Uncommon Descent Serving The Intelligent Design Community

We can’t understand evolution without understanding stasis and extinction

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Recently, a reader wrote to me concerning Stasis: Life goes on but evolution does not happen. Reader asked,

Concerning horseshoe crabs and coelecanths, could it be possible that marine-environment organisms are under less pressure to change/evolve than terrestrial organisms?

I replied,

Thank you very much for your thoughts!

You could of course be correct. And then we face several conceptual tasks prior to research:

1. Specifying testable hypotheses as to why the longest-conserved marine life forms were under less pressure to change/evolve. We must not fall into the trap of assuming that they must be under less pressure because they didn’t evolve.

We don’t know for sure that pressure has much to do with it. That is, we assume so. But there is no known law of physics or chemistry that requires change/evolution, as opposed to stasis/extinction. There may be other factors in why life forms do or don’t change/evolve. How can we weight the ones we find?

Conversely, why are terrestrial life forms under MORE pressure to change/evolve?

2. Many marine life forms survived tens of millions of years, then went extinct. One thinks of the Cambrian biota. We need a hypothesis that can account for why life forms that have shown long-term stasis later disappear, one that correlates to our hypothesis as to why some just persist.

3. Some life forms strut the stage a short while and then disappear – one problem is that in our present state of research, we are much less likely to find enough of them to establish that that is so, but research does continue after all, and recent finds have been promising.

4. Some extinctions are so complete – all dinosaurs, for example – that they constitute either a special case (that currently relies almost entirely on storytelling, as opposed to biological principles), or they could shed much light on both extinction and stasis.

It is early days yet. But this seems clear to me: We will not understand evolution if we do not understand stasis and extinction. If there are any general principles that would turn the history of life from history into science, they must incorporate all three outcomes. – Denyse O’;Leary, for Uncommon Descent News

Anyone wish to weigh in?

