A challenge for evolution deniers: Explain why changes do not continue to add up over time

a reply to: Deaf Alien
What's thought of as microevolution occurs within a genus or species. This is the type that can be observed in a lab such as what barcs cited to be plausible evidence for macroevolution — which is evolution that occurs between genus, family and all the way up. Micro doesn't deal with the drastic morphological/physiological/behavioral changes that macro does. Macro can't be done in a lab of course so we must rely on the fossil record to piece together an evolutionary story.

The question essentially is asking: what prevents a four legged land dwelling insectivore from becoming a whale in 50 million years?

Or another question that can be asked is what will become of Lenski's fruit flies in another 100,000 generations? Is it plausible to think that with enough mutations we might bare witness to the formation of a completely different genera or family of insect?

a reply to: PhotonEffect

a reply to: PhotonEffect

I don't think Lenski ever did experiments on fruit flies but he worked on E. coli which is a evidence for evolution.

Is it plausible to think that with enough mutations we might bare witness to the formation of a completely different genera or family of insect?

Probably with enough number of generations.

How long it takes doesn't matter. Like the E. coli experiment it didn't take millions of years. 50,000 generations have passed over 25 years.

The question essentially is asking: what prevents a four legged land dwelling insectivore from becoming a whale in 50 million years?

Nothing. "Evolution deniers" are the one who made that claim.

a reply to: Deaf Alien

I don't think Lenski ever did experiments on fruit flies but he worked on E. coli which is a evidence for evolution.

You're right, he didn't. Late night post and it seems I was getting my experiments mixed up.

originally posted by: Chronogoblin
This thread, and every other one like it, are NOT about science, they are about back-slapping, and atheist rants.

Somebody didn't read the thread... I'm not sure why you'd post a blatant lie like that. I've specifically said multiple times to keep god / religion out of the thread. I know you can't resist taking shots at the evil atheists, but give it a rest.

IF you had an actual question, and you actually wanted a real answer, there are plenty of people on this site to give it to you.

So you can't answer the question. Good to know. Kindly step out of the thread instead of posting irrelevant off topic rants.

Virtually anything you could ask has invariably been asked before, and answered. Again, whether you accept the answers given, or not, is up to you.

Just stop. This question has been asked on this forum for years and nobody has EVER addressed or answered it. This is why I made a thread about it. It is the main cornerstone that the anti evolution crowd builds their foundation on. Originally they they denied evolution as a whole (including micro), but now they realize that it's so firmly proven in science that arguing against it is futile. So they create this false separation of micro and macro evolution, claiming micro can happen but macro is impossible. I'm asking them to explain why thousands or millions of small changes to an organism's genome cannot become large change.

a reply to: PhotonEffect

Most of what I'm about to say is intended for the thread as a whole, not just in direct response to you, so take it for what it's worth.

I think you demonstrated the primary misunderstanding in your response above where you said:

Micro doesn't deal with the drastic morphological/physiological/behavioral changes that macro does. Macro can't be done in a lab of course so we must rely on the fossil record to piece together an evolutionary story.

When you say "drastic" changes, it implies they are unrealistic, radical or sudden. That seems to imply that macro evolution is caused by big drastic events, but it only APPEARS that way when you look at the beginning and the end. Take a look at the common ancestor that humans and all of mammals share. Now compare it with humans, and it will appear to be night and day. It makes people go, "OMG, how can something that looks like a rat ever become an intelligent human?". The answer is really through 65 million years, which includes millions of generations, and tons of speciation events. There is never a single moment when it goes from rat to human. Looking at point A and Z and saying they are different is easy. What about A to B, or Y to Z? A to L? J to R? From A to Z is accumulation of speciation events, not a sudden drastic change from one to the other.

There is no micro or macro evolution. There is evolution. Micro and macro are simply about the amount of time involved. Micro evolution = speciation, macro evolution = the accumulation of numerous speciation events. Think about how many mutations there are per generation, then look at the total amount of genes in a genome. Humans have 3 billion base pairs of genes in their DNA. Each generation has roughly 150 genetic changes (based on research paper). So lets look at this logically and mathematically.

