Leslie -Leslie's response didn't say anything about dinosaur-to-bird transitions, but he did discuss whale evolution, Tiktaalik, and my loyalty to the Scripture:
As a Christian who believes that nature and revelation both point to God, I have some questions about your post.
First, why would carbon dating be relevant at all in this discussion? Isochron dating using element pairs such as rubidium-strontium and uranium-lead are now the dominant technique for radiometric dating.
Second, I am puzzled by your statement that there are no transitional forms. For example:
I read, and believed, a lot of the YEC literature for a very long time. When my scientist friends started showing me what scientists have really discovered--and not what the YEC advocates claim the scientists have discovered--I realized that the YEC advocates simply did not understand the science very well.
- Tiktaalik demonstrates a transition from lobe-fin fish to primitive tetrapods.
- Ambulocetus natans is a transitional form between the land-dwelling common ancestor of hippos/whales and today's whales. In fact, this video displays the impressive catalog of transitional forms from Ambulocetus down to today's whales. I would be curious to get your feedback on the video; I found it very enlightening.
- Mei long is an early transitional fossil in the evolutionary sequence from dinosaurs to birds (which includes several transitional forms).
I encourage you to explore the resources I have cited in this comment and in my previous comment. You will probably be tempted to reject them out of hand; I know I was tempted that way when I first encountered similar resources. But as I said before, the testimony of my believing scientist friends, along with the testimony of godly theologians (such as Augustine) who spoke of using science to separate the wheat of God's self-revelation from the chaff of our imperfect human interpretations, has brought me to where I am today. The journey has sometimes been stormy, and it isn't over yet. But I thank God for faithfully guarding and leading me on that journey.
Chris I can appreciate Christians feeling the pressure to somehow reconcile current views on science with scripture by tossing out the book of Genesis. I can assure you that this it not necessary. Secular linguistics admit that Genesis was written to be taken literally and so I must go with that but that doesn't mean we have to check our brains at the church door. Aside from my background in biology, I minored in sedimentology and am grateful for that because it helped to fill the missing links lol in a lot of my discernment about evolution's numerous false teachings and the stretching of scientific arguments to perpetuate the hoax. Even accepting a long age view of the earth there are so many holes in current whale evolution theory that it becomes quite implausible:I was somewhat pressed for time, so I spread my responses out over a few days. I first addressed his statement about social pressure:
1. Limited time for transition The evolution of the whale has previously raised substantial problems because of the extremely abrupt timescale over which it occurred.
Evolutionary Biologist Richard von Sternberg has previously applied the population genetic equations employed in a 2008 paper to argue against the plausibility of the transition happening in such a short period of time. Indeed, the evolution of Dorudon and Basilosaurus (38 mya) from Pakicetus (53 mya) has been previously compressed into a period of less than 15 million years.
Such a transition is a fete of genetic rewiring and it is astonishing that it is presumed to have occurred by Darwinian processes in such a short span of time.
This problem is accentuated when one considers that the majority of anatomical novelties unique to aquatic cetaceans (Pelagiceti) appeared during just a few million years... probably within 1-3 million years.
The equations of population genetics predict that assuming an effective population size of 100,000 individuals per generation, and a generation turnover time of 5 years (according to Richard Sternberg’s calculations and based on equations of population genetics applied in the Durrett and Schmidt paper), that one may reasonably expect two specific coordinated mutations to achieve fixation in the time frame of around 43.3 million years. When one considers the magnitude of the engineering fete, such a scenario is found to be devoid of credibility.
What is required to change in a short period of time?
1. Whales require an intra-abdominal counter current heat exchange system (the testis are inside the body right next to the muscles that generate heat during swimming)
2. They need to possess a ball vertebra because the tail has to move up and down instead of side-to-side
3. They require a re-organisation of kidney tissue to facilitate the intake of salt water.
4. They require a re-orientation of the fetus for giving birth under water.
5. They require a modification of the mammary glands for the nursing of young under water.
6. the forelimbs have to be transformed into flippers.
7. The hindlimbs need to be substantially reduced.
8. They require a special lung surfactant (the lung has to re-expand very rapidly upon coming up to the surface)...on and on it goes.
2. New whale fossil find further upsets evolutionary timeline
The jawbone of an ancient whale found in Antarctica may be the oldest fully aquatic whale yet discovered, Argentine in October 2011
Argentine paleontologist Marcelo Reguero, who led a joint Argentine-Swedish team, said the fossilized archaeocete jawbone found in February 2011 dates back (according to evolutionary reckoning) 49 million years. In evolutionary terms, that’s not far off from the fossils of even older proto-whales from 53 million years ago that have been found in South Asia and other warmer latitudes.
With this new fossil find, dating to 49 million years ago, this means that the first fully aquatic whales now date to around the time when walking whales (Ambulocetus) first appear.
This substantially reduces the window of time in which the Darwinian mechanism has to accomplish truly radical engineering innovations and genetic rewiring to perhaps just five million years or perhaps even less. It also suggests that this fully aquatic whale existed before its previously thought-to-be semi-aquatic archaeocetid ancestors.
