- Despite lack of observational basis, Darwin proposed Universal Common Descent (UCD) saying: “Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed“. He also said elsewhere (referring to UCD): “…the littlest creature (or four or five of them)…” With his remarks, Darwin left the door open to creation (“life was first breathed”), but since then, Neo-Darwinists have rejected creation and replaced it with belief in undirected abiogenesis while maintaining belief in UCD.
- UCD is incompatible with the current view of Earth as just an ordinary planet circling an ordinary star located nowhere special inside an ordinary galaxy. If Earth is “nothing special” and abiogenesis is an ordinary “arising” of life from non-living matter, spontaneous abiogenesis would be a trivial common occurrence here on Earth as well as throughout the Universe, and we would have many “trees of life” instead of one. However, until now, all abiogenesis experiments have failed to produce life, spontaneous generation has been rejected, and the Fermi paradox stands, all these keeping the single “tree of life” and UCD hypothesis still alive and still inexplicable.
- Conditions for starting life should be similar to those required for sustaining it. The Big Bang model mandates a beginning of life. Furthermore, once started life must be sustained by the same or very similar environment. And since life is being sustained now on Earth, abiogenesis should be ongoing contrary to all observations to date. Tidal pools, deep sea hydrothermal vents, and the undersurface of ice caps have been hypothesized to originate abiogenesis due to their persistent energy gradients, but no abiogenesis or its intermediate phases have been observed around these sites. Given these, the only methodological naturalistic alternative is ‘limited window of opportunity for abiogenesis which suggests primordial life substantially different than all known forms of life, and perhaps originating on another planet followed by panspermia. However, this alternative defies Occam’s razor and the absence of supporting evidence including the earliest ever known fossils (stromatolites) that are of commonly occurring cyanobacteria rather than of alien origin.
- Universal Common Descent requires an inexplicable biologic singularity. All known forms of life are based on the same fundamental biochemical organization, so either abiogenesis happened only once or it happened freely for a while but then it stopped when the ‘window of opportunity’ closed and only one organism survived to become the Last Universal Common Ancestor (LUCA) of all existing life on Earth. However, these two biologic singularities should be unacceptable given the lack of evidence and the assumption of continuity in nature. Furthermore, the second scenario requires two discontinuities: one for the cessation of abiogenesis and the second one for the bottleneck leading to LUCA.
- In conclusion, UCD hypothesis leads to a number of bad and very bad scenarios: a) Earth is “nothing special” should lead to a “forest of life” rather than a single “tree of life” and to ubiquitous abiogenesis (unobserved); b) Alien life plus panspermia is refuted by the Fermi paradox and oldest known stromatolites fossils; c) Single event abiogenesis is an unsupported and therefore unacceptable singularity; d) ‘Window of opportunity’ abiogenesis followed by LUCA bottleneck is even less acceptable double-singularity. And this brings us back to Darwin’s “open door” to creation, perhaps the most rational alternative that fits all biologic observations.
Con: Maybe abiogenesis is happening a lot. I think the already existing life would dispose of it quickly though.
Pro: if so, 1. We should be able to duplicate abiogenesis in the lab; 2. We should see at least some of the intermediate abiogenesis steps in nature; 3. Existing life can only process what looks like food. Cellulose is a well known organic material that cannot be broken down by a lot of organisms and is known to last as very long time in dry conditions.
The point is this: if you accept common descent of two populations that interbreed, on what grounds do you reject common descent of two populations with an equivalent degree of genetic identity that do not interbreed? I don’t recall you accepting that the same evidence – high degrees of genetic commonality between two groups – supports a common descent inference in the first case and in the second. Quite the contrary. But if you are telling me that you don’t in fact deny even simple speciation – cladogenesis – then I will happily concede my error.
This is precisely where ‘micro’ shades into ‘macro’: the region in which gene flow between two populations ceases. Do you think that gene flow between two populations can in fact cease, for biological reasons and not mere physical separation?
Except that they aren’t the same thing, so ‘exactly’ what? Microevolution is evolution within a gene pool, macroevolution starts with the separation of that gene pool into two. When biological isolation is complete, you have two (biological) species where once you had one.
