Guppies are small fresh-water fish that biologists have studied for long.
Posted on 06/11/2009 11:19:01 AM PDT by Pharmboy
Guppies are small fresh-water fish that biologists have studied for long.
UC Riverside-led study shows wild Trinidadian guppies adapted in less than 30 generations to a new environment
RIVERSIDE, Calif. – How fast can evolution take place? In just a few years, according to a new study on guppies led by UC Riverside's Swanne Gordon, a graduate student in biology.
Gordon and her colleagues studied guppies — small fresh-water fish biologists have studied for long — from the Yarra River, Trinidad. They introduced the guppies into the nearby Damier River, in a section above a barrier waterfall that excluded all predators. The guppies and their descendents also colonized the lower portion of the stream, below the barrier waterfall, that contained natural predators.
Eight years later (less than 30 guppy generations), the researchers found that the guppies in the low-predation environment above the barrier waterfall had adapted to their new environment by producing larger and fewer offspring with each reproductive cycle. No such adaptation was seen in the guppies that colonized the high-predation environment below the barrier waterfall.
"High-predation females invest more resources into current reproduction because a high rate of mortality, driven by predators, means these females may not get another chance to reproduce," explained Gordon, who works in the lab of David Reznick, a professor of biology. "Low-predation females, on the other hand, produce larger embryos because the larger babies are more competitive in the resource-limited environments typical of low-predation sites. Moreover, low-predation females produce fewer embryos not only because they have larger embryos but also because they invest fewer resources in current reproduction."
Study results appear in the July issue of The American Naturalist.
Natural guppy populations can be divided into two basic types. High-predation populations are usually found in the downstream reaches of rivers, where they coexist with predatory fishes that have strong effects on guppy demographics. Low-predation populations are typically found in upstream tributaries above barrier waterfalls, where strong predatory fishes are absent. Researchers have found that this broad contrast in predation regime has driven the evolution of many adaptive differences between the two guppy types in color, morphology, behavior, and life history.
Gordon's research team performed a second experiment to measure how well adapted to survival the new population of guppies were. To this end, they introduced two new sets of guppies, one from a portion of the Yarra River that contained predators and one from a predator-free tributary to the Yarra River into the high-and low-predation environments in the Damier River.
They found that the resident, locally adapted guppies were significantly more likely to survive a four-week time period than the guppies from the two sites on the Yarra River. This was especially true for juveniles. The adapted population of juveniles showed a 54-59 percent increase in survival rate compared to their counterparts from the newly introduced group.
"This shows that adaptive change can improve survival rates after fewer than ten years in a new environment," Gordon said. "It shows, too, that evolution might sometimes influence population dynamics in the face of environmental change."
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She was joined in the study by Reznick and Michael Bryant of UCR; Michael Kinnison and Dylan Weese of the University of Maine, Orono; Katja Räsänen of the Swiss Federal Institute of Technology, Zurich, and the Swiss Federal Institute of Aquatic Science and Technology, Dübendorf; and Nathan Miller and Andrew Hendry of McGill University, Canada.
Financial support for the study was provided by the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, the Le Fonds Québécois de la Recherche sur la Nature et les Technologies, the Swedish Research Council, the Maine Agricultural and Forestry Experiment Station, and McGill University.
The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 17,000 is expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion. To learn more, visit www.ucr.edu or call (951) UCR-NEWS.
There is no reason why a sufficient number of adaptations like this couldn’t lead to speciation. It would take a long time to observe (except in the case of microbes) but its possible.
This is evolution at work. It is not about creating a new creature, but a more environment oriented species. The fact the female lays less eggs, and has larger babies is an evolution of the DNA that controls the production of eggs. Its a clear change to respond to the environment surrounding it.
Adaptation, on the other hand, doesn't involve changing the basic DNA of a creature, but also works in the circumstances surrounding it. For example: During seasons of heavy snows and lots of moisture, deer have a tendency to have 2-3 foals, during high periods of drought, they tend to have 1 or none.
Amen!
Provide evidence guppies can change into, say, frogs in 10 years and I'll get excited about evolution. Until then ...
Now, that’s impressive (and depressive all at the same time).
The two examples given here are different exactly how????? I call BS.
Isn’t it amazing how quickly God’s creatures can adapt to their surroundings? Look how fast these fish were able to adapt, and yet fish remain fish from the moment they first appear in the fossil record until now. This is dramatic confirmation that A) Darwinian evolution through random mutations plus natural selection is a crock and B) it is dramatic confirmation that each animal was designed to adapt quickly within the boundaries of each created kind.
All the best—GGG
Eight years later (less than 30 guppy generations), the researchers found that the guppies in the low-predation environment above the barrier waterfall had adapted to their new environment by producing larger and fewer offspring with each reproductive cycle. No such adaptation was seen in the guppies that colonized the high-predation environment below the barrier waterfall.
So, the article uses the term Adaptation - where's the fire?
The guppies are still the same old lovable buppies all of us tortured for our first animal experiments.
Just pinged the list above. Thanks for the heads-up!
Not really. There are different species of fish around these days, and they go where we allow them to go. That doesn’t turn us into God.
> Evolution is defined as genetic change over time,
> sometimes leading to new species, sometimes sub-species,
> sometimes breeds or races.
The definition of Evolution itself evolves to fit into whatever circumstance its proponents wish.
Neat.
Subject to change without notice.
Just like the small print in the slick sales literature.
When I was in school, they taught that Evolution meant that non-living material magically organized itself into enzymes and proteins, which magically organized themselves into RNA and DNA which then evoved into one-celled creatures which in turn changed into vastly more complex plants and animals and eventually even to man, in tiny steps over hundreds of millions of years.
Nobody explained how the same catalytic processes that were said to cause non-living molecules to so assemble themselves would not also destroy them, or where the new genetic code for the new functionalities and features of newly evolved creatures came from. Nobody explained how features that are not fully formed and would actually hinder a creature’s chances of survival could persist for thousands of generations before finally becoming useful.
Neo-Darwinists were so daunted by the logical challenges presented by such a paradigm, as well as the challenges presented by the fossil record, that they devised “Punctuated Equilibrium” and “Hopeful Monster” scenarios, both just as incredible and silly as the original Darwinist position.
What does the “hopeful monster” breed with, unless there is another “hopeful monster” with the same mutation in the same location close enough to the same time to provide a mate?
It takes a lot more faith to believe in such superstitions as it does to believe simply that God Created.
Clearly this is the missing link to more public junk science grants...
You could take these same two groups of guppies and reverse their environmental conditions and in the same amount of time see the exact same changes.
Their genome hasn’t changed, merely the expression of it due to environmental conditions.
You could in fact produce the exact same results in your own home aquarium set up. In the end you’d still just have guppies with the same old guppy genome.
“Evolution can occur in less than 10 years”
eah...just look at how your 401k has evolved.
Steve Jones, on page 170 of “Darwin’s Ghoxt,” writes;
“Within a species, in different places selection may call for (or be offered) different mixtures of mutations to do its job and may come up with subtly different products. Quite often, one local blend does not combine well with others. Sometimes - as in the two inherited errors that jointly cause the smoky gray fur of the Persian cat - the nature of interaction is known, but more often it is not. If the failure of adapted mixtures to work together becomes complete, the populations find it impossible to exchange genes when they meet, and each becomes, in effect, a new species.”
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