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Reversing Undesirable Fish Evolution
TaeKwonDood writes "Your granddad's approach to fishing — throw the little 'uns back — may have hurt their evolution, but we can reverse that, says a group of researchers, with a change of policy.
Fish have been 'reprogramming' themselves to be smaller and live longer. Welcome to evolutionary dynamics, Lamarck. But, no, they are serious. And it can be fixed within 12 generations. What do the smart people out there think about this? Are they using the term 'evolution' the wrong way?"
Of course not! Hollywood would be proud!
Oh, and they can get it down to 6 generations if they reroute the power from the main EPS conduits through the deflector dish in order to create a reversed polarity tachyon field. The tachyons will interact with the quantum state of the fish at a subatomic level, forcing them to grow larger. Sort of like inflating a balloon. With tachyons.
Are they using the term 'evolution' the wrong way?
Nope. It seems correct to this biology teacher. This is a clear case of directional selection. Keep eliminating the larger fish and the median size of fish in the population will be smaller. So, by taking the large ones, we are selecting against them and for smaller fish and juveniles. If, over time the frequencies of the alleles for large and small change in the population, then we have, by definition, evolution.
What makes you think this wouldn't be an example of evolution?
"Empathise with stupidity, and you're halfway to thinking like an idiot." - Iain M. Banks
Are they using the term 'evolution' the wrong way?"
If being smaller enables the fish to survive long enough to breed, then no. Big fish die off, small fish breed.
William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.
What does Lamarck have to do with it? These fish haven't been passing down traits they've developed during their lifetimes - we've been killing all the big fish, so smaller fish are selectively left to breed. That's Darwinian evolution.
In normal situations, I'd imagine that bigger fish tend to reproduce more often. But when some external force (e.g., thousands of fishers in boats with GPS and big nets) changes things, you get a different outcome.
If we preferred to eat fish that were darker in colour, they'd be getting lighter instead.
Either TaeKwonDood misunderstands evolution, or rushed to post his article a little too quickly...
---sheath
No, but you're being rather careless with your language.
It hasn't "hurt" their evolution. Their evolution has been helpful, based on the selection pressures they face.
Nor are the fish "reprogramming themselves". The species' genetic make up may be shifting (in a loose sense "reprogrammed") but they aren't doing it to themselves.
Boffoonery - downloadable Comedy Benefit for Bletchley Park
One species is trying to grow legs and arms so it can crawl to land and build nuclear weapons to end the world. We must stop this before it's too late!. -Anonymous Anomalocaris
Table-ized A.I.
Animal Husbandry has been doing it for years in one form or another.
See Wikipedia
Of course, if you leave the runts of the litter only, you end up with smaller critters. Its how many lap dogs were bred in the first place.
And like any breeder can tell you, of course it can be fixed in 12 animal generations!
Whenever I go out to the bars, I make it a point to take the smallest woman I can find home with me. It is my hope that within generations, the women remaining in the bars will all be larger and provide... um... ::analogy fail::
For years, the elephants in southern India have been hunted for their tusks. Fifteen years ago, you could very well run into a lone tusker in the wild with metre long tusks.
But now of late, there are baby elephants being born who grow up to be fertile males without the large tusks. With tiny foot long points out of their mouths, instead of something resembling the original giants that I used to love.
It's almost as if the poachers are even more of a significant selection force than nature and female preference put together.
Quidquid latine dictum sit, altum videtur
just because those fish didn't evolve the way we would have liked that it somehow means that it "hurt their evolution."
I'd in fact go further and say it has helped their evolution. If they become small enough that us humans cannot be bothered with them then they have managed to eliminate the most dangerous predator on the planet as a concern. Seems like a smart move to me.
... should read Beak of the Finch
Money is the root of all evil?
Technically they are correct, in practice I have my doubts. It is hard to get all the variables in a breeding programme to act in line. Ask any dog breeder.
I once was asked by someone from J. Witnesses if I could transform a human into a crocodile. Sure I said, just give me some 300 million years and I might succeed. And, give give me another 300 million years and I may even get it back to a human.
Me, the magician!
TFA describes a closed study of a population of fish. It's not an examination of wild populations of fish or an analysis of trends in wild populations. Extrapolating their observations from the closed population and applying them to the wild populations isn't accurate.
Commercial fishing is performed with nets (or longlines) and does not discriminate based on size. Everything in the net goes into the hold. Any non-target fish are discarded after they are dead. Sport fishing does discriminate based on size, but doesn't have a significant impact on saltwater fish. Also, larger fish are usually the smarter fish that have avoided anglers' lures, etc. which is a phenomena that isn't accounted for in this study.
Seth
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