I can’t speak for cetacean genomes (since I don’t think we have good quality cetacean genomes yet), but this issue is easily addressed for hominins by looking at present-day human and chimpanzee genomes. This was the point I was making (so very long ago) when I said the changes are small.
Compare the human and chimpanzee genomes. There are no differences between them that are not easily in reach of standard evolutionary processes within the time allotted.
If you dispute this point, please point out any genetic differences that you think are not accessible to standard processes. The human and chimpanzee genomes are freely available online.
Sir, thanks as always for the gracious reply. I certainly don’t discount the observation that the number of mutations are theoretically of such a number that, given mutation rates, arriving at a human genome is a theoretical mathematical possibility in the time allotted, should every necessary mutation that leads down a pathway to human intellect and abilities fortuitously show up just when needed. I wouldn’t doubt the same is theoretically possible within cetaceans. But these are not my sources of skepticism.
Nor do I dispute that any particular difference could be consistent with and explicable by the evolutionary process.
Please consider an illustration: I could claim that this response I’m writing to you was actually generated in approximately one hour by a random character generator: I started with a completely random string of 2600 characters, and then had the computer randomly change one character at a time, cross checked against a dictionary that would keep any such changes that got closer to English words.
I could equally observe that the changes are very small (only 2,600 characters) compared to the differences between chimps and humans (60,000,000), and if you compare the original random characters and this response, there are no differences between them that are not easily in reach of my random character mutation /dictionary process within the time allotted, given processing speed.
And if someone expressed skepticism, I could also just as easily answer, “If you dispute this point, please point out any digital differences that you think are not accessible to my random letter generator processes.” And admittedly, there would not be a single difference between my original set of completely random characters and this reply that, in isolation, could not be explained by random character substitution.
Thus I could equally claim that this response I’m posting to you was “easily obtainable” by my random character generation within the timeframe allotted. But if I were making that claim seriously, you would be quite in your rights to say that I was not accounting for all the intentional thought and purpose that goes into writing a few coherent and purposeful paragraphs.
I don’t in the least mean to suggest any direct analogy between my illustration and evolutionary process. I only mean to show why the very true and accurate observations you noted (that the raw numbers are theoretically within reach of the process, and that no one particular mutation is inconsistent with the process), do not in themselves address or assuage my skepticism.
First, I think a better analogy is moving from state “A” (prokaryotes) to state “Q2hyaXN0b3BoZXIgSm9obiBGYWx0ZXIgLSBmb2xsb3dlciBvZiBDaHJpc3QsIGh1c2JhbmQsIGZhdGhlciwgZGF0YSBzY2llbnRpc3Q=” (me). That’s encoded in base-64, BTW, in case you want to decode it. Bottom line: There are at least a bazillion and one states between prokaryotes and me.
Second: the state machine is extremely stochastic. It generates billions of new states every second – every time a cell replicates. (Hence the bazillion and one steps in the previous paragraph.) Some of those steps result in a loss of information, and some result in a gain of information. If natural selection on balance gives preference to new states that result in a gain of information, then new information can indeed appear.
Third: One of the basic insights of Shannon information theory is that information and energy are proportionate. You cannot create information out of thin air; it requires an investment of energy. In the presence of a continuous net energy inputs, however, information gain can occur.
So…is there some source of continuous energy input to the Earth’s biosphere that could have facilitated an information increase over the course of billions of years? Give it some thought and tell me what you think.
Yours,
Chris
P.S. - Have you ever seen video of Ben Underwood, who uses echolocation to ride his bike, navigate obstacle-strewn sidewalks, stairs, etc.?
I learned long ago that it’s not my job to convince people that evolution is true - my job is to make the evidence as accessible as possible so people can make up their own minds.
Consider Behe, who has said things like unless he is given evidence for every single mutation, and the frequencies and fitnesses within the population for each, for each generation, and so on… that he will doubt evolutionary processes. Science has no way to deal with that level of skepticism.
Of course, with that kind of skepticism, we’d never convict anyone of murder either.
So, that said, I don’t expect you to become convinced either. That’s ok. Most of the time I write for those that are looking on in any case.
