I get the whole micro-evolution stuff where creatures breed to improve the species, but we've been breeding fruit flies for a long time and ended up with more fruit flies and not some kind of mutant superfly whose genetic structure is different than the others. (Aside: With whom would such a freak breed to produce viable offspring when its genetic structure wouldn't match its mate's?)
In any case, what hit me was how tied the guy was to Darwinian evolution. He couldn't allow even a single disagreement or objection. It had to be true, nay, it was true and anyone who didn't dogmatically agree was an infidel. As a Catholic, I don't really care one way or another. Recall that we believe that God doesn't make contradictions and that if established science conflicts with theology then theology must change. Science doesn't bother me at all, but miracles or intelligent design don't bother me, either.
So in all innocence, I brought up those objections - how do structural genetic changes occur resulting in fruit flies eventually producing sheep? He went bonkers and threw all manner of snarky, you're-an-ignorant-moron meme images at me.
I hope he had fun doing it. Me, I idly wandered off and had a Firestone Union Jack and watched the Cubs game.
Follow Up: Here's a UC Berkeley bit on the evolution of flight, but it begs the question at hand. I can see how flying is better than not-flying, but I don't see the process at the molecular level. Where did all those atoms come from in the modified genetic codes? Why did the reactions happen instead of producing death and deformity?
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| Lots of people dream about flying like a bird. Do lots of birds dream about driving Buicks like a person? |
16 comments:
No one dreams of driving a Buick. It's a Buick. That is a nightmare.
We had an assistant Pastor years ago that was talking about evolution. His summation, "Oh, so that's how he did it."
"How do you get from the genetic structure of a fruit fly to that of a sheep through random processes?"
You don't, because there is too much that you'd have to undo to switch from the insect body plan to the mammal body plan. But then, that is very different from what anybody thinks happened[1]. Instead, both are derived from scratch from an organism more like a worm, with some of its descendants developing one set of characteristics (like an exoskeleton and jointed legs), while other descendants developed different characteristics (like an internal skeleton and a backbone).
"we've been breeding fruit flies for a long time"
Not really. Fruit flies have only been used as model breeding organisms since about 1888, when Charles Woodworth championed using them as model organisms. This might seem like a long time to a human, but compared to even a single million years it is a merest fleeting nothing[2]. And as for why we haven't developed a whole slew of new fruit fly species, remember that that is not what people are breeding them for. They are breeding them to study how their genetics work as they are, not with the intent of making them into something else.
As far as getting new species in general, in my years looking at insects I've realized that the whole "species" concept is much more fluid and loosely defined than we are often lead to think. You get a different species when one group *doesn't* interbreed with another group, but that is not the same as saying that they *can't*. You get groups of, say, mayflies that are different species because they emerge on different days, or crickets that don't interbreed because their females are attracted to different songs, or any number of other little things like that, but if the divergence was less than a few tens of thousands of generations ago they could still be crossed with each other if someone made the effort to force them somehow.
Just look at your little dogs, and contemplate the wolves that they were derived from (in just a few hundred generations, no less). Sure, they *could* be bred with wolves, but left to themselves they most likely *wouldn't*, if only because the wolves would probably just eat them. If we saw chihuahua mixes in the wild, and wolves in the wild, without the intermediate dogs, then we never would have classed them as the same species.
[1] If this statement is actually from the book you are listening to, it is a red flag that he is not arguing in good faith. It shows that the author is pretty much ignorant of what evolutionary theory actually says, and is making stuff up.
[2] It is really easy to forget that what seems to a human to be a long time, is practically no time at all as far as the earth is concerned. Anything under a million years is considered a short time for evolution to occur, and a transformation that takes only a thousand years is practically the same as instantaneous. Meanwhile we are looking at right around seven hundred *million* years since the common ancestor of a fruit fly and a sheep. That is, to put it very mildly, a mind-bogglingly huge amount of time.
There are a few examples of blended yet distinct species around today. They are called 'ring species'. For a clear description see http://www.actionbioscience.org/evolution/irwin.html My bad description is that you have a species, as you move in some direction you see the species subtlety change (always interbreedable) until after moving far enough you now have members that cannot bred with those at the start. That is, you have two separate species but with continuous examples of "intermediate" species. That is how evolution happens.
Even understanding that It is still somewhat mind bending to think about the fact that most changes will lead to death and deformity, yet given the incredible length of time enough neutral and beneficial changes have come up to produce the overwhelming bio-diversity we have.
