Uncommon Descent Serving The Intelligent Design Community

Another Day; Another Bad Day for Darwinism


I’ve been saying the OP’s title for years now. And, every day, I read review articles in the like of Phys.Org (they usually get out the articles first!) and, sure enough, there’s an article undermining Darwinian orthodoxy and the neo-Darwinian mechanisms that underpin it.

Here’s today’s latest.

It involves the insect genome and proteins once considered indispensible, hence ‘conserved’, throughout all eukaryotic lineages:

Cell division, the process that ensures equal transmission of genetic information to daughter cells, has been fundamentally conserved for over a billion years of evolution. Considering its ubiquity and essentiality, it is expected that proteins that carry out cell division would also be highly conserved. Challenging this assumption, scientists from Fred Hutchinson Cancer Research Center have found that one of the foundational proteins in cell division, previously shown to be essential in organisms as diverse as yeast, flies and humans, has been surprisingly lost on multiple occasions during insect evolution.

And, then:

It thus appeared that transitions from monocentric to holocentric chromosomes in insects rendered CenH3 non-essential, ultimately leading to its loss in species of insects that comprise 16% of named biodiversity. “Our report completely revises the notions of gene essentiality in a process that is of fundamental importance to all eukaryotic organisms,” added Harmit Malik, Ph.D., researcher in the Basic Sciences division at Fred Hutch. “To find that insect species have replaced the very foundation of centromere definition was quite surprising. It presents a unique opportunity to understand what kind of process may have facilitated this loss.”

Yes, what process? Notice they don’t appeal to neo-Darwinian processes: tacit admission that something really out of the ordinary is at work here.

The Darwinian conundrum this study raises is this: how does an organism go from an “X-type”, “monocentric” chromsome” to a “holocentric” one? Imagine the complexity involved in this change. And, of course, how does one have an “intermediate” form to the “mono-” and “homo-“centric forms when, without chromosome organization, replication would be unthinkable.

Just another day, and just another conundrum for the Darwinists. Exactly how much ‘hope’ and ‘imagination’ do they have? It appears limitless.

P.S. If the scientists would look at their evidence, and then look at it from a “design” perspective, they would gain what I consider to be a very useful insight into all of this. But, alas, they’re Darwinists. And I’m not going to help them out.