Your analogy breaks down on a few levels. The first one that comes to mind is that you’re postulating a situation going from complete randomness to non-randomness. That’s not realistic. The last common ancestor of humans and chimpanzees would have been a very complex organism, with lots of biological information present. We’re talking about evolution shaping that starting point in two distinct ways, with the results remaining over 95% identical.
It’s also worth pointing out (as I think I have before, or perhaps @glipsnort did?) that meaningful differences are a small fraction of the raw differences. The actual changes that make a difference are far fewer than the raw differences.
More could be said, but there’s work to be done. Maybe others will chime in.
Perhaps you could ask yourself why you are so skeptical about evolution - do you think that you’re coming to this with a clean slate? Could it be possible that your prior commitments are hindering your ability to look at the evidence dispassionately? Are you familiar (and forgive me, I can’t remember) with the myriad evidences for the reality of common ancestry for humans and chimps? If so, are you trying to find something that “can’t be explained” within that reality? Or do you doubt common ancestry altogether?
I could make the analogy more similar by comparing two very similar computer programs… take those text adventures I used to play back in the 80s, as I’m familiar with their code, I played “Ghost Town” and “Pyramid of Doom”, for instance. Their code is probably around 95% similar, the core structure, input, output sequences, are all identical. The only significant differences is their internal mapping, description of objects, and description of locations. I could try a similar thought experiment wherein I claimed to change one to the other by random word changes, only in the vocabulary section, tested by a Grammer corrector… and again the number of changes could conceivably fit into certain time constraints, and no particular change would be inherently inconsistent with my “random word substitution” theory. But still the idea of getting such a coherent plot from such a method would be rightly unbelievable. But no analogy is perfect, of course.
I don’t know the specific fraction to consider, but If we’re talking about even 1/1000 changes being meaningful or necessary to rewiring our brains and bodies for the unique and staggering nags functions we can do, that is still 150,000 changes that must be right. But this isn’t really the core of my doubt.
I don’t particularly go one way or the other in regard to common ancestry. There seem to be significant overlaps and evidence of vestigial or inherited or damaged genes. As such I’m open to considering the hypothesis that there were 5million years and that modern humans are so descended (as Bebe embraces, if I understand correctly.)
I also am open to hypotheses about if humans and chimps (and/or HCLCA) have common design ancestry…, in the sense that windows 7 and windows 10 have common conceptual ancestry. And in that speculation, I’m open to consider it going either way… either that HCLCA was the template and mods were made to produce humans, or vice versa.
(While I don’t give it credence for numerous reasons, I would also be open to the idea that HCLCA or chimps were descended from homo sapiens… but there obviously lots of other reasons this is very dubious.)
I’d be open, likewise, to considering similar options between echolocating and baleen whales.
Point is, I have no strong reason to be skeptical about any of those hypotheses as regards common descent.
My skepticism strictly surrounds the ability of blind mutations to stumble upon that exponentially (1 in a googol?) rare combination that would be needed to get everything “just right” to produce such marvels of engineering or programming.
And my background, if interesting… I was a biochemistry major in undergrad until I fell in love with philosophy & theology. When I was younger I completely embraced all I had read or studied about evolution. I was exposed to some creationist thinking at some point, but was always skeptical of it (especially how neat and tidy, and how there was always an answer for everything. I remember laughing out loud at an AIG commercial I heard once that said the reference to “ice” in Job proved something about a recent ice age).
I was a Christian and took Scripture authoritatively, but was never convinced that I had to take genesis 1-2 as strictly literal… I was open to the hypothetical situation C. S. Lewis described about the origin of man.
In my biochemistry study, three things stood out… one, the incontrovertible evidence for microevolution. I did the experiments with fruit flies, on Petri dishes, etc., and watched the various generations demonstrate the slight differences and population genetic shifts.
Secondly, I began to be stunned by how intricate the design of life was, how “fine tuned”, how exact everything had to be, how delicate (salt content, ph, o2 transport, etc.), yet how robust (all the mechanisms to adjust and survive and repair). Not to mention the intracellular machinery. The design of the actin and myosin filaments put me over the edge, but especially was the fact that these designs were programmed into the genetics, the machinery and database of the DNA, ribosomes, etc.
