Erica (@GutsickGibbon) is doing a great live-stream series with a creationist Will Duffy (idk if he has an account here?). Of course, Will does not accept evolution, but he deserves the respect for being willing to sit down and listen to… basically… Erica giving hours of lectures on evolution, mostly focusing on the fossil record. The latest episode was focused on bird evolution:
The previous episode was focused on whale evolution, so Will Duffy prepared a few counter-points which he presented at the beginning of the live stream [18:29 - 28:25] .
A few notes for Erika
But first, I also have a couple of notes for @GutsickGibbon. I still think the presentations are excellent, but I am concerned about the “linear” depictions of evolution, e.g. @1:12:52 regarding horse evolution.
Best to emphasize the branching pattern to avoid the impression of an orthogenic “march of progress”. These are good examples:
Also, I find the bracket diagrams like this ( at 1:40:31) to be very confusing.
It’s almost like a phylogenetic diagram turned 90 degrees to the left, relative to what it is supposed to be with respect to the geological timescale. I understand Erika wanted to show the time-ranges of these clades, but if someone does not understand the context, it may look like the last common ancestor of Neornithes lived in the middle of the Cenozoic. A better way to illustrate this is using vertical bars or lines, not with brackets. See example below (source).
Now moving on to Will Duffy’s points.
Why does nobody talk about Werner?
[16:20] after our last session on whale evolution last month, I decided to do something that I’ve been intentionally trying to avoid doing, and that is I reached out to a creationist on the topic. Now, who did I reach out to? I reached out to Dr. Carl Werner. Um, I don’t know if many people are going to be familiar with who Dr. Carl Werner is. There’s a reason I reached out to him and that is because, I know who he’s interviewed and what kind of work he has seen on fossils.
I will say this, Erica, and this is not directed at you at all. There’s a very strange… because because I reached out to him, I went to kind of the debunking channels. I went to your channel as well to find out if anybody’s talking about Carl Werner and could find almost no mentions of him. And for some reason, uh, you are definitely on the very bottom end of this. There’s a strange obsession in the creationist debunking world with Kent Hovind. And so I don’t exactly know what that is, but I there was there was no limit of videos about Kent Hovind, which I don’t understand, and nothing about Dr. Carl Werner.
Will Duffy
Yes, I was also shocked to see someone using Carl Werner’s arguments from “The Grand Experiment” from 2007. I am starting to feel old. Okay… okay… I should calm down. I shouldn’t bash on someone for bringing up such ancient PRATTs. It may be the case that this is the only information they know on the subject, but this does explain why Will Duffy was unable to find anybody talking about Werner’s arguments… they are old!.. any debunking video that mentions his arguments are also old.
Although as Erika later brings up, Joel Duff did make a couple of response videos to Werner a few years ago, mostly focusing on Werner’s mistaken belief that Castorocauda is a beaver that lived during the time of the dinosaurs. It’s not a beaver… Castorocauda is not even a rodent. It’s not even a placental mammal. It’s a Docodont, which were a group of mammal-relatives that are outside the crown-group of mammals that are alive today. To put this in more simple terms, calling a Platypus a beaver is more accurate than calling Castorocauda a beaver. I also re-discovered this old blog post from 2015 that debunks Werner on his claims about whale evolution.
That’s not to justify the fact that lot’s of people make debunking videos on Kent Hovind. He is an easy target and a lolz cow for all the wrong reasons. EDIT: @Rumraket makes fair points below about how Kent Hovind is still seen and propped up as an authority figure by other creationists.
Rodhocetus
The paper that first described Rodhocetus was published in 1994 which shows this skeletal image:
Rodhocetus is portrayed on the top (a) and it is compared to a terrestrial mammal called Pachyaena (a mesonychid) on the bottom. Back in the 1990s, most paleontologists thought that whales descended from Mesonychids, a group of extinct, carnivorous, hoofed mammals related to - but not part of - the even-toed hoofed mammals (Artiodactyla). This will also be relevant later on, but let’s put a pin on Mesonychids for now let’s just note that the original paper concludes that Rodhocetus is a transitional fossil based on a mix of primitive, terrestrial mammal and derived, aquatic whale characteristics that are directly observable (emphasis mine):
[Rodhocetus] is an early archaeocete that retains high neural spines on anterior thoracics
and a pelvis articulating directly with the sacrum. These are primitive characteristics of mammals that support their weight on land, and both suggest that Rodhocetus or an immediate predecessor was still partly terrestrial. At the same time, cervicals are short, enhancing rigidity of the anterior body, sacrals are large but unfused, enhancing power and flexibility, and the femur is reduced, streamlining the lumbocaudal trunk. These are derived characteristics of later archaeocetes and modern whales associated with aquatic locomotion. Thus the morphology of Rodhocetus is intermediate, as might be expected of a transitional form evolving from land to sea.
