Is Evolution Predictable?

An anonymous reader writes "C|Net is carrying a story about some research out of Rice University. They are exploring the possibility that we can predict the evolution of a species, given environmental factors." From the article: "Typically, the bacteria can continue to thrive when the temperature hits 73 degrees Celsius (163 degrees Fahrenheit). The experimental strain of bacteria contained a mutated version of a gene that, in the naturally occurring strain of the microbe, produces a protein that made existence possible. They then put these mutant strains in environments where the temperature rose slowly but steadily, and studied how different generations coped with the changing temperature. In the breeding that followed, millions of new mutations of the gene in question were produced, but only about 700 of those variants replicated some of the functionality of the naturally occurring gene."

He's from spain

[Joris Van Damme]

I had to read this several times before it started making sense... It's encrypted, really, it is.

> The experimental strain of bacteria contained a mutated version of
> a gene that, in the naturally occurring strain of the microbe,
> produces a protein that made existence possible.

That should read:

The experimental strain of bacteria contained a mutated version of a gene that, in the naturally occurring strain of that gene, produces a protein that made existence in these temperatures possible.

So, in short, they disabled the microbes heat resistence, and saw if the buggers could grow it back.

Re:So it almost seems evolution follows a... desig

[Anonymous Coward]

Bah. Strongly biased anti-intellectual rant. Nothing to see here.

Re:Evolution isn't just adapting to environment

[vertinox]

You have got to be kidding. To even have a BASIC understanding of evolution you have to know that it means species evolve to fit new environments.

Actually it isn't just that... (Well if you include evolving because other species are eating you, but that could be lumped into 'environment')

It is that mutations are random and often times ill suited for their environment, but it is only a matter of chance that something survives to pass on its genes. Whether it is not being eaten into extinction by another species, not over populating until you destroy existing resources and then you go extinct, not dying because of an ice age, or not being wiped out by a meteor.

One can say... Well that was the environment that killed off those species... Well it isn't because that the species evolved to adapt to the environment, but only those whose random mutations made them more suited for the environment survived.

As in... If you put a million grizzly bear in the polar region none of them are going to spontaneously evolve his fur white more like a polar bear because that was the best choice.

However, if any of those bears happened to spontaneously mutate into where their hair turned white making them better hunters so that the seals couldn't see them. Then those species may actually do better than there brown counterparts and may survive in times of hardship where as the browns die out.

What I am trying to say is that any mutation that doesn't kill off the species will continue in the species, but it is more probable that mutations that allow a species to survive will get passed on.

Take our appendix for example... What the hell does that do?

It may or may not have had some purpose in the past, but we simply don't evolve it away because it doesn't kill us so we pass it on to the next generation.

Basically, evolution isn't about mutating into the best possible creature for the environment, but rather we mutate constantly and the mutations that kill us don't get passed on.

Now that leads to the question "What really causes DNA mutations?"

Chances are it could be do to higher radiation events during magnetic pole reversals or gamma ray bursts where the radiation is so high that many species die of cancer and health problems, but those who do survive have random mutations. After that... Any mutation that doesn't kill the species off due to environmental factors passes those genes on.

Re:So it almost seems evolution follows a... desig

[gm0e]

Hey bud, copy and paste much?

http://www.worldmag.com/articles/11485 [worldmag.com]

All I had to do was copy and paste one phrase into google with quotes.

Re:Yes

[anarchyboy]

you're 3 orders of magnitude out! thats pretty bad

Re:Evolution isn't just adapting to environment

[plunge]

One theory on the appendix has been that the smaller the appendix comes, the MORE likely it is to get infected and kill. So once evolved, and once run out of a useful purpose, it has become very hard to get rid of, because many of the avenues are blocked.

Likewise, it's worth noting that very often disparate elements are linked. The appendix itself might not be a good thing, but it's developmentally linked to or even just very close to something on the genome that is hard or dangerous to tinker with. And thus, it has been left alone since tinkering with that area of the genome breaks something else important.

Re:Evolution isn't just adapting to environment

[kirkjobsluder]

Now that leads to the question "What really causes DNA mutations?"

Chances are it could be do to higher radiation events during magnetic pole reversals or gamma ray bursts where the radiation is so high that many species die of cancer and health problems, but those who do survive have random mutations. After that... Any mutation that doesn't kill the species off due to environmental factors passes those genes on.

Not bad up until this point.

For one thing, most evolution has less to do with mutations, and more to do with subtle variations between members of a species. So with the case of fur color in mammals, you have multiple genes that contribute to the quantity of melanin in hair. Individuals with combinations ideally suited to the environment are more successful than others.

Secondly, we know many of the actions for how mutations happen at the biochemical level. Most mutations occur because of errors in DNA replication and repair. Another class of mutations occurs because DNA can fold back on its self under certain conditions, or become attached to other strands. These mutations occur all the time and with a frequency stable enough that we can use them as timers to estimate the geologic time that has elapsed since Kodiak bears and Polar bears shared a common ancestor.

How about the Hawaiian islands then?

[yankpop]

And if they used a more realistic environment and got results that weren't so clear, then people would argue that they should have done something simpler where they could control all the variables. The answer is to use both approaches, but not necessarily in the same study.

There was an interesting paper on that touched on the same issues using a 'natural experiment'. They looked at a group of spiders that colonized the Hawaiian islands. Each island contains a collection of the same ecotypes of these spiders, but they all have different histories. If only one spider species colonized an island, evolution lead to it forming several different species to fill the basic ecotypes. If two or more spiders colonized the island, they divied up the ecotypes. So what you get was species 1 splitting into three species to match ecotypes A,B, and C on one island. On another island species 1 evolved to fill ecotype C, and other species 2 filled in A and B. And on another island species 2 had evolved to fill all three ecotypes.

In a nutshell, the evolutionary pattern was repeated over and over, with the same ecotypes arising from different ancestors. It didn't matter which species you started with, you always got the same product. This agrees with evolutionary theory, but I don't think you would expect such consistent results in an uncontrolled environment.

If you're interested in the details, it's Gillespie et al in Science 16 January 2004:Vol. 303. no. 5656, pp. 356 - 359

yp.

Re:Kidding, right?

[geekboy642]

One variant, called Q199R, appeared almost immediately, and the bacteria that contained it became the dominant strain of bacteria through 500 generations of breeding. The gene, however, couldn't provide protection after 62 degrees Celsius.

At that point, five new strains of bacteria, all with slightly different versions of Q199R, appeared. Three of the five new strains were driven to extinction in a few days, while the remaining two fought it out for three weeks longer.

The group then conducted the experiment again, and the same mutations developed . Thus, the experiment suggests that evolutionary development can be predicted, the researchers said.

Hey moron, can you READ?!?