* Creeps or jerks was a joke formulated by the great biologists Stephen Jay Gould and John Turner, concerning the arguments about whether evolution proceeded continuously or with catastrophic game-changing disruption. These two ideas, more formally known as phyletic gradualism and punctuated equilibrium, competed for years. The answer, as so often is the case in science, is, broadly, a bit of both.
* Though he wrote in the margin of one of his notebooks “never say higher or lower,” more as an expression of caution for the idea of evolutionary progress. He noted that some barnacles become simpler in chronological evolution. Darwin did love a barnacle.
* The ranks genus and species are the last, and thus most specific of the hierarchies of classification, or taxonomy. The standard ranking is Kingdom, Phylum, Class, Order, Family, Genus, Species. I was taught this with the memorable if not kind mnemonic, “kings play cards on fat girls’ stomachs,” though there are plenty of other versions. “King Philip came over for group sex” may suit your fancies better.
* There is officially a category below species—subspecies—in which different types within a species can be separated. Gorilla is the genus, and there are species within that genus: Gorilla beringei, informally named the eastern gorilla, has the dubious honor of being named after Friedrich Robert von Beringe, the first person to shoot one. The western gorilla, Gorilla gorilla is the most abundant species. But there are also two subspecies of these, one of which is the western lowland gorilla; Gorilla gorilla gorilla is its scientific name. It is OK to find this amusing, though taxonomists are deadly serious people.
Most scientists refer to us as “anatomically modern humans.” Earlier versions of Homo sapiens have been found and documented, the oldest of which, as of June 2017, are the Jebel Irhoud specimens from Morocco, dated to around 300,000 years ago. As an attempt to distinguish between archaic Homo sapiens and us, as well as other proposed incarnations, some scientists use the subspecies classification Homo sapiens sapiens to denote modern humans.
* Zebra with any other equine animal; male lion with a lady tiger; jack donkey with a female horse; jenny donkey with a male horse; polar bear with a grizzly—rare but presumably utterly terrifying.
* There have been dozens more proposed, some more plausible than others, from scientists, sociologists, novelists, and fabulists.
* A brief word about cryptids—proposed, mythological, or vaguely reported species that remain elusive, theoretical, or alien to science. For centuries there have been myths and legends about extant humanlike contemporaries of ours, ape men, yetis in the Himalayas, Sasquatch in Canada, Barmanou in Southeast Asia, Manananggal of the Philippines, the Australian yowie, and Big Foot and many, many others in the rural United States. None of these has ever come close to verification in a way that would slake a scientist’s thirst, including such things as evidence of bodies, fossils, hunting or feeding behavior, or even a decent photo, which you might find surprising in a world with literally billions of cameras and now camera phones, and an industry dedicated to finding these elusive monkey-men. When DNA began to become a useful tool in the identification and classification of animals in the 1990s, some studies emerged, and continue to do so to this day, that claim to prove the existence of one of these cryptid ape-men. So far, all of them have been rejected outright by scientists, with a mixture of derision and, in recent high-profile media-courting claims in the UK, weariness. There is the legend of an ape-man on the island of Flores called Ebu Gogo, short and hairy, the females with long pendulous breasts. It is tempting to link the very real remains of the long-extinct Homo floresiensis with these legends. But it is far more likely that Ebu Gogo is simply a local version of the myth of orang pendek, a short-statured cryptid story that is common around Sumatra and other islands. Cryptozoology lumbers onward, on the fringes of science and value.
† In the final stages of writing this book, two new studies yet again upturned the Flores story. In April 2016, Thomas Sutikna’s paper significantly revised the dates of Homo floresiensis. Cave systems are often dynamic geological locations with uneven stratigraphy. Liang Bua is no different, and the most recent date for the Hobbits’ occupation of the cave system was amended to be more like 50,000 years ago. In June 2016, a fragment of jaw and some teeth from a family of different, even smaller, Hobbits were found 30 miles east, this time 700,000 years old. They have not yet been named, but there’s no doubt much more is to come.
* The first, in 1958, was for determining the amino acid sequence of the insulin protein. He is the only person to have won the chemistry gong twice, and one of only four to have won two Nobels in any category. Fred Sanger died during the writing of this book, but he will be well remembered in his techniques, and in the Wellcome Trust Sanger Institute outside Cambridge, close to where he lived; it is one of the great centers of genome research in the world.
* This process occurs in utero. The egg that made you was made inside your mother’s ovaries while she was inside her mother. Your DNA was forged inside your grandmother.
* Bones discovered in La Chapelle-aux-Saints in 1908 were the ones that gave rise to the stereotype of a hunched caveman oaf. In the 1980s, much more forensic analysis by Eric Trinkaus showed that this was a forty-year-old man hunched because of osteoarthritis, not because that’s how they all stood.
* Actually they were almost all Cretaceous animals in that film. But Cretaceous Park is probably trickier to pronounce.
* There are many types of mutation in DNA that cause problems or evolution. All alter the production of the protein that is encoded by that stretch of DNA. Some delete single letters: Genome becomes Gnome. Some add a period before the sentence is finishe. A missense mutation, as seen in the KE family, introduces ectopic punctuation, so the protein becomes mangled: “too late” becomes “tool ate.” If these mutations do not cause serious problems or death, then they can be the source of variation, which is the fuel for evolution.
† This phenomenon, where a single gene becomes known as the single cause of any characteristic, is interrogated in Chapter 5.
* The keen-eyed might have noticed that there are three versions of FOXP2 written on this page. This is because, rather vexingly, geneticists use different versions of capitalization in different species: FOXP2 is human, Foxp2 is mouse, FoxP2 is zebra finch. I have no idea why.
* To the Italian tourist who vomited after I asked her to smell a tube of androstenone for a BBC television series in 2010 in Covent Garden Flower Market in London, I apologize.
* More on red hair and MC1R in Chapter 2.
* I wish to acknowledge Lara Cassidy, a researcher at Trinity College Dublin. I hadn’t thought about Neanderthals and the problems of species definitions very hard until she challenged me in a public lecture. She was right and I was wrong, and it made me think, so I thank her for that.
* The genetics of the dead is a science moving at exhilarating speed, and reports of bones replete with new sources of DNA are being published on a weekly basis. But in April 2017, Viviane Slon, Svante Pääbo, and a Spanish team managed to do something almost magical. They had been to seven caves known to have once been homes to Neanderthals and Denisovans. They took sediment samples and succeeded in extracting wisps of mitochondrial DNA directly from the dirt. There in the cave floors, they found ghostly traces of the genes of woolly rhinos, cave bears, mammoths, and humans. We can now find the DNA of ancient people in places where bones no longer linger, and the door to past lives creaks open even further.