Science is the collection and documentation of observable facts, and an ongoing discussion about how those facts can be best linked together. Though Sternberg is trained in science and may be capable of doing good work elsewhere, in this instance he failed to make a legitimate scientific case for his conclusion.
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One of the earliest fossil creatures accepted as a link to modern whales is Pakicetus attoki, bones of which date back to between 58 and 42 million year ago. The species had 4 legs and certainly walked on land but also has abnormally heavy bones and eyes placed high on skull, both of which are trademarks of aquatic or semi-aquatic hunters. Tooth chemistry studies tells us that Pakicetus was likely a freshwater hunter.
Unfortunately, a full individual skeleton of Pakicetus has never been found, leaving us to reconstruct this animal with bits and pieces. That said, fragments of many different individuals have been found, allowing us to construct a near full skeleton of the animal.
8 to 10 million years later, we find Dorudon atrox, a fully aquatic whale with tiny hind legs (modern whales no longer have hind legs), hands that form flippers (similar to modern whales), and tail bones that strongly suggest it sported a tail fluke similar to modern whales. It lived and hunted in saltwater. We have several extremely well preserved specimens of Dorudon (and its close relative, Basilosaurus) in the fossil record, making it a wonderful species to glean information about whale evolution.
In-between the two groups we find a rich fossil record of diverse whale-like species, unfortunately, most are known only from partial skulls.
It's largely assumed, because we don't yet have any earlier fossils than Pakicetus confirmed (though some are suspected), that a transition between these two forms (Pakicetus and Dorudon) happened in a relatively linear pathway during that 8 million year time span separating the two groups.
Several years back, Richard Sternberg made a speech that has become popular among the anti-evo community. In it, he claims that 8 million years isn't enough time for that transition to have taken place because there are too many changes that occur between the two groups. In his speech he lists 15 changes. Because Sternberg is a trained scientist and geneticist, I feel it's worth considering his claims.
Above is his speech for you to hear for yourself. Below, I have outlined the 15 changes he said must have happened during that 8 million year transition. I have fact checked them to see if they are indeed valid. I have rated each claim as either "True", "Partially True", "Invalid", or "False". These are my results:
Claim 1 - They would have had to evolve a countercurrent heat exchange system because testes moved from outside to inside the body
False: All mammals already have a well developed countercurrent heat exchange system which we use to cool off body-parts that are too warm, including... wait for it... our testes! When you blush while running, you are using this countercurrent heat exchange system too cool off internal organs. If you're a guy, you may have noticed a change in blood flow to your testicles as well after a run. Yep, that's the countercurrent heat exchange system doing its thing. To learn more about it, read this articles about bull testes: http://extension.missouri.edu/publications/DisplayPrinterFriendlyPub.aspx?P=G2016
Furthermore, even if this first claim wasn’t false, it would be invalid because we don’t know what pakecitid testes or basilosaurid testes were like. Testes didn’t fossilize in either group. It’s possible both had external testes but it's much more likely they both had internal testes. Why? Because hippos, the closest living relatives to whales, have internal testes and likely inherited them from a common ancestor with whales before Pakicetus. For more on hippo testes, here’s a fun read.
Claim 2 - They must have evolved ball vertebra because unlike a dog’s tail that wags side to side, whales need a tail that moves up and down
Partially true: Apparently Richard Sternberg he has never seen a dog up close before. They can move their tails up and down as well as left to right. Maybe he's talking about what are called ball vertebra at the end of the tail where the fluke is in Basilosaurids. These are small, rounded tail bones without projections, allowing for more flexibility of the fluke. Pakicetus is not known to have ball vertebra at the end of its tail.
This means there needed to be a reduction of projections in the tail bone. Reductions are pretty easy for evolution to do. Many dog breeds, for example, have reduced tail bone numbers.
Claim 3 - They need to have evolved tail flukes
True: Basilosaurids have clear signs of tail fluke attachment on the end of the tail, pakicetids do not. That said, while bones can’t tell us for sure, pakicetids may have had flattened tails like otters.
