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Ready, Steady, Evolve
Stront writes "New Scientist is reporting that plants and animals can 'bottle up' evolution until they need it. A certain protein 'hides away' mutated genes acting like a genetic valet, however in extreme environments, such as high temperature or noxious chemicals, the cleaning process breaks down and the mutations are released all at once. This goes some way to explaining examples that are considered to defy standard evolutionary theory, such as the Bombardier Beetle."
There's no great mystery; all of the chemicals are common, other beetles exist that excrete them separately; and the temperatures and pressures are not really that great (only just above boiling). So what?
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"You're confusing two different meanings of the word theory. One meaning is of hypothesis or conjecture, as in a suggested explanation yet to be proven right or wrong.
Another meaning is of governing principles as in "theory of operation". I have a book at home call "Loudspeakers: Theory and Design". The author does not offer hypotheses about how speakers work; he has no doubt as to whether they work and how they work. He's not writing conjecture - he's writing science and engineering - the general body of rules governing the operation of loudspeakers, which the author collectively refers to as their "theory of operation". This second sense of the word can be defied.
In the days of Darwin, the word "theory" in "Theory of Evolution" probably may have refered to the first sense of the word, as a hypothetical explanation of the origin of all species, including ours. But talk to a biologist or naturalist today and he'll tell you they have no doubt but that evolution is a fact; how it works, its principles of operation, is something they're still exploring and trying to explain.
This confusion between the meanings is something the Bible-thumbers love to exploit (I'm not lumping you in with them, though). They jump up and down and shout about how evolution is just a "theory" and that their half-baked Creation Science theories deserve equal consideration in the schools. Don't buy it. Evolution is a fact. We're sure of the big picture; it's just some of the details that we haven't worked out yet.
--Jim
And it's been a theory for a good twenty years at least in evolutionary biology. It explains why we find a lot of fossils of different species, but very few fossils that qualify as a "missing link" between species. This just gives a reasonable explanation for the mechanism which produces punctuated equilibrium.
Do not confuse duty with what other people expect of you; they are utterly different.Duty is a debt you owe to yourself.
I'm doing the traditional /. thing and not actually reading the article, but I assume it's the old news on heat-shock and chaperone proteins being shown to be a general case.
This isn't "saving up" mutations. This is a system for supressing aberrant mutations breaking down in stressful environments. The True Believers out there would like to phrase this to illustrate the cleverness of natural selection, but this is the failure of a beneficial system leading to a honking buttload of mutants appearing. Nothing more. Yes, throwing a bunch of random solutions at the problem may find an answer and allow a population to continue living in a stressful environment, but it's a bit assuming to try to say the system has evolved to break down in this manner (though it is a rather elegant failure mode).
As for the bombardier beetle...
Hydroquinone and hydrogen peroxide, when mixed, turn brown over the course of a couple minutes and won't taste very good. Various beetles besides the Bombardier Beetle use the chemicals, uncatalyzed, merely for the foul taste. Evolution can work in as many steps as it likes increasing the foulness of the taste without any delightful imagery of exploding beetles occurring to anyone.
Of course the page linked to is slow to abandon such delightful imagery so, while it is kind enough to mention that nothing very exciting happens unless you add a catalyst, it likes to give the impression that without that catalyst (or "anti-inhibitor", if you please) the beetles would die a horrible death in the manner of a piece of popcorn, though not quite as tasty.
Let me let you in on another "secret". There can be huge ranges of activity in classes of closely related proteins. This is especially true of the enzymes responsible for catalyzing naturally occuring reactions between simple chemicals. This is a bit of a problem for the Creationist because their idea of the beetles stumbling across a highly efficient enzyme and blowing themselves to bits for generations is very useful. Having them stumble across a weak version that merely made them taste a little worse than their competitors when an attacker mixed the chemicals together is hardly an exciting idea. Nor is it exciting for this weak enzyme to follow the same path of increasing the foulness of the taste that the parahydroxybenzene glands went through.
Of course, once this enzyme reaches a certain level it does get to be dangerous to the beetles. Chance encounters with learning predators that may have only have caused injury become fatal due to the beetles' own defense mechanism (though, because the added foulness of taste deters predation, this is still beneficial to the species, though not to the individual). Any solution is beneficial, as the alternative is death. The apparent winner is to excrete the chemicals, which isn't surprising as some of the other Brachinus species do this without the fun of superheating. Coevolution of improvements to the catalyst and to the ejection system gives us what we have today.
Unfortunately, answering one set of Creationists' call to provide an explanation is met with catcalls of "just-so-story!" from another set. It's really best to ignore them as a group... which, hey, is what I'll be doing.
Simple Machines in Higher Dimensions
Every so often, a biological/evolutionary/ecological topic comes up on Slashdot. Now, folks here are mostly engineers of one sort or another, not biologists, and it shows.
:-) As someone who has way more than dabbled in both fields, I can say that a hard engineering mindset does not lend itself to understanding the biological sciences in general, and ecology/evolution in particular.
I have an MS in ecology and population genetics, but have also made my living in the CS field for years (to pay the mortgage, you understand
Evolution (and I've taught college courses on the subject) is not engineering. To understand it, you need to understand ecology, genetics, biochemistry, lots of general biology, etc., etc. There are few topics with more misunderstandings, by people who think they understand it all, and don't. Including some people in the field, har har.
Finally, regarding the Creationists and the "irreducible complexity" thing. As the Theory of Evolution got traction in the intellectual world, the Creationists always pointed out something we didn't understand as proof of a Creator. As more and more became understood, they retreated to the next thing. This was called the "God of the gaps" approach - if we don't understand NOW what's going on, it must be GOD!
That's how I feel about "irreducible complexity". It will be found to be reducible. Well, maybe, mabye not. Where is it written that talking monkeys should necessarily come to understand the Cosmos in all its glory? That's what we are, boys and girls. For all our wonderful accumulated knowledge, there's an infinite ocean of subtlety out there... there's no guarantee that it's all accessible to our brand of cognition or any other computation either.
We return you now to your regularly scheduled trollfest...