Molecular Genetics of Whale Evolution


(George) #97

@scd

The “predictions” usually mentioned are not in presented in the way you are presenting. For example, because of the sudden nature of a multi-branched part of the whale “tree” that had baleen instead of teeth.
In a world of special creation, obviously God specifically made these whales without teeth, right?

Evolutionists predicted that we would find traces of “teeth” in the genetic signature of these baleen whales.
But that would be silly, right? Why would God put useless teeth genes in whales beautifully designed to use baleen?

And yet … the prediction that teeth were genetically incipient was predicted and confirmed!:

Evolution: A Theory with Bite
“If indeed modern whales are descended from ancestral, four-limbed, terrestrial ancestors, then those ancestors, like mammals in general, had teeth. Modern toothed whales (order Odontoceti) have retained those teeth to the present day, but baleen whales have adopted a new way of life as filter-feeders.”

“Researchers were curious to see if traces of a “toothed past” could be found in the genomes of modern baleen whales, so they went hunting for remnants of genes devoted to making teeth. Such defective gene remnants would be examples of pseudogenes, and we have discussed pseudogenes previously in this series.”

“[While pseudogenes in and of themselves are powerful evidence for evolution, pseudogenes that are “out of place” are especially so. One such example we have seen before is the human vitellogenin pseudogene, the remains of a gene used for yolk production in egg-laying organisms found in the exact location in the genome that evolution would predict for it. As mammals that receive embryonic nourishment through a placenta, we have no need of egg-yolk genes.]”

“Similarly, baleen whales have no need for genes responsible for making teeth, and finding the remnants of such genes would make a strong case for an evolutionary origin of baleen whales as the modified descendents of toothed whale ancestors.”

“Some of the genes known to be used in all mammals for tooth formation were the obvious candidate genes to start with: the products of the ameloblastin, amelogenin, and enamelin genes are all used in the formation of tooth enamel, the hardest structure in the vertebrate skeleton. Researchers went looking for these genes in several Mysticete (i.e. toothless whale) species. The results showed that all the species studied did indeed have these three genes present as pseudogenes…”

"Finding these genes as pseudogenes in toothless whales was exactly what evolution predicted, but there was a catch: none of the mutations that removed the functions of these three genes were shared between different species, suggesting that these genes lost their function independently in the species studied."

“This finding was at odds with data from the fossil record, which suggested that teeth were lost only once, and early in the lineage leading to all modern toothless whales. So, the researchers seemed to have two lines of evidence that at face value contradicted each other. The fossil record suggested that tooth loss occurred once in the common ancestor of all toothless whales, but these three genes seemed to have been inactivated independently, several times over, suggesting that loss of teeth should be happening later in Mysticete evolution, and more than once.”

“One proposed explanation for the apparent discrepancy (among several put forward) was to predict that a fourth gene required for enamel formation was lost early in Mysticete evolution. The loss of any one gene necessary for forming enamel would be enough to prevent the process altogether. In this case, the loss of this fourth gene would prevent tooth enamel from forming, even though the genetic sequences of the other three enamel genes would still be intact. Once enamel function was lost, random mutations in the remaining enamel genes could then accumulate later in Mysticete evolution after speciation in this group was already underway.”

“To test this hypothesis, the research group went hunting for other enamel genes in toothless whales. The smoking gun for tooth loss in Mysticetes turned out to be exactly what was predicted: a fourth gene, necessary for enamel production, and mutated with the same inactivating mutation in all modern toothless whales. The gene in question, named enamelysin, was destroyed when a mobile genetic element called a SINE transposon inserted into it, breaking it into two halves and removing its function: [see image below]”

[ ^ Be sure to click on image to enlarge the text for easier reading! ]


(George) #98

@scd

By the way, a 300% error bar means “3 times”… not “300 times”.


(Jon Garvey) #99

@cwhenderson

This is evidently true, but then wouldn’t it also be an argument against Francis Collins assertion that “after the first cell, no special supernatural intervention was required”?

The case for secular versions of evolution (see Patrick!) is that random changes can be shown to be all that is needed for evolution to do what it has done (that “random” being left undefined and probably incoherent, but including mainly unknown but law-based changes).