But I accept common descent of populations exactly because they interbreed. E.g. dogs and wolves interbreed.
Based on what should I even suspect that when species do not interbreed, they arose by common descent? And how would one prove such common descent?
That isn’t “the essential claim” that evolution makes if one can even say there is such a thing. In either case, this point isn’t “missed” because it’s not what is being discussed. You may wish to discuss the evolution of novelty and we can do that, but it isn’t relevant to the subject of speciation (how does one species split and become two species?).
No he’s not demonstrated how things are eradicated, he’s just asking you to consider a thought experiment in which two incompatible breeds of dogs are the only ones left after the rest have disappeared and whether that wouldn’t technically constitute speciation? Whether that results in “novelty” (a term you haven’t even defined) is besides the point he is trying to discuss.
Nobody claims it would.
He’s giving an example of something that would constitute speciation under the biological species concept.
Yes, in Allan’s thought experiment there would be diversification of species.
The selective breeding for different traits of dogs show evolution can happen in respose to differential reproductive success, yes.
The differential reproductive success of finches with different phenotypes shows evolution by natural selection (as opposed to artificial selection in the example of dogs), yes.
No, nobody says that merely calling wolves and dogs different species shows that evolution happens. Nobody actually says “look, I can call them by different names, so evolution must happen”. Now you’re just being silly.
What? That makes no sense.
Paleontologists rarely consider two fossil species as being on direct lines of descent for pretty basic reasons of probability. Considering how many very similar-looking organisms that exist at any moment in time, and how rare fossilization is, it is extremely unlikely that you’re going to find fossils of species where one is a direct descendant of the other. It is simply much more likely that they are cousins. Even in the cases where you have a strongly-supported progressive chronology of morphological change in the fossil record paleontologists still estimate them as cousin relationships.
The chronologies of the layers of rocks in which fossils are found, and the magnitude of the genetic differences between extant species, is what implies the timescales of evolutionary change. It is not just made up because A looks different than B so it musta taken millions of years. That’s just not how it works. I know creationists like to claim this but that’s false.
Derive predictions from the hypothesis that they share common descent. For example, retroviral insertions are unlikely to happen in the same location and spread to fixation in two separate populations. Even more unlikely would it be that IF retroviral insertions happened in the same location in the genome in two separate species, that the insertion sequence would subsequently suffer the same mutations in the same locations independently and then those also rose to fixation in both populations.
One could go on and on with pseudogenes, retrotransposons, chromosomal rearrangements/fusions/fissions etc. etc.
Yes, I gleaned that much. But why is interbreeding a sign of common descent? You seem to think, naively, that interbreeding is somehow independent of genetic sequence alignment. But in fact, as far as the vital ‘checkpoint’ of F1 meiosis is concerned, interbreeding depends on genetic sequence alignment. If genomes differ by too great a degree, reciprocal crossovers cannot form correctly, and meiosis fails. This is why many hybrids are sterile.
Based, inter alia, on the extent of genetic identity – that same thing that interbreeding success ultimately depends on. There is no sharp discontinuity between populations that can interbreed and those that cannot in terms of the percentage of their genetic identity. There are examples of every stage of speciation, right through to extremely rare instances of hybrid fertility, but you won’t go that extra step and accept completion of the process through to interbreeding cessation – despite the continuity of genetic commonality beyond this point.
There is no sound explanation for the substantial amount of genetic commonality above the species level, other than common descent. It’s certainly the explanation you seem to accept within, so I don’t know why it cannot be exported across the boundary of fully separated gene pools. This is a mechanistic explanation – sequences are identical, or nearly so, because they had their origin in the same DNA molecule.
You are kind of confirming the position you rejected – I said that you deny even simple speciation, you said I remember wrong, yet here you are for all the world appearing to set your stall out to deny even simple speciation, QED.
The problem here is that, insofar as you say that there is no sharp discontinuity between species, you are rendering the term species meaningless. If there are no distinctions between species, then what is speciation? All you have is a continuity of divergence. You have no solid species because it is all nicely filled with unbroken transitional stages. And we see those transitional forms right now all over the place, right?