1 generation: 25 years, 150 genetic changes, only a tiny portion of the genome modified. No surprise that children look like their parents.

2 generations: 50 years, 300 genetic changes, still a small % of the genome is modified

10 generations: 250 years, 1500 genetic changes. Still not enough to be considered a big difference.

100 generations: 2500 years, 15,000 genetic changes. We're at .0005% of 3 billion genes changed

10,000 generations: 250,000 years, 1,500,000 genetic changes. This is close to the estimation of how long it took Homo sapiens to evolve from their prior ancestor. That is a .05% difference. Again, not huge, but still 1.5 million genes have mutated.

100,000 generations: 2,500,000 years, 15,000,000 genetic mutations. This is close to time frame of the entire homo genus. It is a .5% difference in DNA. Not a lot but enough.

Now we'll take it back to our common ancestor with chimps.

300,000 generations: 7,500,000 years, 45 million genetic changes: 1.5% of genome modified. This is very close to the amount of genes that humans and chimps do not have in common (usually between 1% and 1.2%)

Now the further we get from modern organisms, the harder it is to estimate because mutation rates can vary from species to species as well as individual to individual and we do not have data for organisms that old. The number of generations also varies per organism so it's near impossible to determine exactly, BUT for fun we'll run the numbers on this even though it will be inaccurate and will low ball the actual figure since 25 years per generation doesn't apply to most life on the planet. Most life reproduces within a year or 2 but we'll stick with these numbers for now.

3 billion years, about 150 million generations: 22.5 billion genetic changes. This is enough to rewrite the human DNA code from scratch 7+ times over, and that's a low ball estimate. No, I'm not suggesting these numbers are exact, because the generations change, the size of the genome has increased as well, so you'd expect less mutations on a small genome, but they do give you a rough idea of the concept of accumulation of genetic mutations over time. It shows that evolution is mathematically plausible. When genetic code is altered that much, big change is inevitable. Even if you ignore natural selection, a different genetic code is still a difference from the original, REGARDLESS of whether the mutations are neutral. It isn't about big sudden changes, it's about the change in genetic code over time. Many neutral mutations stay neutral until combined with others.

So basically, yes I'm saying that genetic mutations alone CAN be enough to lead to big change down the road. Obviously it's not the only factor involved, because the planet would get very crowded, but based on the math it's easily possible to acquire the necessary mutations to go from ancient apelike ancestor to modern human, or from single celled organism to mammals based on the percentage of genes that change over time.

a reply to: Barcs

When you say "drastic" changes, it implies they are unrealistic, radical or sudden. That seems to imply that macro evolution is caused by big drastic events, but it only APPEARS that way when you look at the beginning and the end.

Well, the cambrian explosion would meet that criteria. But really, that's besides the point. You bust my chops for nitpicking semantics and here you are doing the same with my use of the word "drastic". "Unrealistic" has never been the definition of drastic. So any implication you draw from my usage is of your own inclination. Not mine.

It isn't about big sudden changes, it's about the change in genetic code over time. Many neutral mutations stay neutral until combined with others.

In some cases, okay. But punctuated equilibrium says otherwise. Evolution doesn't require gradualism.

So basically, yes I'm saying that genetic mutations alone CAN be enough to lead to big change down the road. Obviously it's not the only factor involved, because the planet would get very crowded,

So in one sentence you say mutations alone are enough, then in the very next sentence you say it's not the only factor. That about sums it up then.

originally posted by: PhotonEffect
Well, the cambrian explosion would meet that criteria.

Would it really? 80 million years or so is considered sudden or radical?

In some cases, okay. But punctuated equilibrium says otherwise. Evolution doesn't require gradualism.

It's not required, but accumulation of genetic changes is. The speed is dictated by the environment, the genetic changes happen regardless. If you look at crocodiles, they haven't changed much in the last hundred million years. They got smaller along with a large amount of life on earth, but the genetic mutations still accumulated, even if they were mostly neutral. If you took the crocodile's ancestor from 100 million years ago or even 10 million years ago, it is very doubtful they could breed with the ones today despite looking similar. The reason for this is because the genetic mutations still happen, and still change the genome enough to make it incompatible.