I can see how micro-evolution might lead to macro-evolution over time. And you should understand that if a creature fits a niche well, they really have no pressure to evolve (i.e. crocodiles). There are problems with creatures that have symbiotic relationships. It's hard to see how those would come about. But the real problem as I see it, is the chicken/egg issue of the first functional organism and its DNA. A functional organism needs genetic material to reproduce and regulate growth and maintenance. Did a complex chain of deoxyribonucleic acid just happen to string itself together in just the right order to produce a functional cell? I can't see how that would happen.
I think I'm with Ivyan on this. I get the whole "zillions of years of breeding" large numbers argument, but I'm not sure it's relevant. Wait as long as you want and you'll never see an apple fall up.
Again, I'm not arguing for one side or another, I'd just like to see the chemical equations by which the structural changes happened and be given a reasonable source for the reactants. Wouldn't the modification have to happen at conception? If that's the case, it would seem to bound the problem quite nicely allowing for a contained set of variables and a solvable chemical equation.
It's amazing the lengths to which people will go to not see Darwinism for the fraud it is.
KT: I'm looking at your last comment, and trying to figure out what it is that you think is going on during biological development of an organism. What do you mean by "chemical equations by which the structural changes happened"? It sounds like you think that a living thing develops the same way that reactions happen in nonliving processes, where you mix together particular chemicals, maybe with a particular catalyst, and they bulk-react to make a particular product. I agree that if life worked like that, then evolution would make no sense because the same reactants would always make the same products.
The thing is, life does *not* work like that. Sure, you start with a set of reactants, but the products you get depends entirely on the DNA code, which controls the myriad of separate processes by which everything is put together. That's why you might have two carnivorous animals that both eat slugs and worms, but one turns the reactants into more shrews while the other turns the same inputs into more beetles. It is that code that evolves, not the reactants.
I think that most of your questions about evolution are actually questions about "how does DNA control growth and development", which really is a distinct question from "how does evolution happen". Maybe you could look into that, I think that you'd find it pretty interesting.
^ What you're saying is that 'evolution' isn't a science.
Ilion, that makes even less sense than your usual non-sequitors.
Boo-hoo.
Ohioan-- there's some slight of hand in the "ring species" reasoning that got me quite peeved when I first figured it out...I think it was with the Spotted vs Barred owl, but it may have been wolves/coyotes/red wolves.
If you check your links wording, it says that they seldom interbreed, and thus are different species. It's not that they are so genetically different that you can breed A to B, B to C, and C to D, but not D to A, it's that it "rarely" happens-- in the case that got me looking more closely, they were having fits because it turned out that two "different" species interbred just fine-- it simply didn't happen in the wild because of distance between the main populations. There weren't even any behavioral differences in some of the examples! I use to have a link to a quite official document stating that "coydogs"-- coyote/dog hybrids-- were clearly urban legends, since they were different species and "couldn't" interbreed. This wasn't even an obscure view, I found coydogs classed with cabbits all the time in 'oh those dumb country people' type books.
(They seldom interbreed, for the same reason that bobcats and domestic cats seldom interbreed-- the wild ones will eat the domestics, unless one's a female in heat.)
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This is kinda related to the argument going on right now about if animal "families" should be grouped by theoretical genetic similarity, or by objective features placed into theoretical "families."
Besides the whole problem of getting DNA for, oh, dinosaurs-- a lot of the "species" groups we have were identified by "there is a true-breeding population of animals with characteristics that are different from the true-breeding population of animals in that area over there.
I think that's how the "red wolves are genetically just wolves with a LOT of coyote in them" discovery was made.
*Everything* Darwinism touches becomes polluted by slight of hand "reasoning".
Tim I agree completely with this: "The thing is, life does *not* work like that. Sure, you start with a set of reactants, but the products you get depends entirely on the DNA code, which controls the myriad of separate processes by which everything is put together."
My problem is that those DNA codes have to come from somewhere and obey laws of chemistry to react in a new way. My problem is that when mommy and daddy fruit fly love each other very much and make whoopee, the resulting fertilized egg's DNA can only come from the DNA in the sperm and the egg. If it's going to have a new number of branches / atoms / chromosomes / whatever, those atoms had to come from somewhere and have a reason to combine in a revolutionary way and not kill the resulting baby.
Follow-up post here. I'll take your answer off the air. ;-)
Ilion, I'm not sure of any of it and I'm certainly not willing to make a blanket statement about Darwinism. Lots of people much smarter and more knowledgeable than me have done a lot of work on the topic. You got to show them some respect even if they're mistaken. They certainly work hard at it and most of them in good faith.
No, they don't; and, no, I don't.
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