The atheist accepts the same, demonstrable laws of nature as the theistic evolutionist, so if (as per Deb Haarsma and others) evolution is believed to be driven entirely, or nearly entirely, by divinely designed laws, that too is theoretically demonstrable, and evolution would then prove to be guided by the laws, the only difference between the atheist and the Christian being whether the laws are a brute undesigned fact or a divine provision - randomness would not enter the question at all.

If (as most biologists following Monod seem to believe) evolution is not entirely lawlike, but contingent, then there would arise a true competetion between the powers attributed to chance and the powers of real-time divine choices. In that case, given the rarity of beneficial mutations, there would seem to be some demonstrable loading of the mutational device in delivering so much help in so short a time to Mr Whale.

Of course, if evolution only works as it does because it is guided, then guidance is entering the empirical realm against Epicurean chance.


(Guy Coe) #100

Thanks for stating this so eloquently, and even elegantly, @jongarvey . This is, in fact, the point I thought would be obvious when I raised this question in the first place. Cheers! Evolution, while demonstrably present, is simply not enough.


#101

incorrect. since their split happened a long time ago evolution doesnt predict anything about that. if we were find no such pseudogene evolution will be just fine. and its also true for the rest “predictions”.


(George) #102

@scd,

Please don’t ask me to reply to your posts. You do not understand general principles of science well enough to even discuss these points with you.


#103

why gbrooks? what is wrong with what i said? i just said that evolution doesnt predict that we will find such a pseudogene. for instance: human loss about 50 genes in about 5-6 my. most of them have left no exons. so if we are talking about 20-30 my old pseudogene it will be unlikely to find such a pseudogene even according to evolution.


(George) #104

There are dozens of perfectly clear articles out there … pointing out that because several different lineages of baleen whales exist … with their unique “tooth constellation” of genes apparently intact.

Knowing how Natural Selection works in nested hierarchies, the prediction was made that we would eventually find the gene that “broke” - - higher up in the causal chain, so that regardless of the “tooth constellation”, the “tooth constellation” would never be triggered.

And this prediction turned out to be correct.

You either understand this or you don’t. Based on your post, you certainly didn’t understand the point being made - - which is a fundamental PILLAR of natural selection’s interaction with a given population’s gene pool.

I don’t mind offering remedial information and insights… but not if the party is intentionally and willfully mis-communicating the very nature of how science is conducted.


#105

but if we were not find this gene we c an always say that this loss happen several times at several lineages.


(George) #106

Great news! At @swamidass’ encouragement, I share a new BioLogos factoid over here at Peaceful Science:

@T.j_Runyon, over on the BioLogos side of the Universe, just corrected an error that the “Walking Whales” article promulgated…

He writes:
“…First this [dating comes from…] the press release. The later paper dated it at 40-46mya which is consistent with other Basilosaurids worldwide. But let’s say it is 49mya, all this would mean is there are likely older Pakecetids. This is a real possibility. There aren’t any Paleocene Indian mammal localities.
Note: I’ve worked on Basilosaurids and love discussing them.”
[ ^^ And we at Peaceful Science love that you love discussing them! ]

I wrote:
“Now THAT is frustrating … the press release had the aging incorrect?! Arghhh.”

@T.j_Runyon11m replied:
“Well that was the researcher’s first date. But their later publication showed them to be incorrect.”

Many thanks, T.J. !


(George) #107

The link to the finished article… provided by @T.j_Runyon:

T.j_Runyon15m
The actual paper for those interested:

http://www.bioone.org/doi/abs/10.5710/AMGH.02.02.2016.2922

In summary, considering that 87Sr/86Sr ratios provided for TELM 4 might be biased (because of potential reworking and oscillation of the marine Sr isotope curve during the Eocene), we interpret the age of the horizon that produced MLP 11-II-21-3 (i.e., TELM 4) as early middle Eocene (~46–40 Ma; middle Lutetian to early Bartonian based on ICS International Chronostratigraphic Chart 2015; Cohen et al., 2013) and follow the most recent chronostratigraphic interpretation for the La Meseta Formation.


(S. Joshua Swamidass) #108

A fairly good video summarizing the evidence that encourages even some YECs to conclude that whales evolved from land mammals.