Chromosome organization is different between mono- and holocentric chromosomes (for example heterochromatin is more uniformly distributed and not localized to regions around (mono)- centromeres). Holocentric chromosomes essentially means that the kinetic activity (i.e. spindle attachments) cover extensive parts of each chromatid. The underlying sites however, have only been identified in C. elegans so far. Over the short term (right after the transition), I'd expect that the chromosome organization (i.e. synteny) remains conserved and breaks down over the course of evolution because chromosomal fragmentation and fusion is more easily tolerated in holocentric species. I am not sure how DNA replication is different between mono- and holocentric chromosomes. Starbuck
Sensationalism at its finest. This paper does not undermine current evolutionary thought in any way; it is just another piece to the puzzle. In fact, this article only shows that the writers here at UD do not know what they are talking about. First of all, you should try reading the actual scientific paper itself, instead of just the article written by some “phys.org” editor. I can guarantee the original paper was out before the watered down version you read. Anyways, evolution is mentioned throughout the original article, despite its focus being to simply show the existence of these species with holocentric chromosomes. Its only your “phys.org” article that doesn’t appeal to the evolutionary side of this conversation, I would assume because this is how they appeal to readers like you and your friends here. The only thing this paper says is that whereas we once thought cenH3-centromeres were universal to all eukaryotes, we now know that this histone variant is absent in at least four insect lineages and these species form centromeres along the entire length of the chromosome. Given what we already know about the complexity of monocentric chromosome formation (I invite you to do some research on this topic) it doesn’t really surprise me that some organisms have lost this process over the course of evolution and not only remain viable but have thrived for the last 300 million years. If you do decide to do some research, you will also see that conversion from a monocentric to holocentric organism would not be that difficult, as it likely means that the process regulating centromere location has just changed slightly: CenH3 is no longer maintained at a specific site on the DNA molecule. You said: “how does one have an “intermediate” form to the “mono-” and “homo-”centric forms when, without chromosome organization, replication would be unthinkable.” This sentence alone demonstrates that you have no idea what you are talking about. No one is saying that chromosomes are any less organized when holocentric, only that they have multiple centromeres. =) AVS
Speaking of crickets, remember those crickets that evolved silence after being attacked by flies with cricket ears? No, silent ones did NOT evolve, the noisy ones were eaten up fcol. Silent ones were there all along. But how the heck did those flies grow cricket ears? ppolish
Well, you know, we never discuss science here at UD. Mung
Speaking of insects, do I hear crickets chirping? ;) anthropic
Insects aren't really part of the tree of life though. Mung
OT: "Lights Out" S1 (Episode 1) - with Dr. Ann Gauger - video https://www.youtube.com/watch?v=lc0d9HcwgOY&index=1&list=PLk7gMGOsK0fXN1puEUHwS3uocm4SdK9D2 bornagain77
This current finding sort of reminds me of this finding from not too long ago:
A glimpse into nature's looking glass -- to find the genetic code is reassigned: Stop codon varies widely - May 22, 2014 Excerpt: While a few examples of organisms deviating from this canonical code had been serendipitously discovered before, these were widely thought of as very rare evolutionary oddities, absent from most places on Earth and representing a tiny fraction of species. Now, this paradigm has been challenged by the discovery of large numbers of exceptions from the canonical genetic code,,, Approximately 99% of all microbial species on Earth fall in this category, defying culture in the laboratory but profoundly influencing the most significant environmental processes from plant growth and health, to the carbon and other nutrient cycles on land and sea, and even climate processes.,,, "We were surprised to find that an unprecedented number of bacteria in the wild possess these codon reassignments, from "stop" to amino-acid encoding "sense," up to 10 percent of the time in some environments," said Rubin. Another observation the researchers made was that beyond bacteria, these reassignments were also happening in phage, viruses that attack bacterial cells.,,, The punch line, Rubin said, is that the dogma is wrong. "Phage apparently don't really 'care' about the codon usage of the host. http://www.sciencedaily.com/releases/2014/05/140522141422.htm
The reason why deviating from the canonical code is so 'unexpected' to the Darwinian worldview is best xplained by Dawkins himself:
Venter vs. Dawkins on the Tree of Life - and Another Dawkins Whopper - March 2011 Excerpt:,,, But first, let's look at the reason Dawkins gives for why the code must be universal: "The reason is interesting. Any mutation in the genetic code itself (as opposed to mutations in the genes that it encodes) would have an instantly catastrophic effect, not just in one place but throughout the whole organism. If any word in the 64-word dictionary changed its meaning, so that it came to specify a different amino acid, just about every protein in the body would instantaneously change, probably in many places along its length. Unlike an ordinary mutation...this would spell disaster." (2009, p. 409-10) http://www.evolutionnews.org/2011/03/venter_vs_dawkins_on_the_tree_044681.html
Of related note is the humorous video from a few years before in which Venter almost made Dawkins have a cow when Venter denied that common descent was as well supported as Dawkins thought it was:
Dr. Craig Venter Denies Common Descent in front of Richard Dawkins! - video Quote: "I think the tree of life is an artifact of some early scientific studies that aren't really holding up.,, So there is not a tree of life. In fact from our deep sequencing of organisms in the ocean, out of, now we have about 60 million different unique gene sets, we found 12 that look like a very, very deep branching—perhaps fourth domain of life. " - Dr. Craig Venter, American Biologist involved in sequencing the human genome http://www.youtube.com/watch?v=MXrYhINutuI

Leave a Reply