Somehow I am still stuck seeing species in nature. Some distinctions between them are sharper, some less sharp, but “missing links” are the expected norm. Also species that stay the same for millennia, reluctant to evolve in any direction, are the norm.
Different species also have different nature, as evident for example in intra-species variation. Some species vary immensely and easily over a few generations, such as dog breeds. Others vary barely at all under the same circumstances. Looks like their genetic commonality or identity as you say it does not mean as much as you think it does.
Categories do not have to be dichotomous to have utility. Most of the time, species can be identified as discrete, non-interbreeding collections. But clearly, if one has a progressive mechanism separating one gene pool into two, one would find many unsatisfactory halfway-house situations among the clear-cut ones. As we do.
Speciation is the divergence of a single gene pool to become, utlimately, two. The separation is sealed by the origination of a biological barrier to reproduction, which completes the process even on removal of the geographic, temporal or ecological one which starts the ball rolling.
Yup – at least temporally, although at any given moment in time one can see discrete collections laterally. Still, there is a quasi-discrete marker for a particular point in that continuity: the point of cessation of even hypothetical interbreeding between two diverging populations. That is the point at which genes must stop flowing between the populations – sex is their only route. Prior to that point, there is a case for saying that it’s ‘only’ microevolution, even if introgression occurs but rarely. But when you have microevolution in two separated gene pools, then you have macroevolution. They are diverging in a completely uncorrelated manner; nothing flows to keep them in step, whereas a single gene pool is stirred somewhat, mixing in alleles from all directions.
You have some ‘solid’ species, and some less clear cut. That’s nature for ya.
It requires an explanation, which I can provide and you cannot.
Nicely explained Allan.
The second one is obviously the one that is designed.
Are there any here who disagree that there is organisation at the level of the genome, or the level of the cell, or the organs? Surely everyone agrees that individual organisms and their development are organised. The fact that we use the word ‘organism’ gives it away. But who here believes that life as a whole is organised? We can see clearly organisation at each ascending level, so why should it stop at a particular level and not continue on up to the highest level, the biosphere of the earth? There is organisation at every level.
The levels of living systems from DNA to the complete biosphere show their, self-repeating, fractal nature.
Brian Goodwin was interested in nature’s form producing capabilities.
Like many of us, he did not believe that neo-Darwinian processes are capable of building the novel forms seen in nature. Genes do not create anything.
In this video Goodwin discussed the fractal nature of various systems in life.
It is not a very good recording but here is a fairly accurate excerpt of what he says towards the end:
This order gives us examples of how the whole is reflected in the parts.
What kind of young earth whacko fundamentalist is this guy…wait, what, he is a Professor of Biology, what the heck??
How can that be? Doesn’t he know about the consensus? Doesn’t he know this is settled science, the most robust and evidenced theory in the history of man kind? I mean yea, they call it a “theory” but in science that means its proven fact. That’s just how science talks. There is no debate in the scientific community.
What a nutjob.
Whether he’s right, or even makes sense, is unimportant of course. The mere fact that he disagrees with something evolution-related is enough for phoodoo(and CharlieM). So much so that phoodoo completely skipped over where he wrote “The small-scale variation and the detailed adaptation of organisms to their habitats are very well explained by neo- Darwinism”. Yet phoodoo has labored intensely on this website denying the existence and/or efficacy of natural selection.
This is rather OT of course, but it makes little sense to me to regard diffuse populations as in any way equivalent to an individual soma. The soma is coordinated for a purpose (marvel as word gamers buzz around that word choice like flies round shit!): the production of multiple genome copies. Cells forego their own direct replication for the replication of copies of their genes in the germ line. Left to their own devices, cells beat shit out of each other, because their fates are uncoupled from any common purpose (bzzzzz!). In a soma, they are compelled to act in harmony by the gametic exit. Individual organisms, not so much.
1. You can’t seriously claim “it might be this or that” without any hard evidence. The scientific method requires hard evidence, not imagination.
2. In 3 mil yrs. of separation, bonobos and chimps did not diverge. They were not even considered “different species” for a while. “Divergence due to reproductive isolation” scenario fails.
