Eugene M. McCarthy

When confronted with stories in the Daily Nimbyist Bungaloid Curtain-Twitcher I murmur words such as 'this', 'touch', 'with', 'don't' and 'bargepole'. However, when alerted to the following gem by my correspondent B. C. of Swindon, I really had to investigate. The headline is enough to make one gasp and stretch one's eyes:
 * 'Humans evolved after a female chimpanzee mated with a pig': Extraordinary claim made by American geneticist

Eugene M. McCarthy earned a B.S. in mathematics, and an M.S. and Ph.D. in genetics, all from the University of Georgia. His Master's thesis was on recombinational speciation, and Ph.D. thesis was on computational genomics.

McCarthy likes to wave his credentials in genetics and hybridization around when arguing with other scientists, even when the other scientists' own expertise is completely relevant, e.g.:
 * "Please note that Dr. Prothero is neither trained as a geneticist, nor is he an expert on hybridization." is a paleontologist and geologist.
 * "First, please note that PZ Myers is neither trained as a geneticist, nor is he an expert on hybridization. I myself have a masters and Ph.D. in genetics from one of the leading genetics departments in the country (the University of Georgia's) and I've spent a lifetime investigating hybridization." Myers is an evolutionary developmental biologist.

Avian hybrids
Since his doctorate work, McCarthy has focused on hybridization, publishing the book Handbook of Avian Hybrids of the World with Oxford University Press. The Handbook has received some enthusiastically positive academic reviews. One reviewer, Gary R. Graves, who is the Curator of Birds at the Smithsonian Institution, praised the comprehensiveness of the book but also had some serious criticisms of it. Graves' praise for the book's comprehensiveness is tempered by the book's lack of discrimination, "… those who cast a wide net had better be prepared to throw back the by-catch. Unfortunately, McCarthy kept it all—the good, the bad, and the vague." Graves describes some types of damage caused by this lack of discrimination:
 * Introduction of "unsupported records in the the literature that are maddeningly difficult to eradicate once published."
 * "…less savvy users may naturally assume the documentation backing the hybrid records in the book meets some quality threshold."
 * "Inclusion of hybrids based on sight records and photographs of free-living birds endorses the notion promoted in many birding publications that accurate diagnosis of hybrids observed in the field is not only possible but probable."
 * "The most serious problem with compilations of this nature is that synthesists may be tempted to use the data for phylogenetic or macroecological studies of hybridization."

Stabilization Theory
In 2008, McCarthy wrote a manuscript describing his idea of "Stabilization Theory". The manuscript was submitted to Oxford University Press but rejected for publication because it did not have a consensus for publication from peer reviews. The theory has been described by PZ Myers as being similar to Saltationism, which is a type of non-Darwinian evolution. All of the theories of non-Darwinian evolution have been rejected as being unsupported by evidence since the time of the Modern Synthesis of evolution (1936-1947). Indeed, McCarthy rejects the modern Synthesis, specifically rejecting natural selection as being the primary driver of evolution, and rejecting microevolution as being responsible for macroevolution. Instead, McCarthy literally turns the tree of life upside-down, and argues that hybridization between species is the primary driver of evolution, resulting in his Stabilization Theory. McCarthy also rejects the concepts of convergent evolution and adaptive radiation.

After claiming that armadillos may have descended from ankylosaurs, basically because they look similar, McCarthy continued with another of other examples. Bats are descendants of pterosaurs. Whales came from mosasaurs. Seals are the children of plesiosaurs. Dinosaurs weren’t actually giant reptiles, they were big mammals. These ideas are contrary to all of the evidence, of course, but one thing you’ll learn from this book is that the evidence doesn’t have to be considered. It’s all about McCarthy’s belief in the fixity of species — species don’t change at all, ever, and all evolutionary novelty comes from the sudden production of new species by ‘stabilization processes’, like hybridization.