3. No biological explanation of sequence
No one knows how a hoofed mammal could have returned to the sea. There exists no biological process, even in theory that could explain how its hooves, legs, and arms could transition into flippers; none to suggest how the dolphins sophisticated sonar evolved; and none to account for how the whale developed a body structure capable of withstanding the extreme pressures of hour-long, mile deep ocean dives. Rather, such claims rest on suspect fossil evidence.
4. Pakicetus inachus was a land creature
Pakicetus inachus consists of a small cranial portion, a few teeth, and a small jaw fragment, yet some how it is described as “remains of whales of early Eocene age.” Upon closer examination of the data, one wonders whythis specimen was suggested to be anything other than a fully-adept land animal.
The fossils were found among “land-mammal fauna,” and “in association with land mammals.” This, the discovery team wrote, “indicates that early Eocene whales may still have spent a significant amount of time on land.” The article went on to concede that the evidence suggests a “continental rather than marine environment for Pakicetus during at least part of its daily or annual life cycle.”
Whats more, no post-cranial skeleton was found, rendering any suggestion that Pakicetus was a whale purely speculative, and actually contrary to cranial evidence. The anatomy of Pakicetus was not whale-like, according to the very fossils upon which such claims are based.
These fossils suggest that “there is no evidence that Pakicetus could hear directionally under water.” Furthermore, the creature was “probably incapable of diving to any significant depth. In terms of function, the auditory mechanism of Pakicetus appears more similar to that of land mammals than it is to any group of extant marine mammals.
”Finally, the size of Pakicetus does not impress one as particularly whale-like: the size of its cranium is estimated at no more than 15 cm wide by 35 cm in length, or no more than approximately 6 inches by 12 inches.
5. Ambulocetus resemble more of seals and seal lions not whales
Interestingly, although the fossils suggest that Ambulocetus might have spent time in water, the species may most closely resemble a type of seal or sea lion. This possibility rests on constant references to seal and sea lion-like functions and anatomy in J.G.M Thewissen announcement.
The fossil indicates that they swam by forcing their feet up and down in a way similar to modern otters. The movements on land probably resembled those of sea lions to some degree. Ambulocetus was an archaeocete whale the size of a male of the sea lion. Ambulocetus had a long tail and thus probably lacked a tail fluke…the back muscles primarily powered the hind limbs as in phocid seals. Propulsion of the hind limbs on land may have been accomplished by extension of the back, reminiscent of the hind limb motions of arctocephaline fur seals. Unlike modern cetaceans, Ambulocetus certainly was able to walk on land, probably in a way similar to modern sea lions or fur seals. In water, it combined aspects of the locomotion of modern seals, otters.
6. More dating problems
One additional problem plagues the whale evolutionary sequence... that it may not be a sequence at all. The Nature article announced the date Pakicetus at between 49 and 52.5 mya, Ambulocetus at between 48.5 and 52 mya, and Rodhocetus at between 46.5 and 49.5 mya. Thus, according to evolutionists' own dating results, the three may well have co-existed for more than half a million years. It is therefore impossible, or very improbable, that the three species could have been part of the same evolutionary sequence. Likewise, Rodhocetus balochistanensis and Artiocetus clavis were dated at approximately 47 mya, suggesting that for reasons of contemporary status, Rodhocetus and Artiocetus were not part of a whale.
7. Misleading presentations
In the past The National Academy of Sciences (NAS) publication teaching about evolution promotes whale evolution as fact and illustrates an evolutionary sequence that includes a land-dwelling Mesonychid, followed by Ambulocetus, Rodhocetus, and Basilosaurus. Even though the scientific literature estimates that Ambulocetus and Rodhocetus had respective lengths of about seven and nine feet, versus Basilosaurus 50-to-70-foot length, the NAS booklet shows all four specimens as being the same size, with not even a footnote explaining that they are drawn out of scale.
Teaching about evolution also shows a perfectly formed, whale-like tail fluke for Rodhocetus, but fails to mention that the drawing is based on an artists interpretation, now known to contradict the direct fossil evidence.
Regarding Tiptaalik this article does a commendable job:
https://answersingenesis.org/e...
Hi Leslie,I then addressed the issue of how we interpret Genesis (i.e., hermeneutics):
I will have to defer the discussion of transitional whale forms and Tiktaalik to a better time. I did want to say that I do not feel any particular pressure to fit in with current science, other than that I have a strong passion to follow the truth. In fact, if social pressure were a factor, I would not discuss evolution and Scripture at all, because the majority of my church is enthusiastically committed to Ken Ham's practice of denouncing the "compromisers" who would prefer "man's fallible beliefs" over God's inerrant and unchanging Word.
(As if we all grew up speaking ancient Hebrew, immersed in ancient Hebrew culture, so there is no need to do any interpretation...)
Pax Christi
Hi Leslie,I then read the Answers in Genesis article on Tiktaalik, analyzed it carefully, and reported back on my findings:
Hope you had a good weekend. Augustine of Hippo, among other church fathers, disagreed with the 24-hour day exegesis of Genesis 1. I won't go into all the reasons why in this comment. The point is that you can strongly adhere to the truths of Genesis while disagreeing with a 24-hour day exegesis of Genesis 1, if the most notable theologian of the early church is to be believed.