So basically, yes I'm saying that genetic mutations alone CAN be enough to lead to big change down the road. Obviously it's not the only factor involved, because the planet would get very crowded,

So in one sentence you say mutations alone are enough, then in the very next sentence you say it's not the only factor. That about sums it up then.

I said they CAN BE enough, not that they are always enough in every case, or that there aren't other factors as well. My point was that the genes still mutate, and the mutations still accumulate, regardless of the other factors. Good thing it does, too, or its unlikely life on earth survives any of the extinction level events.

a reply to: Barcs

Would it really? 80 million years or so is considered sudden or radical?

Well, on a geological/evolutionary timescale, it's not a long time. Don't think about it anthropically.

Not to mention it's curious you would ask that question considering you're a gradualist.

[Gradualism is] not required, but accumulation of genetic changes is.

But your idea that accumulating mutations will cause speciation requires gradualism. That's the point. The two must go together. Now if you're going to agree that gradualism is not required for evolution, then you should also agree that neither are the accumulation of genetic mutations.

Also, would you mind citing the literature you've read that states accumulation of genetic mutations are an absolute requirement for evolution? I wonder if you might be confusing genetic variation with mutation. The former is a necessity for evolution to occur, but not necessarily so with the latter. The source of variation is not solely from mutations. It can also happen from recombination, genetic shuffling, and gene flow, to name a few. It should also be noted that germline mutations (vs somatic) are the ones that matter to evolution (since they are heritable), and a lot of times these are harmful.

You should also open your eyes to other mechanisms - non-mendelian inheritance patterns, genetic assimilation, epistasis and phenotypic/developmental plasticity. These have little or nothing to do with mutations yet still have a meaningful impact on evolution. But here's where you'll say this is off topic.

If you took the crocodile's ancestor from 100 million years ago or even 10 million years ago, it is very doubtful they could breed with the ones today despite looking similar. The reason for this is because the genetic mutations still happen, and still change the genome enough to make it incompatible.

Genetic mutations – that's it? How does this explain anything about why they couldn't breed?

My point was that the genes still mutate, and the mutations still accumulate, regardless of the other factors. Good thing it does, too, or its unlikely life on earth survives any of the extinction level events.

Sure, they accumulate. So what? Taken in isolation, which you insist on doing for some reason, what explanatory power does that have? Throw in natural selection? Okay fine – does that get us any closer to explaining evolution? No, it doesn't. There are a lot of other factors. And no one factor should be taken in isolation, no matter what point you're trying to make.

As this all relates to your narrow and superficial conception of how evolution works (at least in this thread) - it's not at all the linear relationship that your OP question requires. In isolating just the one aspect (accumulation of genetic mutations) of an entire process (evolution), you've left out much of the context that also matters. Which has been my beef this entire time.

I wonder, have you thought about the proportion of these mutations that occur in non-coding regions of the genome?

I'm done going back and forth on this. Our conversation is not conducive to the topic in the least. You don't even seem to understand my main point after all that explaining. I'm done explaining things. I'm tired of the philosophical traps. If you wish to argue against the genetic mutations accumulating, then present your case. If you cannot argue against this you are merely distracting from it. Mutations alone can be enough to cause speciation. That is the ONLY thing that matters. It's irrelevant that there are other causes. The mutations happen every time, and are involved in every species that changes over time. Sure, every now and then something else could cause a change, but I'm not talking about this. I'm talking specifically about the mutations accumulating, and what would prevent the level of change adding up or limit how much change an organism could experience given enough time. You have avoided this question like the plague.

Genetic mutations – that's it? How does this explain anything about why they couldn't breed?

Seriously? You feel that incompatible genes have nothing to do with ability to breed? Sorry I'm not seeing your position in the least and I'm tired of arguing things that have nothing to do with the topic. You conveniently ignored my entire part about genetic mutations per generation that clearly shows how they accumulate over time, changing the genome of the organism. There isn't anything else to say. Either you get it or you don't. If you don't, perhaps an evolution or genetics class should be in your future. If you do, then you are intentionally muddying the waters and distracting from my main point that has been shown in a lab.