3. Point is, “reproductive isolation” has not been shown to cause transmutation of species.
What a feeble response. Because we don’t know the specific isolation mechanism in a particular case, it was none of them, and some bloke in the sky did it? When Creationists get on their high horse about the scientific method, I piss myself laughing.
So if in case X reproductive isolation did not arise, it did not arise in any? Haha again, more incontinence pads required. Let us for a moment imagine what you’d be saying if bonobos and chimps could not interbreed. “There is no evidence divergence led to their reproductive isolation”. Then something haughty about the scientific method.
Tell me, why are bonobos and chimps different? Were they created like that, or did they get like that?
We are not talking about ‘transmutation’, we are talking about cladogenesis. If microevolution can occur, independently in 2 lines, you are arguing that no amount of it can lead to infertility. Even if every chromosome ultimately had no homologous sequence in any other, somehow they would find a way to generate a zygote and a successful meiosis, against all biological evidence.
Compelled huh? Like they have a mind of their own but have been brainwashed?
You just don’t understand scientific creationism.
I think this is where the creationist would say that by some mysterious force mutations run into a “barrier” that prevents the chromosomes from mutating any further. With zero evidence of course.
You’ll notice that I made parenthetical reference to the expected reaction to ‘purposive’ language in that very comment. Bzzzzzz!
True, although I think it’s as much that they simply don’t grasp the biology. They don’t understand the relationship between diverģence and the compatibility of haploid genomes presented to F1 meiosis in hybrids. I’m not sure they even grasp divergence itself, despite the claim that they ‘accept microevolution’. They accept it, but none of its corollaries!
Does anyone? Is there such a thing? Genuinely?
Bathe in a solution of 99% denial, seems to be the basic recipe. God kind of precipitates out. It’s a bugger when your theory isn’t understood by anyone else though, eh?
Asking for hard evidence is “a feeble response”? Because belief in evolution is all you need?
Meanwhile bonobos and chimps show no “divergence of character” over 3 mil yrs. Whatever your alternative imaginary scenarios might be.
Cladogenesis nonsense. Microevolution nonsense. Where’s the “transmutation” promised? Infertility is not the promised land.
You keep asking and it’s right in front of your eyes.
One thing we know for sure: Darwinist evolution falls flat on its face on every claim.
No, dismissing even the possibility of reproductive isolation because we don’t know the specific mechanism in a given case is a feeble response. Made all the more feeble by being your support for a positive case; that if we don’t know which particular isolating mechanism it was, some magician waved its wand.
You keep scare quoting a phrase I haven’t used. If bonobos and chimps show no divergence, why are they different?
A stunning refutation, Professor. Yah boo sucks and all that.
“Of course Creationists accept microevolution'”, insists a correspondent. But when pressed, it appears that nothing changes even slightly.
No, but it is the reason why two populations cannot interbreed, and hence are separate species, on the BSC. The question is not ‘is speciation the magic I seek?’, but ‘can speciation happen?’. And you are clearly saying ‘no it can’t’. NO amount of uncorrelated change even happens between two isolated groups because, well, bonobos and chimps. And if it did happen it could not reduce their interfertility, because, well, bonobos and chimps.
Therefore, if we find two groups that cannot interbreed, they cannot have got like that, because look, here are two groups that didn’t. Did I mention bonobos and chimps?
It’s funny, you are pursuing elsewhere an argument on inference complete with p values and science and stuff. Here, we have an inference – common descent, inferred from the high degree of genetic commonality both between group pairs that can interbreed, and those that cannot. Your approach in this instance is simplistic denial. Mr Consistency.
Or do not, or will not, or have not , or didn’t yet this week…?
Some groups can interbreed, and some cannot. This is a simple matter of fact, so I’m not sure what you hope to gain by this foolish mockery of my noncontroversial statement. When a mummy frog and a daddy frog love each other very much …
I’ve lost count of how many times I’ve been told that creationists accept speciation and microevolution.
But to borrow a phrase from Mung: Except when they don’t. Which is the vast majority of the time.
They will pay lip service to the concept of microevolution, yet when it comes to specific cases they deny them. Like antibiotic resistance in parasites and bacteria. Suddenly that’s not evolution at all, it’s “adaptation” which-totally-isn’t-evolution. Or the change in the frequency of the alleles in the peppered moth populations. Denial denial denial. Did you accept microevolution? No.