Add all that together, and I couldn’t imagine any longer these feats of engineering happening from the same mechanism I was observing in the lab… I started thinking about it, and I began to doubt that, however long I could conceivably do experiments on those fruit flies, even if I lived for 50 billion years, I began to suspect those flies would just remain flies, and just letting them reproduce and selecting the most fit would never allow them to grow brains sufficient for intelligence as humans have. I did a study on what mutations could accomplish in fruit flies… and they’re all pretty ugly. “Deleterious” was an understatement.
Thirdly, I began to notice what I can only describe as all my professors having a blind faith in the theory. I asked some of my professors… one in particular, a devout believer in Darwinism, was nonetheless absolutely skeptical that mutations were a significant contributing cause of evolution. Something about them generally being deleterious if they weren’t neutral. He attributed evolution to natural selection interacting rather with genetic drift. We discussed it at length, and I recall recognizing that, if he were correct, then the first life would have had to contain within it all the DNA for humans and every other creature already “frontloaded.” Waiting for genetic drift and natural selection to eventually create humans. I raised this problem to him, and he simply acknowledged it, not seeing a problem. He was not a Christian but a devout Darwin disciple.
It was then I started especially noticing the cracks in the theory. And when I started to raise my various doubts to my professors, I began to notice the pattern of what seemed to me endless hand waves. “But if we give it enough time…” was the most common. “human intelligence isn’t that remarkable”, I recall. I started realizing that they had faith in a theory but even these learned men seemed to have blind faith in a process, believing it capable of near magic feats.
Somewhere in this process, I also began to recognize the philosophical problem. If a person is an atheist, they are bound to embrace a view of life that is naturalistic in nature. They have no choice. I began to realize that my professors could not, would not, would never, consider any alternative. This is long before ID was a thing (or before I’d heard of it, at least… 1991-1994 timeframe). They were philosophically committed to a naturalistic idea, they had to make blind mutations (or genetic drift) capable of these feats… they had no alternative. I was (as I still am) dubious of the creationist alternative (the only alternative that I knew of back then), But began to embrace my own personal version of ID, the kind that could conceivably be consistent with “theistic evolution” broadly defined. (I.e., consistent with common descent, but dependent on God’s intervention for major leaps). When ID came along later in Behe’s book and later that of Meyer, I found something resonated with me that I’d been myself contemplating for a long time.
(And then, after working with our nations sub force, and understanding how sonar systems need to work in aquatic environments, dolphin echolocation just put everything over the top.)
I could say more, but I fear I’ve already written a tome in answer to your inquiry. Hope it is at least remotely interesting.
If you did a biochem undergrad back in 91-94 you’re roughly contemporaneous with me (cell biology/genetics, 92-96), but you likely had less exposure to genetics than I.
I had a similar response to evolution then as you seem to have had then (and do now). Very similar, in fact.
Later, I would go on to do a PhD in biology and do some more genetics as part of that.
I guess the short response is that it seems to me that I am particularly well suited to understanding why you have the views you do, but also, in my opinion, why your training isn’t up to the task of dealing with (a) better evidence (biochemistry profs are usually lousy on the evidence for evolution and even worse on mechanisms) (b) more recent evidence (1994 is a long time ago), and (c) modern genomics and population genetics (which is really just a combination of (a) and (b)).
I guess what I’m saying is this - don’t be too confident in your training. It seems to be misleading you. I’m also basing that on your repeated misunderstandings of evolution as you have discussed them here - case in point, this: you continue to think evolution requires “one in a googol” - type events in order to work. Not so, my friend.
Anyway, thanks for the conversation. Did you notice that humans can learn to echolocate? Great video posted by @Chris_Falter. If humans can do that with their existing structures (!), how much more could natural selection shape a lineage over a few million years?
“natural selection” can accomplish only what random mutations give it, no? If the right mutations don’t show up, natural selection will produce nothing extraordinary.
I certainly don’t demand that kind of detail. However, when I consider the evolutionary pathways, I need to have some sense of numbers so that I’m not asked to accept it on blind faith.
