Lifeboat Foundation

Part 1: 10,000 years      Part 2: 100,000 years       Part 3: a million years

A million years. A hundred thousand years ago people looked like — and were — people. But go back a million years and things were different. For one thing, the modern lack of other species very similar to us (i.e. also in the genus Homo) did not hold. There were others, very similar in many ways, yet different as well. Not only Homo floresiensis (the “hobbits”), but also Homo antecessor and Homo heidelbergensis. Antecessor lived up to about 800,000 years ago and was roughly the height of modern humans, though of more robust build. Bones showing damage from stone tools suggest that antecessor both practiced cannabalism, and used tools, sometimes at the same time.

Their brain size was about 20% below ours, which still counts as large and, apparently, intelligent. With a low forehead and not much chin, they are only known to have lived in Europe. Homo heidelbergensis lived more recently than antecessor and may in fact be evolved from antecessor, just as we will evolve into something different if we survive long enough. They lived more recently than antecessor and may in fact be evolved from antecessor, just as we will evolve into something different if we survive long enough. First discovered in the form of a jaw found near Heidelberg in 1907, Heidelbergensis stood tall, about 6 feet in Europe and often exceeding 7 in South Africa, and was muscular and strong. The European population of heidelbergensis is likely to have evolved into the Neanderthals. The African population may have evolved into modern humans, which would make heidelbergensis our common ancestor. Compared to heidelbergensis, however, we have higher foreheads and flatter faces, and are smaller boned. (Technically speaking, heidelbergensis was “robust” while we are “gracile.”) In this we are not unlike a heidelbergensis child, illustrating our neoteny — the slowing of development, tending to lead to the retention of childhood characteristics into adulthood. Neoteny is considered a broad characteristic of modern humans compared to our ancestors. It helps explain our relatively long trunks, short limbs, small brow ridges, small noses, high foreheads, and flat faces. This trend may continue into the future. Neoteny is also a broad characteristic of dogs, which are neotenized wolves.

To further illustrate the amount of evolutionary change that can occur in a million years, consider the modern primates most closely related to humans, chimpanzees (Pan Troglodyte) and bonobos (Pan paniscus). These species split from their own common ancestor roughly a million years ago. The bonobo is smaller than the chimpanzee, but behavioral differences are dramatic. Far less aggressive than the chimp, the bonobo is known for its unique sexual life. Bonobo sex, both hetero– and homo-, has an important place in the everyday function of bonobo society, for example in smoothing over conflicts to avoid fighting. This seems to be absent in the larger, more aggressive and dangerous chimpanzee. Additionally, bonobo society is mostly matriarchal (female dominated) while chimpanzees are highly patriarchal (male dominated), with a dominance heirarchy in a troop placing essentially all adult females below all adult males. Given such huge behavioral differences, it is likely that Homo heidelbergensis temperament, behavior, and society differed considerably from our own (and from traditional human tribal societies, which also tend to differ greatly from each other). Behavioral differences likely exceeded the not inconsiderable differences in appearance and physique. We will never know this for sure, of course, but we can make some guesses about them. The general developmental principle that humans are neotenized relative to their predecessors most likely influences our emotional development as well, resulting in human adults having some temperamental characteristics more typical of heidelbergensis youths than heidelbergensis adults. If one has trouble believing that neotenized physical characteristics have much to recommend themselves for physically dealing with the world — running around, finding food — as I do, then one must suspect that it is the neural and temperamental characteristics provided by neoteny that drove the neotenization of our species, with our also-neotenized physical characteristics being an accidental side effect. So what might those neotenous brain and mind-related traits be?

One trait relates to the fact that retaining juvenile characteristics tends to delay adulthood. This means a longer childhood, which today’s developed nations use for extended schooling. A lengthened childhood period helps here, as you can’t teach an old dog new tricks (so the saying goes). In fact, human childhood is so long that most other animals die of old age in the time humans take just to grow up. By extending youth, humans likely have a longer period of high neural plasticity, supporting improved ability to learn over a longer period of time. Still, like old dogs, old humans in some ways learn less quickly. In the future, if neoteny proceeds further, that may change.

Dogs can serve as more than a source of sayings. They also provide a great example of neoteny themselves. Dogs are a neotenized form of the gray wolf, domesticated at least 15,000 years ago. Since that time, they have held on to their position as “man’s best friend” in large part because of neotenized aspects of their temperaments. Why? Remember that a standard gray wolf is *not* man’s best friend. A gray wolves would *eat* a man (woman, and especially child) if it figured it could get away with it. Gray wolves (fighting weight may exceed 120 pounds) are definitely not good with small kids, like so many dogs are. Wolf puppies, however, are cute, fluffy, playful and fun, like many adult dogs. (In fact, so are the fiercest lion and grizzly bear cubs.) Thus neotenized mammal adults like us may be expected to be comparatively friendly, sociable and playful. And cute: we appear genetically predispositioned to find juvenile characteristics like short arms, roundish, flattish faces with short or no muzzle, and small noses endearing. Can you think of any politicians that one might suspect benefit in popularity from possessing neotenously cherubic or “cute” physical features? Many other animals are analogously programmed. This helps the young to benefit from, rather than be forced to compete with, the superior experience, skill and strength of parents and other adults.

The amounts and types of evolutionary differences between us and H. heidelbergensis suggest the amount and types of evolutionary change we may undergo in our next several hundred thousand years. Thus our brains may enlarge, perhaps by around 20%. Will that make every man an Einstein, every woman a Curie? Perhaps (and perhaps much more than that). Einstein’s brain was on the small side, but surely an extra 20% would be good for something. Considering bodies, with heidelbergensis’s robust physique and our gracile one, if this trend continues basketball has good long-term future prospects, while sumo wrestling may eventually face some challenges. No need to panic though — at a time scale of hundreds of thousands of years there is plenty of time for sports franchises to adapt to changing times. Moving to neoteny, a continuation of the trend toward increased neoteny suggests a distant future of shorter limbs and longer trunks, baby-faced adults, and more playful, friendly cultures. Hopefully, increased neoteny, by in a sense lengthening youth, will result in longer natural life spans, since getting old is not exactly a sign of youth.

Chimpanzees and bonobos, our closest living relatives, split from their most recent common ancestor about a million years ago and thus their differences form an interesting animal analogy to the amount of change we might expect in ourselves at that time scale. They look quite different and act even more differently, with chimp society patriarchal and bonobos matriarchal. While chimps are promiscuous in a sense any human can understand, bonobos raise to a whole new level the integration of sex into multiple facets of daily life. Bonobo philosophy seems to emphasize the “make love not war” concept far more than humans. There may possibly be human swingers and adult industry careerists who could empathize with bonobo society to a degree, but to most of us it’s pretty alien. In a million years our descendants may be similarly alien to present day human understanding, but the only way to tell for sure is to wait and see. Since no one except a few die-hard singularitarians expect to be able to wait that long, the curious will simply need to use their imaginations, so imagine away if you like and bon voyage.

Notes

“Bones showing damage from stone tools suggest that antecessor practiced cannabalism, aided by tools.” Y. Fernández-Jalvo, J. Carlos Díez, I. Cáceres and J. Rosell, Human cannibalism in the Early Pleistocene of Europe (Gran Dolina, Sierra de Atapuerca, Burgos, Spain), Journal of Human Evolution, Sept.-Oct. 1999, vol. 37, no. 3 – 4, pp. 591 – 622. http://www.sciencedirect.com/science/article/pii/S004724849990324X.