Uncommon Descent Serving The Intelligent Design Community

Researchers: Cichlids are causing a rethink of the “fundamentals of evolution”

arroba Email

Further to PAV’s post on the rayfinned fish with two sets of jaws, here’s what’s said at ScienceDaily:

Given the success of cichlids, understanding the evolution of these two jaws has become an important line of inquiry for biologists. “We’re trying to gain a better understanding of the origins and maintenance of biodiversity,” says Albertson. Researchers have long thought that the two sets of jaws are evolutionarily decoupled and can evolve independently of one another, pushing the boundaries of morphological evolution. However, Conith and Albertson demonstrated that such decoupling does not appear to be the case for cichlids, challenging a quarter-century-old assumption. “What we’ve found is not just that the evolution of the two sets of jaws is linked, but that they’re linked across multiple levels, from genetic to evolutionary,” says Albertson

These findings are a significant step forward in better understanding how evolution works. For instance, many models of evolution theorize both that organisms are constructed from repeated units — digits on your hand or teeth in your mouth — and that these individual units evolve independently from one another. “It is this ‘modularity’ of organisms that is thought to facilitate the evolutionary process,” Albertson notes.

Linked systems are usually thought to lack evolutionary potential. “They just cannot evolve in as many dimensions,” Conith says. This is referred to as an evolutionary constraint, and it plays an important role in shaping biodiversity. Constraints determine what body structures are possible.

Remarkably, this constraint seems to be the key to cichlid’s success by promoting rapid shifts in jaw shapes and feeding ecology, all of which is likely to be an advantage in a dynamic and fluctuating environment, like the East African Rift Valley, where Lake Malawi is located. “The constraint is actually facilitating cichlid evolution, rather than impeding it,” says Conith.

“This tells us that we need to rethink the fundamentals of evolutionary mechanisms,” says Albertson. “Perhaps constraints play a wider role in the evolutionary success of species around the world.”

University of Massachusetts Amherst, “Jaws; or, how an African ray-finned fish is helping to rethink the fundamentals of evolution” at ScienceDaily

Another Principle of evolution out the window… constraints can be advantages after all.

The paper is open access.