The authors also note specific skeletal features found in whales (e.g. lack of fused sacral vertebrae) which indicates that the flexible spine was used for swimming. They saw this as a possible indication that the tail was also used, perhaps with flukes, but the authors to their credit stressed that the caudal (tail) vertebrae are not present in the fossil specimen, and that their hypothesis of a tail with flukes can be tested with more complete fossils (emphasis mine).
Most modern whales have robust lumbar and proximal caudal centra, and all lack fusion of sacral vertebrae, making the lumbocaudal column seamlessly flexible. High dorsal neural spines and long ventral chevrons limit vertebral excursion but provide leverage for powerful axial and abdominal muscles. Rodhocetus has all of these functional features. This indicates that the characteristic cetacean mode of swimming by dorsoventral oscillation of a heavily muscled tail evolved within the first three million years or so of the appearance of archaeocetes. Terminal caudals are lacking in the type specimen of Rodhocetus and we cannot assess the possible presence of a caudal fluke, but it is reasonable to expect development of a fluke to coincide with shortening of the neck, flexibility of the sacrum and reduction of hind limbs first observed in Rodhocetus. This idea can be tested when a more complete tail of Rodhocetus is found.
Based on this description, palaeoartists depicted Rodhocetus like this:
Moving forward to 2001, Gingrech and his colleagues published another paper describing more specimens of Rodhocetus. The paper included this composite restoration:
Now the limbs are present, which did not have flippers unlike the previous reconstruction. Although, the hands and feet were likely webbed. Even though the end of the tail was still not found (note the hatched lines), the authors retracted their hypothesized fluked-tail due to the lack of robust flippers (emphasis mine).
If the hands and feet were webbed as inferred here, then Rodhocetus was probably capable of quadrupedal paddling as well as pelvic paddling. The robust tail of Rodhocetus suggests that caudal undulation was important as well, especially while moving beneath the water surface. (Note that the length of the tail is not known.) The forelimbs and hands could not be extended as broad pectoral flippers, which would be required to control recoil from undulation or oscillation of a caudal fluke (38); hence, it is doubtful that Rodhocetus had such a fluke.
And later in 2003, Gingerich (sole authors this time) noted that Rhodocetus probably had fur (emphasis mine).
Discovery that Rodhocetus has trunk and limb proportions like a desman implies, in the
context of Fish’s model, that it was at an alternate-pelvic-paddling stage of drag-based pro-
pulsion, swimming mostly at the surface, insulated and buoyed by non-wettable fur, and incapable of deep diving.
Thus, contemporary and more accurate depictions of Rodhocetus look more like this:
So, to summarize… Rodhocetus was first described based on an incomplete fossil in 1994. However, based on the features that were directly observable, having both traits of terrestrial mammals and traits of aquatic whales, it was identified as a transitional fossil. That conclusion has not changed. What did change was the details of its limbs and tail, and exactly how it moved in the water. It was not as specialized for swimming (with flippers and flukes) as previously hypothesized, and the scientists were fully open and upfront on this from the beginning. The artistic depictions also change along with it, but - of course - these updates lagged behind the science. So it is also a bit unfair to blame the artists, especially way back in 2001 when scientists were just publishing the update.
This is exactly how science works, but - for some reason - some creationists really don’t like when scientists are honest and change their minds in light of new evidence. Instead, they see this as fraudulent because they see everything backwards, and then use out-dated artistic depictions to jump to the conclusion that it must all be wrong. More specifically, Carl Werner complained about the old depiction of Rodhocetus with flukes and flippers, while the first specimen lacked the limbs and tails, and is all surprised when Gingerich makes a “stunning admission” on this fact.
I went to the museum to see the actual fossils and film the interview. When I arrived, I noticed that the fossils of the most spectacular aspect of Rodhocetus were missing. There were no fossils of the arms and tail yet they had flippers and a whale’s tail on the diagram. When I pointed this out to Dr. Gingerich in the interview, he retracted his claim that Rodhocetus had flippers or a fluke. His admission in this interview was simply stunning. My confidence was shaken.