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Comments
Interesting to observe Moran is unable to discriminate between phenome evolution and genome evolution. Together the data demonstrate Limulus cannot phenomically evolve, while it can genomically. If the ancient coelecanth would have phenomically evolved, we would not describe them today as coelecanths. It is the phenome that evolves because it can do so. It can only do so when frontloaded cryptic info is released. If genomes are not frontloaded to evolve, the phenome will not change much. Stasis of the original bauplan results. We should start to find out where the bauplan hides. And then I do not mean HOX genes, which are merely executors of the bauplan.Peer
November 4, 2015
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Mung, "We can’t understand evolution without first misunderstanding evolution." Sounds good. Not quite though, I think. More accurately, we can't understand evolution without misunderstanding nature. Hmmm.bFast
November 3, 2015
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Ahh, someone finally brings up the "optimally evolved" argument.
Therefore, if a species population is well adapted to its environment, there wil be little or no impetus toward changes to allele frequencies within that population.
There are several problems with this and one is right there in your post:
Evolution is not a linear process towards a goal
You said it. There's no goal so it doesn't even know the difference between unevolved and evolved. It just does. Evolution (blindly selective randomness) deals with the NOW, not the future, not the past, the NOW. You cannot claim that a creature is well adapted over millions of years and at the same time claim that its predators and preys are supposedly still evolving or that its environment is changing. And you cannot claim its environment remained the same over even a million years, that's just absurd. The purposeless/goaless nature of evolution is the reason convergent evolution and evolutionary stasis are oxymoronic absurdities only believed by the indoctrinated.
Thst’s the reason cockroaches appear like they have not changed since millions of years ago
That's the evolutionary assumption based on circular reasoning: it didn't evolve (much) -> why? -> because it was well adapted to its environment -> how? -> because its environment didn't change (much) -> and you know this how? -> because it didn't evolve (much) -> ... OTOH, what is observable is that there was never any evolution in the first place. All the equivocations from the Darwinists doesn't change this fact.Vy
November 3, 2015
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I just want to add to the debate like this: Evolution is not a linear process towards a goal, nor a process of changes in morphology unless there are good (from the evolutionary POW) reasons why changes might confer advantages to a population. Therefore, if a species population is well adapted to its environment, there wil be little or no impetus toward changes to allele frequencies within that population. Thst's the reason cockroaches appear like they have not changed since millions of years ago. Nevertheless, their DNA still has been accumulating mutations at a certain rate. The distinction is that conditions has not made made mutations affecting morphology advantageous. That's what we always should keep in mind when looking at the landsacpe of evolution. DNA keeps changing all the time but unless a shift between allele frequencies within a poulation occurs, morphology will be rather static. That's the best I can do to explain how the subject is seen from my layman's POW. Unless I am mistaken, cells are mutating all the time. My body cells are different from the body cells I had at birth. I've been lucky, no cancer cells yet, at 85.Cabal
November 3, 2015
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We can't understand evolution without first misunderstanding evolution.Mung
November 3, 2015
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bFast: we are pond scum “We are made of starstuff.” — Carl SaganZachriel
November 3, 2015
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Barbara Stahl wrote about coelacanth anatomy: The modern coelocanth shows no evidence of having ... internal organs preadapted for use in a terrestrial environment. The outpocketing of the gut that serves as a lung in land animals is present but vestigial in Latimeria. The vein that drains its wall returns blood not to the left side of the heart as it does in all tetrapods but to the sinos venosus at the back of the heart as it does directly or indirectly in all osteicthyans except lungfishes. The heart is characteristically fish-like in showing no sign of division into left and right sides, and the gut, with its spiral-valved intestine, is of a type common to all fishes except the most advanced ray-fins. At one time, paleontologists thought that coelocanths, like air-breathing tetrapods, had nasal passages that opened into the mouth cavity, but dissection of Latimeria disroved that idea. Despite their fleshy fins, the coelocanths were no nearer the ancestral stock of land vertebrates than the dipnoans, fishes in which internal nares, or choanae, were also shown to be nonexistent. (Barbara J. Stahl, Vertebrate History: Problems in Evolution, p. 146 (Dover Publications, 1985).)geodude
November 3, 2015
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If there's discernible phenotypic change, it was obviously due to random genetic drift, therefore evolution. No discernible phenotypic change, also random genetic drift, you just can't see it. Therefore evolution. You have to look at the genomes, before and after. Modern science.Mung
November 2, 2015
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Living Fossils: Wollemi Pine 150 million years old Professor Carrick Chambers, Director of the Royal Botanic Gardens in Sydney, has said of the sensational discovery of a type of tree in Australia’s Blue Mountains (200 kilometres west of Sydney, in Wollemi National Park) that it was like finding a ‘live dinosaur’. This is because the tree, nicknamed the Wollemi pine, is known from fossils classed as so-called Jurassic age around 150 million years ago, but not from fossils in rocks of later periods.geodude
November 2, 2015
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Living Fossils: graptolite 300 millions old In 1992 Noel Dilly, sorting through a pile of unlovely organisms retrieved by French oceanographers from the seafloor off New Caledonia, found himself looking at a graptolite: a strange sea creature last seen alive around 300 million years ago.geodude
November 2, 2015
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Many of the primary structures of animal life were already in place long before the coelacanth ...