So I consider the multitudinous possible mutations and evolutionary pathways that a HCLCA could undergo and find its descendants 500,000 generations later just as fit, or fitter. Could get stronger, quicker, more fertile, all sorts of possibilities and combinations. Could also remain essentially the same. Natural selection would be fine with that, and if no particularly beneficial mutations show up, we might be unsurprised. At least one pathway led from HCLCA to chimps, so there are certainly pathways that don’t lead to human level intelligence
So of the total possible evolutionary pathways that natural selection would permit if those mutations showed up (those that don’t cause a significant decrease in fitness) what percentage of those possible paths would lead to the kind of astounding, multifaceted intelligence and skill (art, engineering, science, philosophy, music performance, music appreciation, memory, mathematics, spoken language, reading, writing, literature, etc.) we humans have? The reprogramming of our brains to do these things is astounding.
But do we really have a ballpark number?
If I could be shown, say, that for every 1 path that led to our astounding human intelligence there were only, say, 4 paths that led to creatures of significantly lesser intelligence, then my skepticism would significantly abate. That would be completely plausible.
If, however, it were demonstrated that for every 1 path that led to our astounding human intelligence there were in fact a googol that led to alternatives, then you should be as skeptical as I am.
Do we have any way of even getting a ballpark guess at those numbers, though? If we in fact really don’t know if it is closer to 1/4 or 1/10100, then do we have any business having confidence one way or the other?
I’m afraid I will continue to maintain this, unless I can be shown otherwise. The possible combinations and recombination of mutations across populations of the size of our presumed ancestors across the 500,000 generations across 3 billion base pair is astoundingly high. We are talking possible combinations that are many, many exponential orders above a googol.
You’ve mentioned in the past that there’s not just a single combination that could lead to human intelligence, and I completely grant that… You could tell me, for instance, that there are 10999,999,999,999,900 possible combinations of mutations in the HCLCA genome that could lead to human level intelligence. That is uninteresting by itself… For if there are even 10999,999,999,999,999 total possible combinations of mutations, then we are still at a one in a googol chance of the right mutations appearing for natural selection to select in order to arrive at human intelligence.
I grant that we could be talking about odds far, far better than one in a googol… but given the sheer possible combinations, we could also be talking about odds many orders of exponential magnitude worse than 1 in a googol… All the more reason I think it vital that we have at least some ballpark estimation of the odds of these feats before we conclude one way or the other.
In another thread, I admired your astute identification of the fallacy of the converse: thinking that “a implies b” must lead to “b implies a”. Keep that awareness around for these observations too. Just because atheism does commit one to naturalistic explanations, doesn’t mean that naturalistic explanations commit one to atheism.
I think there’s a better approach than trying to ballpark estimate how likely mutations are to produce some trait like human intelligence (if only because we simply cannot do that calculation). That is to look at how malleable traits are to selective pressure, given the genetic variation that’s already been created by mutation or that occurs by mutation during an experiment. For a great range of traits, including things like intelligence, traits prove to be highly malleable. Selection can make organisms taller or shorter, faster or slower, lighter or darker. It can change the shape of limbs, mouths, genitals, heads, behavior patterns. Fully functioning states with altered traits must be easily achieved by mutations, since we see it happening all the time.
Another point would be to look at examples of convergent evolution - we see evolution, time and time again, finding similar solutions through different routes: the phenotypic parallelisms between placental and marsupial mammals would be a classic example; another would be the parallel increases in fitness in the early generations of the Lenski LTEE experiment. In both cases these observations would not be possible if mutations were limiting.
Edited to add: we even see convergence for echolocation at the protein level (prestin) as we have discussed here previously. This would not be possible if mutations were too improbable.
Closer to home, the Neanderthals and Denisovans also show us that there were multiple possible routes to a highly intelligent hominin like ourselves.
Sir, with deep respect, but I must point out you’re begging the question. The numerous arrivals at convergent evolution can only demonstrate the ease of arriving at these genetic destinations only if we first assume that these destinations were in fact achieved through the Darwinian evolutionary process, rather than by alternate means. But that is the very question I’m asking. Hence, we can’t assume that Darwinian evolution is the explanatory cause of convergent evolution, and then use that as evidence to argue for the truth of Darwinian evolution.