They’ll claim they accept speciation “within kinds”, we ask for what kinds are, and they say mostly nothing, or “cat-kind”. So we compare house cats to lions and tigers, and they’ll suddenly have a big problem with speciation. You didn’t see them evolve to the state of infertility, so there’s no evidence it happened. Hmm. Should they turn out to accept speciation of “cat kinds”, we point out the same degrees of difference (genetic and physiological) separate humans from other primates, and they’re right back to denying speciation in all it’s shape or forms again.
And round and round it goes.
I’m not quite clear on the details of how a mummy frog would have sex and not sure I want to know.
I don’t take him to be saying microevolution doesn’t happen, but with Nonlin one can never be sure.
Indeed, though it’s hard to read ‘microevolution nonsense’ as acceptance. No doubt Nonlin will be along in a few days to clarify…
Ah, the American audience, I keep forgetting. Mommy, it would say in the subtitles.
Interbreeding and genetic isolation are not the answers to anything. Try to understand that “reproductive isolation” is NOT the hard evidence for “evolution”. In fact it’s trivial.
“Species and speciation” are mumbo-jumbo like most anything in “evolution”. I know it’s hard, but try to define these in a logical, non-circular manner. You can’t!
“Divergence of character” is essential for “evolution” to have a chance, but is just not happening. We have seen it over and over again in epigenetic inheritance, the peppered moth color, the Darwin’s finches’ beaks, and antibiotic resistance that goes away when antibiotic use decreases. All these were supposed to demonstrate “evolution” but in reality demonstrate it’s failure to materialize because none of those diverge experimentally into something else.
It seems you just can’t grasp why “bonobos and chimps” are such strong evidence against evolution.
Different people have different theories. And then we dispute them to find the best. That’s how science works. No disagreement in “evolution” tells you it’s pseudoscience.
1. Some (including the ID crowd) accept microevolution defined as observable adaptations in populations, while rejecting macroevolution defined as the never observed and very much doubtful Darwinist “common descent”. The problem is that micro and macro are just generic qualifiers that come in pairs, while evolution – the word retained – is in fact the concept in question.
2. Accepting microevolution creates confusion and is self defeating for those that reject Darwinist macroevolution. A better choice than microevolution is adaptation – an ancient concept (predates evolution), and an observed feature of all living organisms.
It is the answer to the question of how species which cannot presently interbreed can have common ancestors. That, after all, is the topic of the thread: Common Descent. If it’s trivial, why do you dismiss it?
Speciation is the process by which biological reproductive isolation evolves. Species (on the BSC) are populations that cannot interbreed. You find that circular?
Divergence (of haploid genomes presented to meiosis in hybrids) is an inevitable consequence of microevolution in two separated lineages. Since we have examples across the spectrum of varying degrees of infertility, I’d say it is happening.
I snipped the rest, because it is irrelevant to the question. Speciation is about cladogenesis, not phylogenesis. You need to grasp that.
They are divergent – else how did they come to be different? I’ve asked this several times now. And exporting the parameters affecting one population pair to the entirety of nature is something of a logic fail on your part. One species failing to become two in a particular time frame is not evidence it can never happen. Especially given the strong evidence that it does.
I think it’s not so much that accepting microevolution ‘creates confusion’, but that you recognise that if you did so you would start whizzing round the plughole in a vortex from which you cannot escape, so you cling doggedly to a rather ludicrous redefinition strategy. Get rid of the nasty ‘evolution’ word and we can all breathe easy.
Whatever. If a process – call it what you will – results in an uncorrelated change of x% in time t in each of two populations of genomes, such that their percentage relatedness cumulatively diminishes by roughly 2x% in each t, can this process never result in mutual infertility? That would be peculiar – as relatedness gets down to 1% or so, they can still do meiosis … !
Well, if so, and we are presented with genomes that are (say) 98% identical but cannot interbreed, to what can we attribute that high degree of alignment, if not common descent?
Microevolution is changes in allele frequencies in a population. It has nothing to do with adaptation.
1. You obviously don’t understand the topic of this thread.
2. “Mumbo-jumbo” is not same as “circular”.