Not that blindly selective randomness can explain the origin of any of those structures but what's the relevance of this obvious fact?Vy
November 2, 2015
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Y'know Zach, I was putting away a bunch of groceries, and laughing at your stupid response. It made no sense to me at all. Then the light came on. Y'know, there's huge truth in what you say. The difference between the first deuterostome and the single celled organisms that were its recent ancestors is astounding. In a way the difference between the deuterostome and its ancestor 5 million years preceding it is far greater than the difference between the coelacanth and the Moran. Thanks for the insite. I took the thought one step further, and thought of the first DNA based pond scum. It surely existed by 3.5 billion years ago. Yet the vast difference between it, and the "pond" that preceeded it is just amazing! In a real way, we are pond scum. In simple truth there is far more similarity between the Moran and the pond scum than there is between the pond scum and the rock. And the coelacanth goes on and on without taking on any noteworthy morphological changes. And the Zachriel and the Moran go on and on without taking on any new wisdom.bFast
November 2, 2015
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@bFast, lol. I'm pretty certain what Larry claims is "evolution" is actually adaptation. How he can keep on claiming that coelacanths developing obvious adaptations to their environment to turn into ... wait for it ... coelacanths in >300,000,000 years is evolution while at the same time claiming that for example, some dog creature changed into a whale creature in <10,000,000 years is beyond me. That fish had more than THIRTY TIMES that period of time to turn into Coelanceratopsglodonasaurus rexipiticus and yet it didn't it. It still remained a coelacanth. If your best explanation is "oh look, the ancient coelacanth was fatter, had bumps, x, y, z etc. while the modern one doesn't", then to say you need help would be a gross understatement. Larry, in case those random reactions in your 3 pound meat made you miss that, I repeat, GROSS UNDERSTATEMENT.Vy
November 2, 2015
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Many of the primary structures of animal life are due to a Common Design, just as Linnaeus envisioned.Virgil Cain
November 2, 2015
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bFast: Zachriel for clarifying your objectivity and critical thinking skills. It was a joke with a point. Many of the primary structures of animal life were already in place long before the coelacanth first evolved.Zachriel
November 2, 2015
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Thanks, Zachriel for clarifying your objectivity and critical thinking skills.bFast
November 2, 2015
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bFast: If I rate the morphological changes between you and your 400,000,000 year ago ancestor at 100, how would you rate the morphological difference between the modern coelacanth and the 400,000,000 years ago. Seen one deuterostome, seen them all.Zachriel
November 2, 2015
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Dr. Moran, sometimes it seems that you babble. From where I sit, I see "it [the coelacanth] was believed to ... have evolved into roughly its current form approximately 400 million years ago." Wikipedia (coelacanths) If I rate the morphological changes between you and your 400,000,000 year ago ancestor at 100, how would you rate the morphological difference between the modern coelacanth and the 400,000,000 years ago. Again, known morphological difference between human and ancestor = 100, known morphological difference between modern coelacanth and ancestor = X. What, in your expert opinion, is X?bFast
November 2, 2015
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Vy, "Larry M$#@*%g continues ..." Vy, watch your toungue. No need to resort to personal insults. Larry Moran, "I should have known that IDiots are clueless..." Sorry Vy, I take that back.bFast
November 2, 2015
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Larry Moran:
The claim was that coelacanths haven’t evolved. Perhaps I erred in assuming that people on this blog would know the scientific definition of evolution. I apologize for making that assumption. I should have known that IDiots are clueless about evolution.
We're worse than clueless.Mung
November 2, 2015
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A coelacanth evolving into a modern coelacanth is exactly what baraminology predicts. But then again Larry is clueless as to what his opponents say.Virgil Cain
November 2, 2015
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Larry Meatbag continues to miss the point.Vy
November 2, 2015
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PaV says, So, instead, you compare certain markers of neutral drift found in the genome to other such markers in other extant species which have changed; and you say that the coelocanths have changed just as much as the others. IOW, genetic drift is the same. But, of course, it’s rather obvious that in the case of the coelocanth all this “drift” has done nothing–or almost nothing; hence, it is trivial. The claim was that coelacanths haven't evolved. Perhaps I erred in assuming that people on this blog would know the scientific definition of evolution. I apologize for making that assumption. I should have known that IDiots are clueless about evolution. BTW, are you convinced that the internal organs of modern coelacanths are exactly the same as their ancestors? Are you certain that none of the enzymes of the modern species are better adapted than the enzymes of their ancestors? You must be certain of both of these things if you assume that all of the deduced evolutionary changes are trivial. What is your evidence? You must also have rejected all of the changes in external physical appearance that were documented in the links I posted. I wonder why you did that?Larry Moran
November 2, 2015
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And let us not forget the voles: Rodent's bizarre traits deepen mystery of genetics, evolution:
The study focuses on 60 species within the vole genus Microtus, which has evolved in the last 500,000 to 2 million years. This means voles are evolving 60-100 times faster than the average vertebrate in terms of creating different species. Within the genus (the level of taxonomic classification above species), the number of chromosomes in voles ranges from 17-64. DeWoody said that this is an unusual finding, since species within a single genus often have the same chromosome number. Among the vole's other bizarre genetic traits: •In one species, the X chromosome, one of the two sex-determining chromosomes (the other being the Y), contains about 20 percent of the entire genome. Sex chromosomes normally contain much less genetic information. •In another species, females possess large portions of the Y (male) chromosome. •In yet another species, males and females have different chromosome numbers, which is uncommon in animals. A final "counterintuitive oddity" is that despite genetic variation, all voles look alike, said DeWoody's former graduate student and study co-author Deb Triant. "All voles look very similar, and many species are completely indistinguishable," DeWoody said. In one particular instance, DeWoody was unable to differentiate between two species even after close examination and analysis of their cranial structure; only genetic tests could reveal the difference. Nevertheless, voles are perfectly adept at recognizing those of their own species.