The transition from a land mammal tail to a fluked tail is not shown in the fossil record because flukes, being made mostly of cartilage, don’t often fossilize. That said, we can easily think of a gradual step by step process starting with a widening of the tail, then a gradual migration of that widening to the end of the tail. For real modern examples of several possible steps in this transition, see an otter tail, then a beaver tail, than a manatee, then a dugong. Could this have been a the way flukes evolved? With the data currently available, we cannot yet be certain.
Claim 4 - They had to evolve new musculature for the tail fluke
False: Tail flukes don't have muscles, they are cartilage structures. Muscles of a whale tail are larger than those found in most mammal tails but they appear to be the same muscle systems (the epaxial mass and hypaxial mass) that normal mammal tails have. http://www.whalesforever.com/whales-fins-and-flukes.html
Claim 5 - They need need to have reorganization of the kidneys to drink salt water
Partially true: Tooth chemistry in pakicetids strongly suggests they were mostly freshwater animals and basilosaurids were mostly salt water animals. That said, kidney changes between freshwater mammals and saltwater mammals are small. No need to reorganization. The only change needed is the elongation of internal structures called “loops of Henle”. Here’s a video on the loop of henle: https://www.youtube.com/watch?v=cYyJF_aSC6o
The loop of henle varies in length from individual to individual which is one of many reasons we vary in how much salt and alcohol we can safely consume. Natural selection simply need promote one length over the other to adjust a species to a new environment.
Here’s an article about the anatomical difference between saltwater mammal kidneys and freshwater mammal kidneys: http://www.scientificamerican.com/article/how-can-sea-mammals-drink/
Interestingly, according to tooth chemistry analysis, Ambulocetus—a species representing a transitional branch between pakicetids and basilosaurids—lived in brackish water. This is the perfect way to transition from a freshwater to a saltwater environment.
Claim 6 - They have to evolve the ability to nurse underwater
Invalid: Yes, whales nurse underwater but so can hippos, their closest living relatives (they also nurse on land sometimes). This means the trait likely arose before the lineages split and that pakicetus was already nursing underwater. The claim is completely irrelevant to the 8 million year gap between pakicetids and basilosaurids. Here’s an article about hippos nursing both on land and underwater. http://blogs.sandiegozoo.org/2011/02/02/baby-hippo/
Claim 7 - The nipples had to be modified for underwater nursing
False: From the mother's perspective, nursing works exactly the same in the water as it does on land. In whales, as is the case for most mammals with long snouts, the calf sticks out and curls it's tongue around the nipple, creating a straw for them to drink through. As mentioned, hippos nurse on land and underwater with no problems.
In modern whales, nipples are tucked under flaps of fat in the skin but that’s for the mother to swim without drag, not to aid in suckling. We don’t know if the fat flaps were present in pakicetids or basilosaurids so even that fat flap is invalid to Sternberg's argument.
In modern whales, nipples are tucked under flaps of fat in the skin but that’s for the mother to swim without drag, not to aid in suckling. We don’t know if the fat flaps were present in pakicetids or basilosaurids so even that fat flap is invalid to Sternberg's argument.
Claim 8 Orientation of fetus has to change
Invalid: This claim is invalid because we don't know how pakicetid or basilosaurid babies were carried in the womb.
I assume he basses this claim on a specimen of Maiacetus (a genus of whale between pakicetids and basilosaurids) that has a fetus in it's abdomen with it's face pointing toward the mothers hind quarters. This suggest it would have been born head-first. This is in contrast to most modern whales that give birth tail first. That said, the orientation of the fetus in Maiacetus may not have been how it would have been during birth since fetuses often switch orientation multiple times during pregnancy. Furthermore, hippos (the whale's closet living relatives) usually give birth hind-first just like whales, and often give birth in the water. This means the adaptation of hind-first birth in whales may well have occurred before pakicetus. Here’s a film of a hippo giving birth in the water: https://youtu.be/pGxi-ZNMsaU
I assume he basses this claim on a specimen of Maiacetus (a genus of whale between pakicetids and basilosaurids) that has a fetus in it's abdomen with it's face pointing toward the mothers hind quarters. This suggest it would have been born head-first. This is in contrast to most modern whales that give birth tail first. That said, the orientation of the fetus in Maiacetus may not have been how it would have been during birth since fetuses often switch orientation multiple times during pregnancy. Furthermore, hippos (the whale's closet living relatives) usually give birth hind-first just like whales, and often give birth in the water. This means the adaptation of hind-first birth in whales may well have occurred before pakicetus. Here’s a film of a hippo giving birth in the water: https://youtu.be/pGxi-ZNMsaU
Here’s film of a hippo giving birth on land showing they have babies hind-first: https://www.youtube.com/watch?v=oLieIaWWDbQ
Claim 9 - The hind limbs must be reduced
True: Pakicetids have long hind legs, basilosaurids have super short hind legs. This is the biggest change that we know occurred between the two groups of whales.