If you are interested in following up, you can read me about my faith in Genesis in this post from my blog.
Pax Christi
Hi Leslie,Finally, I reported back on my research on whale evolution:
Hope your Monday is going well!
Let's talk Tiktaalik. Shubin and Daeschler mainly contend that it is a transitional form which:
(1) Displays more tetrapod-like features than earlier lobe-fin fishes (e.g., Panderichthys), but not all of the tetrapod features; and
(2) These tetrapod-like features helped it thrive for a time in a swampy Middle Devonian river delta, and possibly even traverse land for brief periods (similar to today's mudskippers and lungfish).
As an intermediate between earlier lobe-fin fish and later tetrapods, Shubin and Daeschler state that Tiktaalik demonstrates that the transition from lobe-fin fish to tetrapod was occurring in the Middle Devonian.
Against this, Dr. Mitchell's presentation makes 2 main points that I am able to discern:
(1) Tiktaalik is missing some tetrapod features, such as a sacral attachment to the vertebrae or fully developed legs.
(2) There is no proof that Tiptaalik did not primarily or exclusively swim, rather than using its appendages to push on the bottoms of shallow swamps.
How can Dr. Mitchell's 2 points do anything against Shubin and Daeschler's evidence?
(1) Shubin and Daeschler never claimed that Tiktaalik has all the features of tetrapods, so Mitchell's first point (that it does not have all the features of tetrapods) is entirely irrelevant.
(2) Even if Tiktaalik never used its appendages to support body-weight against the swamp bottom, it still exhibits transitional features that would be important to subsequent tetrapods.
Mitchell's second claim is also very inconsistent with the design principles espoused by the YEC movement. Please correct me if I'm wrong, but the YEC movement claims that each species has been designed specially by God with features that help it thrive in its environment. Horses have long legs that are terrifically adapted for running fast, for example; we would be astonished if they didn't use them to run fast. So in an environment with very shallow water, an abundance of land-water boundaries, and abundant food on the shores and water surfaces, you're telling me that a design that is well-adapted for propelling Tiktaalik against the bottom of the swamp bottom was not in fact used that way? It had such a marvelous, well-adapted design, but didn't use it to advantage?
I have often heard YEC proponents encourage listeners to see how wonderfully adaptive the designs of living creatures are--see what wonders God has wrought! I fully agree with that sentiment. But when I, as a devout follower of Christ, want to glorify God with regard to a peculiarly adapted creature that lived 375 million years ago, Answers in Genesis sings a different tune, and claims that there's nothing remarkable about it. It's a shame that AiG is missing an opportunity to glorify God.
Pax Christi
Hi Leslie,
Time to talk whales. The accepted paradigm of whale evolution is that the known fossil species are not actually in a direct lineage, but instead are evolutionary cousins of the actual lineage/tree from the hippo-whale ancestor to today's whales, dolphins, and porpoises. The points that you cited from creationbible.com do not, I'm afraid, withstand careful scrutiny.
(1) Limited transition time: Sternberg's extrapolation of Durrett/Schmidt's paper makes the entirely invalid assumption that all of the mutations are interdependent, and cannot be available for natural selection without all of the others also being simultaneously present. Clearly this is not the case with regard to the 8 cetacean transitions mentioned. If you want further details on the probability calculations, I would be happy to provide an illustration.
Also important is that Sternberg's calculations have never been subject to peer review in the scientific community. (See here.)
(2) The standard theory of whale evolution is not disturbed by recent discoveries of archeocetus, since it was never thought to be in a direct lineage with ambulocetus.
(3) DNA sequencing explanations of cetacean evolution are actually quite powerful; many have been performed and published by undergraduate biology students.
(4) That pakicetus does not have many subsequent whale features is completely unsurprising, given its early placement as a cetacean evolution offshoot. Nothing in creationbible.com's 4th point contradicts anything in the standard evolutionary account.
(5) Ambulocetus has some transitional features on the cetacean chain, but also may have had somewhat divergent locomotion features (more similar to sea lions). Given that it is regarded as a dead-end from the cetacean evolutionary tree, I do not see this as a problem.
(6) Some of the species overlapped in time. Since the standard theory does not regard them as a lineage, time overlap is not a problem.
(7) One diagram was not to scale. The diagram is representing the evolution of skeletal structure, so the scale was selected with the purpose of making the structural evolution visible. Since the scale of the diagram does not misrepresent the structural change, I don't think it's a problem.
Pax Christi
And on that note, the discussion died out. What do you think, dear readers? Is there good reason to think that paleontologists and biologists have fundamentally misunderstood Tiktaalik and cetacean evolution?
Or is it time, perhaps, to accept what the overwhelming majority of the scientific community is saying about evolution, and focus instead on glorifying the God who used a truly ingenious process to produce "endless forms most beautiful and most wonderful"?
Thanks for reading! And please leave a comment if you have any thoughts you'd like to share....
