House Dust Mite Study Shows Reverse Evolution Possible

[Eugene]

Source: Nature World News

House Dust Mite Study Shows Reverse Evolution Possible

By Staff Reporter | Mar 09, 2013 05:32 AM EST

A new study shows that certain organisms can undergo reverse evolution, that is, go back to the way they were living before evolving new traits. The study challenges the idea that evolution is uni-directional and an organism can't undo changes.

The idea that organisms can't revert back is held by Dollo's law, which states "that evolution is not reversible; i.e., structures or functions discarded during the course of evolution do not reappear in a given line of organisms. The hypothesis was first advanced by a historian, Edgar Quinet."

The present study was conducted by a research team led by two biologists from University of Michigan who conducted the study on common house mites that live on mattresses, sofas and carpets. These mites have evolved from parasites that have in turn come from free-living microbes.

"All our analyses conclusively demonstrated that house dust mites have abandoned a parasitic lifestyle, secondarily becoming free-living, and then speciated in several habitats, including human habitations," according to Pavel Klimov and Barry OConnor of the U-M Department of Ecology and Evolutionary Biology.

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Read more: http://www.natureworldnews.com/articles/781/20130309/house-dust-mite-study-shows-reverse-evolution-possible.htm

[LiberalEsto]

1. I'm afraid the Tea Party beat them to it. nt

[Geoff R. Casavant]

2. I thought with the demonstrated many years ago.

For example, whales and dolphins evolved from land mammals, and got their fins and flippers back.

[htuttle]

5. I don't think I'd call that reverse evolution either

The only thing fish fins and dolphin fins have in common is their function -- to propel themselves through the water. Otherwise, they have no structural resemblance at all.

[jehop61]

3. Oh sorry,

I thought you were talking about Mitt devolution

[htuttle]

4. It's a stretch to call that reverse evolution

It seems more like the mites adapted to a new environment -- couches and carpeting instead of dogs and cats and birds.

[Viva_La_Revolution]

6. that's my reaction too!

maybe they re-evolved cause they realized being a parasite sucks. Humans should be so lucky to realize the same.

[muriel_volestrangler]

7. If you read the actual press release, they came via nests

Nature World News missed that bit.

How might the ecological shift from parasite to free-living state have occurred?

There is little doubt that early free-living dust mites were nest inhabitants—the nests of birds and mammals are the principal habitat of all modern free-living species in the family Pyroglyphidae. Klimov and OConnor propose that a combination of several characteristics of their parasitic ancestors played an important role in allowing them to abandon permanent parasitism: tolerance of low humidity, development of powerful digestive enzymes that allowed them to feed on skin and keratinous (containing the protein keratin, which is found in human hair and fingernails) materials, and low host specificity with frequent shifts to unrelated hosts.

These features, which occur in almost all parasitic mites, were likely important precursors that enabled mite populations to thrive in host nests despite low humidity and scarce, low-quality food resources, according to Klimov and OConnor. For example, powerful enzymes allowed these mites to consume hard-to-digest feather and skin flakes composed of keratin.

With the advent of human civilization, nest-inhabiting pyroglyphids could have shifted to human dwellings from the nests of birds and rodents living in or around human homes. Once the mites moved indoors, the potent digestive enzymes and other immune-response-triggering molecules they carry made them a major source of human allergies.

http://www.eurekalert.org/pub_releases/2013-03/uom-gso030613.php

[Neoma]

9. You'd think they'd know that from looking at Pidgeons.

[MyshkinCommaPrince]

10. How is it a reversal?

I am admittedly undereducated, so I may be making some simple error of thought, but I don't see how this is "reverse" evolution. Isn't it just bog-standard evolutionary adaptation to changing conditions? That previously rejected traits are now recurring doesn't seem like it's necessarily a reversal. It seems like a framing error to present the idea as some kind of backtracking. It's being discussed in the frame which holds that evolution always moves "forward", meaning toward more and more "advanced" characteristics. With humanity being the metric for "advanced". Placing us at the top of a pyramid. Perhaps I am babbling toward the anthropic principle?

Dammit, I need to read more science, or Carl Sagan's ghost is going to come back and smack me around some day....

[Warren DeMontague]

11. Are we not men?