3. Infertility does not lead to the promised ‘transmutation of species’
4. “Divergent” is not same as “different”.
If bonobos and chimps are so close after 3 mil yrs (no more different from each other than say Inuit and Pygmy) , then humans and chimps cannot be as far as we are in 6 mil yrs in ESSENTIALLY the same environment. That’s the mega problem staring you in your face.
Cumulative is the necessary yet unfulfilled claim. And that precisely is your problem.
Peppered moths that revert back to a previous state rather that continue to diverge,
Darwin’s finches that do the same,
Antibiotic resistance that disappears instead of spreading once the antibiotic stimulus is removed
LTEE that failed to produce anything other than the eColi it started with
Lots and lots of “living fossils” and no proven “transitional organisms”
Epigenetic traits that disappear after a few generations intead of leading to “divergence of character”
All kind of “beneficial” population traits including in humans that refuse to spread beyond a small subgroup
Because you chose to define “changes in allele frequencies” as “microevolution”?
Don’t you know the immune response involves “changes in allele frequencies” in a population under attack? It’s happening every year when the flu season comes. Are you then “microevolving” into something else?
How it works:
“Though the general structure of all antibodies is very similar, a small region at the tip of the protein is extremely variable, allowing millions of antibodies with slightly different tip structures, or antigen-binding sites, to exist.”
No, that was not my choice. How do you choose to define microevolution?
Why does microevolution not have anything to do with adaptation? It seems to me that adaptation can happen through changes in allele frequencies in a population. An example would be the peppered moths.
Fuck off. If you pen an OP on Common Descent and then deny the relevance of two groups being commonly descended, you come across a bit foolish, and not fully in command of the material.
I dare say. But you’ve used both. The first was just foolish petulance, but your challenge was to define speciation in a non circular manner, which I did. Your response: to blink uncomprehendingly.
Nor does it need to. Speciation is cladogenesis, not phylogenesis. It is the reason two non interbreeding species can be commonly descended. For, like, the tenth time. Are you just going to keep repeating your mantra too? That’ll be fun.
I dare say. But why are they different?
There is absolutely no reason to suppose the history of one species pair should preclude a different history in another. The environment doesn’t have much to do with it. Evolution is, after all, random, as Creationists hereabouts gleefully remind us. That’s important in this context.
Still, why is everyone so obsessed with chimps? I mean, they’re cute and all, but … 🤔
So what stops either lineage from changing? If change can occur at all, and repeatedly, it can only be cumulative. There is no evidence that genetic change has ceased in any lineage.
Of course, I can investigate this. I can do sequence alignments on species pairs and find every number represented for percentage alignment. That sure looks looks like cumulative to me. Of course you’d argue that as ‘circular’. That’s the word they tell you to stick into debate at Creationist Seminary. But it is a pattern that requires explanation. And I could cast it in terms of hypothesis testing, as you attempt to do in your intelligent design detection thread. Valid when you do it, I guess.
It was someone’s choice. I explained “microevolution” is a misnomer. Did you even read?
We always learn from examples. In this case, the example contradicts the narrative, of course.
“The environment doesn’t have much to do with it”?!? Do you even know your own dogma?!? Are you a bot?!?
No, “evolution is NOT “random”. Instead, there is NO “evolution”.
I will not address the rest of your nonsense for the n-th time.
One example is hardly definitive. It is a ridiculous argument. On the one hand you say reproductive isolation is ‘trivial’, on the other – based on a solitary example – you say it does not happen. Which is it?
Perhaps you don’t understand evolutionary theory as well as you think. It does not predict that two isolated populations in the same environment will undergo exactly the same mutations, even if subject to broadly the same selective pressures.
Here’s a case in point: bonobos and chimps have different chromosome numbers. Why?
Sure, if you say so. So why are bonobos and chimps different? Take chromosome number for example.
Honestly, I don’t see why. It seems an entirely reasonable syllogism to me. You can either argue that change never occurs, or that there are limits to change. If change never occurs, I agree it cannot be cumulative. But if change occurs, and there is no ‘book-keeping’ of genes beyond any current population, I don’t see what stops it being cumulative. Hence my stupid question.