'Lifeless' prion proteins are 'capable of evolution' (BBC)

[eppur_se_muova]

Scientists have shown for the first time that "lifeless" prion proteins, devoid of all genetic material, can evolve just like higher forms of life.

The Scripps Research Institute in the US says the prions can change to suit their environment and go on to develop drug resistance.

Prions are associated with 20 different brain diseases in humans and animals.

The scientists say their work suggests new approaches might be necessary to develop therapies for these diseases.

In the study, published in the journal Science, the scientists transferred prion populations from brain cells to other cells in culture and observed the prions that adapted to the new cellular environment out-competed their brain-adapted counterparts.
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more: http://news.bbc.co.uk/2/hi/health/8435320.stm

[Chemisse]

1. They are so bizarre - it's hard to comprehend how they could do this - nt

[caraher]

2. Life is not a pre-requisite for evolving

Anytime you have something that replicates in some way and the ability to do so has an environmental component you have the potential for evolutionary processes to occur. Remember that there's no "agency" involved in evolution - it comes about through random processes, some of which result in useful adaptations, some of which don't. Whether or not something is technically a life form is beside the point; it's all about whether it reproduces in a way that can depend on random changes and is subject to environmental influences. So in a way perhaps it shouldn't be too surprising that prions can evolve.

[n2doc]

3. Absolutely amazing! n/t

[mike_c]

4. not surprising, really....

Computer code can evolve. Conceptually, anything that carries information about its own assembly or which-- as in the case of something like prions-- can affect the information about its own assembly, can respond to selective filters and change from one "generation" to the next, i.e. "offspring" can be better prepared to survive and reproduce than their progenitors were. That is evolution.

[azul]

5. Very confusing article. Hope people actually read up on prions to understand

the issue better. Though this information is not exactly easy to understand or forthcoming.

Prions are not an infectious "disease", they are just toxic proteins that cause a chemical poisoning "disease". A very curious and mysterious one, howsoever.

Prion proteins convert other similar proteins into a toxic, stable form by physically making contact, which then renders the protein nonfunctional in the cell so that the cell is stimulated to make more of the protein ("reproduction"). The prion converted proteins accumulate and eventually kill the cell, by physical disruption, and then the host if it is passed on to enough susceptible tissue.

I think "evolve" is misleading in that these toxins act mainly as catalysts to induce the production of more toxic proteins. It is a physical configuration chemical change, not a genetic one, and is better likened to a free-radical activation that is unquenchable.

They are observing the effects of various genetic differences in the different species proteins in various chemical conditions, not evolution as we define it.

It is not a bug.