Dr Werner, recounting his interview with Gingerich in 2001
But none of this would be “stunning” if you read the 1994 paper, which Werner should have done so. If he did not, that’s just outright laziness, which would be odd given the fact that Werner took the time to visit the museum and have an in-person interview with Gingerich. If Werner did read the paper, then he is just blatantly lying to make it look like that Gingerich was being dishonest. More importantly, none of this changes the fact that Rodhocetus is a transitional fossil possessing characteristics of both terrestrial mammals and aquatic whales as noted at the beginning. Werner does not even make an attempt to address this fact.
Ambulocetus
The 1994 paper by Thewissen et al. conclude that Ambulocetus was a transitional fossil based on numerous indications that it could move on land, and the presence of cetacean (whale) traits:
Ambulocetus is clearly a cetacean: it has an inflated ectotympanic that is poorly attached to the skull and bears a sigmoid process, reduced zygomatic arch, long narrow muzzle, broad supraorbital process, and teeth that resemble those of other archaeocetes, the paraphyletic stem group of cetaceans.
Below is the image they provide. The dotted grey parts were found, the white parts were missing. The A and B images shows different body positions while standing on land and in the water respectively.
This image may be more clear to some (dark parts were found):
The authors did not hypothesize on the probable position of the nasal openings, nor the presence of a blowhole, and none of their conclusions were based on this feature. So… as you may guess… creationists made a big deal about something that is not relevant to this fossil’s status as a transitional fossil.
But even if we were to put that fact aside, the complaint about the location of the nasal openings is very odd. Most reconstructions depict Ambulocetus with nasal openings very close to the tip of the snout, but - somehow - this still counts as a “blowhole”? Even Will Duffy does this at 22:54 minutes, claiming that
Ambulocetus is portrayed as a walking whale with a blowhole.
Will Duffy also claims that…
without the blowhole, the skeleton would not look like a whale at all.
Which is completely false, given the whale traits described by Thewissen et al. 1994 as previously noted. Furthermore, the so-called “blowhole” that he points to on this slide is near the tip of the snout as you can see here.
I don’t think you can call this a blowhole, but let’s assume that Duffy is right on this, that this skeleton depicts a blowhole. Then to be consistent, Will Duffy must also accept that Rodhocetus (discussed in the previous section) possesses a blowhole as well, since its nasal openings are positioned above the upper-canines. In contrast, the nasal openings of Ambulocetus in this skeletal reconstruction are positioned a bit in front of the upper-canines.
Next, Will Duffy discusses traits that are relevant. The auditory bulla, specifically the tympanic bone (the bone that includes the inner ear). Duffy claims that the tympanic has “no visible cavity” and “no clear sigmoid process”.
The lack of a visible cavity is explained by the fact that it is filled with sedimentary matrix, which has not been removed, probably because removing this will make it very fragile. But the cavity HAS to be there, since that is where the inner ear is located. Or else you would have to suggest that Ambulocetus does not have an inner ear. About the sigmoid process… it is also there. Thewissen et al. 1994 show it in their image below (labeled si in the top left corner).
I think Duffy made the mistake here. He mistakenly claimed that the sigmoid process is absent (or no “clear” sigmoid process), while he meant to repeat Werner’s claim that the sigmoid process of the fossil is not specifically ‘finger-like’, like those seen in modern whales. But regardless, the fact it is not ‘finger-like’ is not relevant to the conclusions made by Thewissen et al. 1994.
Next, Duffy gives a quote from Gingerich stating that Ambulocetus likely was not part of the “main line” because of its unusual specializations.
..and… so what? The claim is not that Ambulocetus was a direct ancestor to anything alive to day. If there is one thing I want a creationist to learn first and foremost when discussing transitional fossils, it is the following: TRANSITIONAL ≠ ANCESTRAL. Most transitional species are taken to be cousins, not direct ancestors, except in a few cases where enough evidence is available that makes the direct ancestral relationship plausible. But Ambulocetus probably was part of a side-branch which did not lead to whales alive today. In fact, there were lot’s of different lineages of cetaceans which lived alongside each other, and this is completely expected since evolution is a branching process, not a linear series of “progress”. Image below from this source. Note how the ranges of Ambulocetidae (the family that includes Ambulocetus) overlaps with that of other groups.
