A wonderful example illustrating how rapidly evolution can occur when changes in the environment caused existential selection pressures on populations of geckos and the changes that ensued.
http://www.sciencemag.org/news/2017/07/geckos-evolve-rapidly-brazil-afte...
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There's something strangely Lamarckian about all this. Except that instead of giraffes growing bigger necks to reach the treetops, its geckos growing bigger heads to eat bigger termites lol.
Nothing Lamarckian about this. The article did not state that a single geckos head grew larger as an adaptation to larger termites and then passed that adaptation onto its offspring. The mechanism would have been selection for larger heads. Those with larger heads outcompeting those smaller. The genes for larger heads then spread through the gene pool.
I don't know, the article leaves out a lot of information, and I'm too lazy to read the journal entry.
What happened to the food they were originally eating? It just said there was bigger bugs available cause the bigger geckos died. Like it makes it sound like these geckos just got greedy and wanted that caviar meal with gold flakes lol.
The reason I say it sounds Lamarckian is because this adaptation should have happened regardless of isolation. Whats keeping a mutation from making the heads of all geckos 4% bigger before the dam happened?
Nothing is keeping the heads at any size. The mutations are random.
I know, so the whole notion of the dams and the pockets of island is irrelevant. A 4% increase in head could have been observed anywhere, since its random. No dam need apply.
She looked there for Lamarckian reasons.
Error.
A species of moth in England had speckled black and white wings for camouflage against a background of tree bark. After the industrial revolution, soot and grime turned the trees black, and the moth's coloring turned almost completely black. Presumably the ones that weren't black were seen by birds and got eaten, while the black ones survived longer and had more offspring. Now the pollution has mostly gone, and moths are reverting to their original coloring.
http://www.telegraph.co.uk/news/earth/wildlife/5577724/Moth-turns-from-b...
Classic, but if I'm not mistaken, this is an example of natural selection at work, not evolution. Black and white moths were present in the population from the outset, just that the majority was white and minority black, then the roles reversed.
At least that's how I remember my bio textbook explaining it. One doesn't evolve into the other. One is selected over the other.
But there have to be non-standard (black) moths in a population of speckled moths for selection to occur. That's the mutation. A few would be born every generation and disappear because of their poor adaptation, until people turned all the trees black. That's how I remember evolutionary theory, though admittedly it's a long time since I've been in school.
John: "Classic, but if I'm not mistaken, this is an example of natural selection at work, not evolution. Black and white moths were present in the population from the outset, just that the majority was white and minority black, then the roles reversed.
At least that's how I remember my bio textbook explaining it. One doesn't evolve into the other. One is selected over the other."
Exactly! Evolution = Random mutation ..then...Natural selection.
That is what is so sad; John accepts mutation, and natural selection; but says evolution is impossible. It would be like believing there is such a thing as icecream and rootbeer; but saying rootbeer floats are impossible!
And with bugs it can happen quite quickly because of their short life spans.
I do understand how it works. But evolution didn't occur during the span of these observations, if a mutation did happen and presumably it did, it probably happened thousands of years ago. But at that point, what's the purpose of showing me this? Its not better than going out and killing all the white polar bears, and leaving all the black bear alive. Its natural selection, not evolution.
Nature selected the geckos with larger heads. That's a major part of evolution.
Mutations cause evolution, they're what change the species and "evolve" them. Natural selection kills the species, as is evidence by the death of the bigger geckos, who presumably also had bigger heads, and ate those termites just fine. NS does evolve anything.
Evolution clearly didn't have the termites in mind, since they could have easily grown 4% bigger as well. Seeing how termites reproduce faster than geckos, I don't see why not.
Another cartoon version emerges.
I wouldn't know, I'm too busy studying to watch cartoons. But I'll trust your experience.
Fascinating that they could adapt in a short amount of time.
Dinosaurs within 100 years!
According to this statement below the larger size food that was usually available to the larger lizards became available to those minions after the larger ones extincts. But the size of the mouth and the food create difficulty for the small mouth to take it. The question is what kind of food the little geckos ate while waiting for the mouth to grow larger? is the scientific paper presented mentioned the temporary eating method?
"The geckos had small heads—only 1 centimeter wide—and some of the termites were nearly the same size. Eating them presented a challenge, kind of like a house cat trying to put a squirrel in its mouth"
That's what I'm saying lol. It just sounds like they got greedy and tired of eating at Waffle House, so they upgraded so they could eat at a Michelin-starred restaurant.
Whales eat krill. There's no reason why their head had to grow so they can fit a bigger termite. Snakes head never grew to accommodate bigger food, why couldn't the geckos have evolved a snake-like jaw.
John
Why do whales have big mouths? The geckos evolved bigger heads to eat bigger prey.
Right, then shouldn't baleen whales evolve smaller heads, to eat the smaller prey?
Funny.
Simple. Baleen whale fossil shows origination of baleen. Large whales that eat small prey have to eat a lot of little things so big mouths help.
https://www.nature.com/articles/n-12286588
Just make smaller whales with smaller bodies and you don't have to eat so many.
The moment you try to rationalize things is when it sounds Lamarckian.
Just say these are the luckiest geckos and whales on the planet. And perhaps the luckiest researcher in the universe to have predicted randomness itself.
John : "Just make smaller whales with smaller bodies and you don't have to eat so many."
Who makes whales?
As it pertains to the conversation, evolution makes whales, not that difficult to follow.
There are large whales and smaller whale species. They share a common ancestor. They have evolved to eat a variety of food.
No they didn't evolve to eat a variety of foods. They just evolved. Whether they find food or not is their problem. Stahp it with the lamarckian exclamations.
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