Daniel - for the LTEE, we have a complete, living fossil record of the entire process, sampled every 500 generations and frozen down. We thus can track every single mutation to within at most 500 generations of when it occurred. When we look at the mutations, they are all exactly the sort one would expect from regular processes.
Is that not good enough for you?
Even for the other examples, like the prestin one, we can see that the changes are convergent at the amino acid level, but not at the nucleotide level. Again, this is what we can predict in advance we should see for convergence.
When, in your mind, do they need to “show up” relative to the time at which selection operates on them?
The version of evolution you’re arguing against doesn’t exist. Did Darwin mention anything about the right mutations showing up? Did he mention mutations at all? Did the word “random” appear in any of his writings?
Indeed. The problem is that you’re not considering any evolutionary pathways that resemble reality.
Given your obsession with mutation, the first number you need to have some sense of is the ratio of existing variations to new mutations in a typical population of diploid organisms. You’re clearly assuming that the ratio is zero, are you not?
Diploidy is important. Neutral evolution is important. Do you understand why? If so, why does your straw man version of evolution assume that neither exists?
No, not like that, you clearly don’t understand it.
What’s that number, Daniel?
Good. Incremental progress! How long before?
Why is diploidy important, and why is it so obviously missing from your understanding of evolution, even your unrealistic description of it as only Darwinian evolution?
How much of the variation on which selection and drift act comes from new mutation? As you said, you need to have some sense of the numbers. You clearly don’t.
Sir, for the LTEE, it is demonstrating the kind of microevolution I have no issue or debate with, its examples of convergent evolution included. Hence my earlier thread about asking how long it would take, continuing to watch bacteria evolve at the microevolutionary scale but without seeing “macro” changes (e.g., a new, functional organelle I,parting a novel ability) before we could say the macroevolutionaryntheory had been disproven.
I completely agree, as I understand the experiment, that convergence has happened in various manners therein. (Do I recall correctly reading somewhere that the mutation to metabolize citrate happened more than once, independently?) And in these cases, I would completely agree that the pathway must not be particularly difficult if the evolutionary mechanism can stumble upon it not just once, but multiple times.
In other words, the LTEE demonstrates the kind of microevolutionary convergence I would take no issue with if it were suggested among sheep breeders, peppered moths, finches, or the like… that different pathways were discovered that led to say, heavy, shaggy wool, pigmentation, beak shape, or the like.
So in short, I have no issue whatsoever with the general microevolutionary principles, convergent evolution among them. I completely embrace, endorse, affirm everything about basic microevolutionary theory, Lenski’s LTEE among them. And convergence at the microevolutionary level I also fully endorse. But just as proof (and my belief) in microevolution does not convince me it is an adequate explanation for macroevolution, neither does the reality of convergent evolution in the micro scale convince me that it must have happened at the macro level.
I’ve given that more thought, and unless I am completely missing something, I realized it is perfectly expected even from the ID model why changes would be identical at the amino acid level but not at the nucleotide level… please indulge me, and see if I am completely missing something here.
Hypothetically, suppose with me that these prestin genes had been intentionally designed, and artificially imported or copied into both organisms.
If I understand rightly, over the generations, it would not be surprising for genetic mutations to occur and even accumulate in those specific bases where the mutations made no difference to the amino acid sequencing. natural selection only caring about any changes to the protein, not caring what genetic sequence created said protein.
For instance, if a sequence CUG were mutated into CUA, it would make absolutely no difference; the subsequent amino acid sequence, and hence subsequent protein, would be identical, and natural selection would not even take notice. That particular sequence could then experience a further point mutation and arrive at UUA, but again, make absolutely no difference to said organism.
So it seems unsurprising that, in different organisms, an identical protein could accumulate irrelevant mutations due to redundancy in the code, while still preserving the same amino acid sequence. Thus it seems to my amateur and novice understanding that this is exactly why one would expect, even from an ID perspective, to find correspondence at the amino acid, but not genetic, level. Am I completely missing something here?
