with that variation survive and reproduce during a drought. The population as a whole will drift in that direction.
We’ve got climate change over short or long periods of time regionally in many parts of the world. Desertification in East Africa had its influence on human evolution.
Good point - I should have included human-generated CO2 driven climate change. (That is what the watermelons always infer with climate change, not natural transition or variation.)
As for population genetics and selection pressure, I am familiar with this topic. Selection pressure changes the frequency of alleles in the population. These alleles are all part of the species’ gene pool. It is hardly evolution. It, in no way, contributes to speciation.
You are not saying that small temperature changes or atmospheric humidity increases increase mutation frequency, are you?
Sickle cell anemia is a classic example of a mutation that changes frequency based on environment/selection pressure - it is beneficial in fighting malaria. - But Malaria did not cause the sickle cell allele to come into being. That thought is Lamarkian.
There is constant climate change without any consideration of human caused CO2. Climate is not static and has so many different influencing factors that models have so far failed. Ice columns drilled in Greenland give us a record of constant climate change over hundreds of thousands years.
Evolution is a fact, deal with it.
Evolution is theory, and is fairly robust, but very difficult to test and observe. There is no “settled science”in Science. It is all open to refinement, and incorporation of new observations. Only a non-scientist would make a claim that “this is Science fact” or “the Science is settled.”
Allele frequency change is not speciation (therefore not evolution), nor is it introduction of new genes into the species gene pool.
This selection pressure is all within the steady species state in Gould’s punctuated equilibrium model of evolution.
Amateurs chanting “evolution” don’t actually advance Science.
(On natural climate change, I’m fairly sure we agree completely.)
The specifics of evolution are constantly debated, debunked and revised but once the overall theory is contradicted by irrefutable evidence, it would cease to be a theory. However the evidence continues to accumulate. I don’t think there is a competing hypotheses with any observed support. The tripping point for most of us is to embrace the deep time necessary but that too as overwhelming factual support in geology, biology and physics. It’s a mind bender for a short lived person such as I to comprehend 100,000 years, let alone 4+ billion years.
Jim - The theory of gravity has been around about as long as evolution. There have been multitudes of advancements and refinements on the theory of gravity. Most of this is due to the comparatively easy experimentation on gravity vs. evolution.
Gravity, even though much more refined and tested than the theory of evolution, is still far from fully understood. Evolution, which is very hard to test experimentally, has many fine details ripe for scientific testing.
Gravity has never been thrown out, but it has been clarified hundreds of times, bringing the understanding down the subatomic level. Evolution does not need to be thrown out, but the understanding can be greatly refined.
In order to refine the theory - careful observation and reasoning must be put to work. These fleas, and their shifts in allele frequency, are not support for evolution.
Even though there is a good theory of evolution, this observation (the fleas) minimally supports, but does not advance the theory of evolution.
And neither Gravity nor Evolution are “settled science.”
PS - Yes, 4 billion years is a long time, but that is not evidence for evolution either. Oh, I happen to think that life will be found anywhere that liquid water exists over billion year time-frames, having studied Archaebacteria from black smokers, and bacteriophages.
3 or 4 billion years gives evolution time to work, if you will. Yes, there are recognized times when evolution is “explosive” and other time when status is the rule. These fleas are demonstrating a core means of evolution. A certain portion of the population increases in number in comparison the the past proportions. Eventually, most of the fleas have this characteristic. The characteristic was likely a benign mutation in numerous individuals over time. This specific change takes a short time. However such changes will mount up over time to become major differences with the original population. Major evolutionary change leaves a track in the fossil record.
It is always change within species (or kinds) but the cumulative product will be very different, a different but related species. All the while other animals and plants are changing, creating new environments which, in turn give nitches to be fill by changed other creatures. The most such nitches are, of course, found following mass extinctions. Then such events as the Cambrian explosion occur.
You just miss the distinction between intra-species variation and evolution.
Read Gould.
There is no smooth line in evolution. It is punctuated. That is the best current theory. These fleas are only demonstrating intra-species allele frequency change, perhaps due to climate change (perhaps due to something else).
There are no new alleles and the fleas did not evolve.
Can anyone see how extreme intellectual dishonesty is cleverly woven into this piece?
Intra species variations can over time lead to speciation. When an isolated sub population can no longer breed with the larger population, you have speciation by definition. While Gould advocated large surges of evolutionary activity following mass extinctions with stasis in between, he recognized genetic drift occurring when it gave a reproductive advantage. Many intraspecies variations are the result of copying errors (mutations).
Punctuated equilibrium takes time because change can be very fast in a geologic time scale and still take millions of years as in the 20 million year Cambrian Explosion.
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.