Per Physorg in 2017, here is a previous article on Albertson's work with cichlids, (for over 20 years now) where he stresses the importance of epigenetic and/or environmental factors in determining craniofacial bone development in cichlids
Evolutionary biologists identify non-genetic source of species variability - 2017 Excerpt: An unspoken frustration for evolutionary biologists over the past 100 years, says Craig Albertson at the University of Massachusetts Amherst, is that genetics can only account for a small percentage of variation in the physical traits of organisms. Now he reports experimental results on how another factor, a "bizarre behavior" that is part of early cichlid fish larvae's developmental environment, influences later variation in their craniofacial bones. Albertson has studied African cichlid fish for 20 years as a model system for exploring how biodiversity originates and is maintained, with a focus on genetic contributions to species differences. In a new series of experiments with former Ph.D. student Yinan Hu, now a postdoctoral fellow at Boston College, they examined a "vigorous gaping" behavior in larval fish that starts immediately after the cartilaginous lower jaw forms and before bone deposition begins. Results appear in the current early online issue of Proceedings of the Royal Society B.,,, Albertson, an evolutionary geneticist, says, "For over a hundred years, we've been taught that the ability of a system to evolve depends largely on the amount of genetic variation that exists for a trait. What is ignored, or not noted for most traits, is that less than 50 percent of genetic variation can typically be accounted for by genetics." He adds, "Variation in skull shape is highly heritable, so why can we only find genetic variability that accounts for such a small amount of variability in bone development? In my lab we have shifted from elaborating our genetic models to looking more closely at the interaction between genetics and the environment." How the environment influences development is known as epigenetics in its original and broadest meaning, Albertson points out. Coined in the 1940s to mean anything not encoded in the nucleotide sequence, it has narrowed to refer to how the 3D structure of the DNA molecule is modified, he notes. "That meaning is true, but it isn't the only one. We're returning to the original definition.",,, Albertson says, ",,,in 15 years of manipulating the genetics of craniofacial bone development we can account for up to 20 percent of the variability, so it's modest.,,," The geneticist adds, "When I give talks, this is what surprises colleagues the most, that the environmental effect is on par with the genetic effect, and that it is not systemic but highly specific to important bones involved in fish feeding." https://phys.org/news/2017-08-evolutionary-biologists-non-genetic-source-species.html
Thus when Albertson, an evolutionary geneticist with over 20 years experience under his belt, states, via his present 2021 paper, that “This tells us that we need to rethink the fundamentals of evolutionary mechanisms" he is more than qualified to know exactly what he is talking about. And just how radically do we need to "rethink the fundamentals of evolutionary mechanisms"? Well, epigenetic, and/or environmental, factors determining morphological traits are simply not suppose to happen under the "bottom-up" materialistic presuppositions of Darwinian evolution. In fact, as Cornelius Hunter explained, "evolutionists have aggressively and violently opposed (epigenetics) for a century". Yet now, faced with overwhelming evidence to the contrary, they are now trying to rewrite history and pretend as if epigenetics, (i.e. 'top-down' factors determining phenotypic traits), does not directly contradict their 'bottom-up' reductive materialistic theory of Darwinian evolution.
Michael Skinner on Epigenetics: Stage Three Alert - Cornelius Hunter - December 4, 2016 Excerpt: Skinner’s Aeon article provides an excellent rundown of findings, both old and new, that confirm and elucidate what evolutionists have aggressively and violently opposed for a century: that epigenetics is not only real, but significant in causing long-term biological change. Natural selection plays no role in this process.,,, What Skinner and the evolutionists don't tell you is that in light of their theory, none of this makes sense. With epigenetics the biological variation evolution needs is not natural. It is not the mere consequence of biophysics -- radiation, toxins, or other mishaps causing DNA mutations. Rather, it is a biological control system. It is not simple mistakes, but complex mechanisms. It is not random, but directed. It is not slow, but rapid. It is not a single mutation that is selected, but simultaneous changes across the population. This is not evolution. As Skinner inconveniently realizes, such epigenetics are found across a wide range of species. They are widely conserved and, for evolution, this is yet more bad news. . It means the incredible epigenetics mechanisms must have, somehow, arisen very early in the history of evolution. What the evolutionists don’t admit is that epigenetics contradicts evolutionary theory. Not only must such incredibly complex mechanisms have evolved early on, and not only must they have arisen from chance mutation events, and so not only must evolution have created evolution, but they would have persisted in spite of any fitness advantage. The whole notion of evolution is that natural selection saves the day by directing the blind, chance mutations. Setting aside the silliness of this idea, the problem with epigenetic mechanisms is that if they were to arise from chance (and “oh what a big if”), then mutations would not increase the organism’s fitness. Epigenetic mechanisms are helpful at some future, unknown, time when the environmental challenge finally presents itself. They are useless when they initially arise, and so would not be preserved by evolution’s mythical natural selection. Of course evolutionists will contrive yet more complex just-so stories to explain how epigenetics mechanisms arose from pre-existing parts used for other purposes (the ridiculous co-adaptation argument), and about how they just happened to provide some other functions so as to improve fitness. Skinner’s presentation of how to integrate epigenetics with evolution is entirely gratuitous. He has empirical evidence for the former, and dogma for the latter. There is no scientific need for the addition of evolution — it is a multiplied entity and is gratuitous. Yet Skinner needs it.,,, http://www.evolutionnews.org/2016/12/michael_skinner103338.html
Perhaps that is why Bob O'H refused to honestly address Albertson's paper yesterday, (and tried to focus on the minor issue of PaV inappropriately citing Albertson's paper), Epigenetics is simply a deadly 'third rail' for Darwinists to touch in that epigenetics directly contradicts what Darwinists have been 'aggressively' claiming to the contrary for over a century. bornagain77
As to their claim that Cichlids, and fish in general, evolved, well, like everything else in Darwinian thought, their claim is found to be severely wanting of any confirming empirical evidence. Dr. Arthur Jones, who did his Ph.D. thesis in biology on cichlids, "found the cichlids to be an unmistakably natural group, a created kind. The more I worked with these fish the clearer my recognition of “cichlidness” became and the more distinct they seemed from all the “similar” fishes I studied."