Pakicetus
First described by Gingerich & Russel in 1981 and Gingerich et al. 1983. Both papers are clear that no remains were found beyond the skull, and only parts of the skull was found. Here is an illustration that the paper includes:
The few features that the scientists could observe did indicate an affinity to whales. As you may guess, one of these were the involucrum of the auditory bulla, which is unique to whales, but also the triangular shaped teeth that were similar to eocene whales like Protocetus. Based these and other whale traits, the artists speculated that it was aquatic like all other whale relatives (no terrestrial whale relative was known at this time). That is the reason for the cover of the April 22, 1983 issue of Science magazine:
Again, this was not an unreasonable guess at the time in 1983. But while creationists continue to complain about this, scientists (and palaeoartists for that matter) have long since moved on. Thewissen et. al 2001 described more complete fossil remains which showed that Pakicetus was actually a walking whale. So, something which was first identified to be a whale(-relative) later turned out to be also terrestrial. How does this help creationists exactly? Why would we expect to find terrestrial whales, if not for the predictions based on common ancestry?
Thewissen et al. 2001 did conclude that:
The features of the skull indicate that pakicetids were terrestrial, and the locomotor skeleton displays running adaptations. Some features of the sense organs of pakicetids are also found in aquatic mammals, but they do not necessarily imply life in water. Pakicetids were terrestrial mammals, no more amphibious than a tapir.
However, Gingerich 2003 disagreed, and argued that Pakicetus was more aquatic compared to a tapir:
Isolated postcranial elements attributed to Pakicetus attocki have recently been described and compared with Dorudon and other basilosaurids (but not with protocetids), leading to the the conclusion that ‘‘pakicetids were terrestrial mammals, no more amphibious than a tapir’’ (Thewissen et al. 2001: p. 278). The 14 pakicetid postcranial elements illustrated in detail (Thewissen et al. 2001: Fig. 1) are all plausibly archaeocete because they differ little from comparable elements of Rodhocetus and other early protocetids (Gingerich et al. 1994, 2001a). Most interesting are two partial innominates that together show the ilium to have been shorter than the ischium (Thewissen et al. 2001: p. 277 and Fig. 1n). Length of the ilium is the most important determinant of the PC-II score reflecting aquatic adaptation (Tables 6, 7, Figs. 3–6), and an innominate with a short ilium implies that Pakicetus was much more aquatic than a tapir.
Gingerich was corroborated by Madar 2007 showing features of the post-cranial skeleton indicating adaptations to aquatic lifestyles, and not for running.
Genetics of whale evolution
The last point Will Duffy discusses is regarding the fact that genetics point to hippos being the closest living relatives to whales. To counter this, Duffy brings up quotes from Gingerich and Domning
I am not sure how old these quotes are, but I can already guess that this is probably due to the Mesonychid thing which I aluded to before. For a long time, palaeontologists thought that whales desceded from Mesonychids: archaic mammals that were hoofed and also carnivorous. Mesonychids are closely related to the even-toed ungulates (Artiodactyls), but Mesonychids were not part of Artiodactyla. But molecular evidence continued to indicate that whales belong within the Artiodactyls, specifically with hippos being the closest living relatives of whales.
Palaeontologists did not accept this hypothesis initially, but that all changed in the early 2000s when fossils of cetaceans were discovered which possess the ‘double-pulley’ astragalus (an ankle bone). This feature is unique to Artiodactyls. After this discovery, palaeontologists agreed with the results of molecular phylogenetics .
There is also the issue of herbivory vs carnivory. Except for the omnivorous pigs and peccaries, all Artiodactyls are herbivores, but many do consume a surprising amount of meat. Hippos will also occasionally eat from a carcass during times of need. Furthermore, when were are talking about the ancestors of whales, were are not talking about any of the artiodactyls alive today. Most of the living artiodactyls are very specialized grazers, which thrived after the rise of grassland ecosystems. In contrast, many of the early archaic ungulates were carnivores or omnivores, including the early members of artiodactyls. A good example are the Entelodontids, which are often called ‘hell-pigs’ or ‘terminator-pigs’, which were once thought to be relatives of pigs, but most recent studies put them closer to the whale+hippo group.
Related to this is the second quote that Will Duffy provides:
It’s almost like Domning is responding to the claim that whales descended from hippos, which is not the actual position held by scientists. Whales and hippos are each other’s closest ‘cousins’. The whale group (Cetacea), if you include the terrestrial members as well, go all the way back to the early eocene, fully aquatic Cetacea go back to the middle eocene. The ‘hippos’ in the narrow sense are from the Miocene, but their extinct relatives called ‘Anthracotheres’ also go back into the Eocene, but not as early as the earliest Cetaceans.
FIN