The theory has had some interest from a creationist and an intelligent design proponent, but only because the theory is in opposition to the Modern Synthesis of evolution.

Human origins
We believe that humans are related to chimpanzees because humans share so many traits with chimpanzees. Is it not rational then also, if pigs have all the traits that distinguish humans from other primates, to suppose that humans are also related to pigs? Let us take it as our hypothesis, then, that humans are the product of ancient hybridization between pig and chimpanzee. McCarthy published a treatise on human origins, entitled The Hybrid Hypothesis: A new theory of human origins, that considers the possibility that human beings might have a chimpanzee-pig hybrid in their ancestry. (PZ Myers has termed this the "Monkey-Fucked-A-Pig (MFAP) hypothesis". )

McCarthy's hypothesis is based primarily on his research on bird hybrids, specifically that bird hybrids are partially-fertile about 8-times more often than they are completely sterile. Such partially-fertile offspring can produce offpring from backcrossing with one of the original two species. McCarthy however admits that: Though there are other ways of detecting them, with nucleotide sequence data, it can be very difficult to identify later-generation backcross hybrids derived from several repeated generations of backcrossing (and this would be especially true of any remote descendants of backcross hybrids produced in ancient times, which is what I'm proposing humans may actually be).

This is the crux of the problem with this hypothesis. McCarthy has made an extraordinary hypothesis, but extraordinary claims require extraordinary evidence, and McCarthy admits that there is no way to verify his hypothesis with genetic evidence.

A further problem with McCarthy's hypothesis is that the documentation of successful crosses would seem to be either within biological orders, or based on unreliable unscientific reports. This extends rather than fixes the problems noted by Graves in McCarthy's avian hybrids book, above. The unscientific reports are typically from newspapers, from before the era of genetic testing (basically protoscience), or from photographic evidence of what could easily be explained as birth defects. Examples are: • 2

McCarthy does list on his website some speculative cross-order "hybrids" but he does not stand behind them as documented fact, e.g. the "cabbit", an alleged cross between a cat (Felix domesticus, order Carnivora) and a rabbit (family Leporidae, order Lagomorpha). The photographic evidence of cabbits appears to be just a cat with a stubby tail and a birth defect in its forelegs.

Hybridization between chimp and pig, though, is a much bigger stretch. It requires interbreeding between separate orders of mammal. Chimps are primates, and pigs are artiodactyls (even-toed ungulates). Despite McCarthy's suggestions to the contrary, reports of hybrids between different orders of mammal, though, are, literally, incredible. His suggestion that the platypus is the result of hybridization between mammals and birds – an even bigger ask – seems to rest on a misunderstanding of the inheritance of chromosomes. Although some of the genetics of platypuses seems birdlike, this is much more consistent with its primitive state, and a mark of a shared inheritance between birds and reptiles (preserved in primitive mammals) than direct evidence for miscegenation.

Because McCarthy is unable to use the genome to support his hypothesis, he instead points to morphological similarities to make his case. Nearly all biologist bloggers have rejected this. This theory has been cited uncritically by both InfoWars and YourNewsWire.

While there might be morphological similarities, nearly all other evolutionary biologists have long ago come to the conclusion that this does not necessarily imply a relational connection between two species (e.g., see convergent evolution).

McCarthy considers in detail the hypothesis that echidnas and platypuses are derived from hybrid crosses between birds and mammals. His website also features a large catalog of other cases he proposes might be similarly clade-defying hybrids, among them a list of possible human-goat hybrids.

The media
McCarthy's theories have appealed to various media (Daily Mail, The Times of India, Infowars ) because of its sensationalism. These media do not necessarily agree with McCarthy, but McCarthy's sloppiness (lack of evidence, refusal to cull out bad data, and extraordinary claims) enables this circus. I believe that the Daily Mail, Alex Jones et al. are very invested in making him out to be a mainstream academic, and using that framing to undermine science in the furthering of their own agendas. It’s a very insidious tactic.