Claim 10 - Forelimbs transform into flippers
True: That said, this is not a difficult transition for evolution to make. In fetuses, the hands of all mammals start out as flippers, then, between the finger bones, a process called apoptosis (cell death) begins to “cut” the space between fingers. To give webbed or flippered hands, this process can start late, end early, or not occur at all. Many different types of mutations can cause apoptosis to slow down, speed up, or fail, resulting in flippers or webbed hands. https://en.wikipedia.org/wiki/Apoptosis.
Claim 11 - They needed to evolve new hydrodynamic properties of the skin
Invalid: It is true that a modern whale's skin is way better than ours at resisting degradation in water, that said, whales didn't evolve from humans, they evolved from artiodactyls. Modern artiodactyls (such as hippos) have wonderfully waterproof skin. This adaptation was likely already present in pakicetids. As mentioned, many features of pakicetid skeletons suggest they were living a largely aquatic lifestyle. Here's an article about their aquatic features: http://link.springer.com/article/10.1007/s12052-009-0135-2
Claim 12 - They need special lungs
Invalid: we don’t know what pakicetid lungs or basilosaurid lungs were like so this issue is not actually relevant to his argument. Modern whales lungs aren’t much different from normal mammal lungs but they are more efficient. These efficiencies might have evolved before pakicetids, between pakicetids and basilosaurids, or after basilosaurids but before modern whales. There is no way to tell from the fossil record.
Claim 13 - Whales had to evolve novel muscle systems for the blowhole
False: First off, mammals already have muscles to power their nostrils, even humans (though ours are super small). Here’s video of hippos using their nostril muscles in a way almost identical to how baleen whales use theirs: https://www.youtube.com/watch?v=86ZHdF9hmig
Toothed whales (dolphins and the like) seem, at fist glance, to have novel muscles in the melon and blowhole but it has not been confirmed that these muscles are actual new. Instead, while more studies need to be done to know for sure, it appears that in toothed whales, the muscles of the lips have migrated up into the head for use around the melon and inside the blowhole. This appears to be the case when we watch the face structures develop in dolphin fetuses and when we note the lack of lip muscles in modern toothed whales. Notice how these dolphins no longer have movable lips like hippos and other mammals: https://www.youtube.com/watch?v=KMZ7oOCXfP8
Furthermore we don't know what the muscles in pakicetid nostils or basilosaurid nostrils were like, making Sternberg's claim invalid on-top of being false.
Furthermore we don't know what the muscles in pakicetid nostils or basilosaurid nostrils were like, making Sternberg's claim invalid on-top of being false.
Claim 14 - The eyes must be modified
Invalid: Again, we don’t know what pakicetid eyes were like nor do we know what basilosaurid eyes were like. We have no way of knowing if any significant changes occurred in eyes between the two groups.
Claim 15 - Modification of the teeth had to occur
True but not significant: The teeth of pakicetids and basilosaurids are similar but basilosaurids are simpler (missing one cusp on the molars) and rougher (have a jagged top). Teeth can be compared in skulls here: http://link.springer.com/article/10.1007/s12052-009-0135-2
CONCLUSION
Only 4 out of 15 of Sternberg's "facts" were actually true. His conclusion that there was not enough time for whales to evolve is not verified by the data he puts forth.