Yup after all this “evolution” a vole is still a vole. This study alone should cast a huge shadow over Common Descent and macroevolution.Virgil Cain
November 2, 2015
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Larry Moran:
Furthermore, by looking at the evolution of their genes and proteins we can see that the rate of changes taking place at the molecular level are not much different than the changes taking place in all other lineages. In other words, they have evolved from ancient ancestors just like every other modern species.
Isn't this a tautology to the extent that it might be significant, and trivial when not tautological? You cannot compare the genetics of extant species with those that are extinct. You simply analyze their genomes. Were your statement signifcant--in the sense that actual, significant change took place--this would require comparison to extinct coelocanths, e.g., and that's not possible. So, instead, you compare certain markers of neutral drift found in the genome to other such markers in other extant species which have changed; and you say that the coelocanths have changed just as much as the others. IOW, genetic drift is the same. But, of course, it's rather obvious that in the case of the coelocanth all this "drift" has done nothing--or almost nothing; hence, it is trivial.PaV
November 2, 2015
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There is a bigger stasis thing going on. Most of our body parts have not changed since we were fish or some furry thing. Our eyes and liverm and immune system are the same as most of biology. Unless massive convergent evolution has been going on THEN we are walking living fossils ourselves. Good name for a book! These examples do show so little change or less change then differences between people groups today. Yet so long did not change them and that time change everything else fantastic. This is very unlikely. Whats so special about their home life?? Naw! Its just because the seas didn't bring as much extinction as on the land since the flood. In fact possible all sea creatures might still be there somewhere. Keep looking. Surely lack of change hints there is never been change based on evolutioonary mechanisms. AGAIN the fossil record shows great stability with final extinction. Horses look just as they did 20 million years ago. Not my timeline but theirs.Robert Byers
November 1, 2015
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Unfortunately, your question implies that horseshoe crabs and coelacanths have not evolved for millions of years and that just not correct. There are several internet sources you could consult but the bottom line is that the modern species of horseshoe crabs and coelacanths are significantly different from the ancient fossilized versions.
Really? That's your best shot? In all your "distinguished" glory, that's the best excuse you could come up with? Pathetic. We're expected to believe . . . Doggy-creature -> whale in less than 10 million Darwin years. And yet . . . Ancient octopus -> Modern octopus in 95 million Darwin years. Ancient jellyfish -> Modern jellyfish in over 150 million Darwin years. Ancient horseshoe crabs -> Modern horseshoe crabs in over 200 million Darwin years. Ancient Coelacanth -> Recent Coelacanth in over 340 million Darwin years. Ancient jellyfish -> Modern jellyfish in over 500 million Darwin years. Ancient bacteria -> Modern bacteria in over 2 BILLION Darwin years. And that's not even the oldest Darwinian moyboy living fossil age of bacteria! Man, if you can't see how empty little excuse is then you need serious help.Vy
November 1, 2015
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You two guys are out to lunch. The horseshoe crabs and coelacanths have had to undergo the same environmental pressures as all the other creatures in the ocean over the same period. They had to adapt to the same extreme climate changes just like everything else. And yet, compared to other lineages, they have not changed much. Whatever change is observed between the fossils and today's specimens, can be attributed to neutral drift or simple adaptation, which do not involve RM+NS. Heck, one can breed dogs within a few generations that are markedly different from their ancestors. Did that involve Darwinian evolution? No, it did not. Are they a different canine species? No, they are not. Horseshoe crabs and coelacanths are still horseshoe crabs and coelacanths. Not some other species, or what have you, that might have popped up by some serendipitous Darwinian magic.Mapou
November 1, 2015
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Larry, Yeah, but the creationists wouldn't have much to talk about if they didn't continually assume that popular/media misunderstandings of scientific topics represented mainstream science on these issues.NickMatzke_UD
November 1, 2015
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Here's how I would reply ... ----------------------------------- Thank-you for asking an interesting question. Unfortunately, your question implies that horseshoe crabs and coelacanths have not evolved for millions of years and that just not correct. There are several internet sources you could consult but the bottom line is that the modern species of horseshoe crabs and coelacanths are significantly different from the ancient fossilized versions. The change in physical appearances of these organisms may be less remarkable than the changes in other species over the same length of time but that doesn't justify the claim that they haven't evolved. Furthermore, by looking at the evolution of their genes and proteins we can see that the rate of changes taking place at the molecular level are not much different than the changes taking place in all other lineages. In other words, they have evolved from ancient ancestors just like every other modern species. Coelacanths are not living fossils Coelacanths are not living fossils. Like the rest of us, they evolve Coelacanths as “almost living fossils” Horseshoe crabs aren’t really “living fossils” Evolution of Horseshoe CrabsLarry Moran
November 1, 2015
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