"For all the diversity of species, I found the cichlids to be an unmistakably natural group, a created kind. The more I worked with these fish the clearer my recognition of “cichlidness” became and the more distinct they seemed from all the “similar” fishes I studied. Conversations at conferences and literature searches confirmed that this was the common experience of experts in every area of systematic biology. Distinct kinds really are there and the experts know it to be so. – On a wider canvas, fossils provided no comfort to evolutionists. All fish, living and fossil, belong to distinct kinds; “links” are decidedly missing." Dr. Arthur Jones - did his Ph.D. thesis in biology on cichlids - Fish, Fossils and Evolution - Cichlids at 29:00 minute mark (many examples of repeated morphology in cichlids) - video http://edinburghcreationgroup.org/video/14
There is simply no evidence in the fossil record that fish ever evolved from anything. Fish just appear suddenly in the fossil record with no evidence of transition from anything else.
Fish Evolution vs. The Actual Fossil Evidence – video (17:30 minute mark and 20:50 minute mark) https://www.youtube.com/watch?v=yQNrQKVVMKw&feature=youtu.be&t=1050 The Fossils Still Say No: The Mystery of Jawed Vertebrates – January 2021 Excerpt: Despite many fossil discoveries of numerous vertebrate fish over the past several hundred years, not a single transitional form has been found showing how jawed fish could have developed from jawless ancestors. In fact, numerous types of jawed fish appear suddenly in the rock record alongside new types of jawless fish. https://www.icr.org/article/the-fossils-still-say-no-mystery-jawed-vertebrates
Moreover, finding vertebrate fish in the Cambrian explosion makes their sudden appearance in the fossil record exponentially harder for Darwinists to try to 'explain away' with their (evidence-free) just-so stories.
Challenging Fossil of a Little Fish Excerpt: In the Nature article announcing his latest findings, Jun-Yuan Chen and his colleagues reported dryly that the ancient (530-million-year-old) fish “will add to the debate on the evolutionary transition from invertebrate to vertebrate.” But the new fossils have become nothing less than a challenge to the theory of evolution in the hands of Chen, a professor at the Nanjing Institute of Paleontology and Geology. Chen argues that the emergence of such a sophisticated creature at so early a date shows that modern life forms burst on the scene suddenly, rather than through any gradual process. According to Chen, the conventional forces of evolution can’t account for the speed, the breadth, and one-time nature of “the Cambrian explosion,” a geologic moment more than 500 million years ago when virtually all the major animal groups first appear in the fossil record.,,, "In Chen’s view, his evidence supports a history of life that runs opposite to the standard evolutionary tree diagrams, a progression he calls top-down evolution." (i.e. disparity preceding diversity) Jun-Yuan Chen is professor at the Nanjing Institute of Paleontology and Geology https://www.fredheeren.com/boston.htm Cambrian Explosion Included Vertebrate Fish - 2014 Excerpt: Conway Morris’s paper focuses on one amazing critter called Metaspriggina found in abundance at Marble Canyon with exquisite preservation. He says it possesses all the traits of a vertebrate fish: muscles that allow it to move side-to-side, gills, a skull, blood vessels, and paired camera-like eyes. The 100 or so new specimens are so detailed, they confirm that this animal was not just a “basal chordate” but a real vertebrate—a real fish. In some ways, it was more advanced than lampreys (a jawless fish). There are flatfish today that look something like this one. In short, the paper removes all doubt that vertebrate fish were present in the Lower Cambrian—the time of the Cambrian explosion. Moreover, no primitive ancestors of this species have ever been reported. There’s another surprise: it looks very similar to two species reported earlier in the Chinese Chengjiang strata (8/21/02, 1/30/03) whose characterization as vertebrates had been controversial. No longer: Metaspriggina now confirms that the Chinese species were also vertebrate fish. And get this: finding plenty of them in Canada means they spanned the globe already! Conway Morris calls them “cosmopolitan”—world travelers. https://crev.info/2014/08/cambrian-explosion-included-vertebrate-fish/
Also of note, 'constraints' are a far bigger problem for Darwinists than the paper in the OP indicated.
K´necting The Dots: Modeling Functional Integration In Biological Systems - June 11, 2010 Excerpt: “If an engineer modifies the length of the piston rods in an internal combustion engine, but does not modify the crankshaft accordingly, the engine won’t start. Similarly, processes of development are so tightly integrated temporally and spatially that one change early in development will require a host of other coordinated changes in separate but functionally interrelated developmental processes downstream” (1) https://uncommondesc.wpengine.com/intelligent-design/k%C2%B4necting-the-dots-modeling-functional-integration-in-biological-systems/ Evolution machine: Genetic engineering on fast forward - June 2011 Excerpt: Yet changing even a handful of genes takes huge amounts of time and money. For instance, a yeast engineered to churn out the antimalarial drug artemisinin has been hailed as one of the great success stories of synthetic biology. However, it took 150 person-years and cost $25 million to add or tweak around a dozen genes - and commercial production has yet to begin. http://www.newscientist.com/article/mg21028181.700-evolution-machine-genetic-engineering-on-fast-forward.html?full=true “This is the issue I have with neo-Darwinists: They teach that what is generating novelty is the accumulation of random mutations in DNA, in a direction set by natural selection. If you want bigger eggs, you keep selecting the hens that are laying the biggest eggs, and you get bigger and bigger eggs. But you also get hens with defective feathers and wobbly legs. Natural selection eliminates and maybe maintains, but it doesn’t create….” (Lynn Margulis Says She’s Not Controversial, She’s Right,” Discover Magazine, p. 68 (April, 2011) "The real number of variations is lesser than expected,,. There are no blue-eyed Drosophila, no viviparous birds or turtles, no hexapod mammals, etc. Such observations provoke non-Darwinian evolutionary concepts. Darwin tried rather unsuccessfully to solve the problem of the contradictions between his model of random variability and the existence of constraints. He tried to hide this complication citing abundant facts on other phenomena. The authors of the modern versions of Darwinism followed this strategy, allowing the question to persist. ...However, he was forced to admit some cases where creating anything humans may wish for was impossible. For example, when the English farmers decided to get cows with thick hams, they soon abandoned this attempt since they perished too frequently during delivery. Evidently such cases provoked an idea on the limitations to variability... [If you have the time, read all of the following paper, which concludes] The problem of the constraints on variation was not solved neither within the framework of the proper Darwin’s theory, nor within the framework of modern Darwinism." (IGOR POPOV, THE PROBLEM OF CONSTRAINTS ON VARIATION, FROM DARWIN TO THE PRESENT, 2009, http://ludus-vitalis.org/html/textos/32/32-11_popov.pdf

Leave a Reply