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To read the fossil record literally is to discover the inexplicably as all other primates appear. Again, Science egitimacy of punctuated equilibrium (discussed in Part One) insists they evolved from monkeys, but the evidence to support as a plausible explanation. "Punk eek", as detractors call it, that claim is as specious as the prosimian—monkey link. The points out that in the fossil record life-forms do seem simply to _ transitional bones needed to support it are simply nor in the appear on Earth, most often after extinction events but not fossil record. always. Both the supposed proto-primates and flowering If this isn't a distinct pattern of punctuated equilibrium, then plants appear during the period preceding the Cretaceous what is? extinction. They come when they come, so the relatively sudden post-extinction appearance of the earliest primates, the | THE PUZZLING MIOCENE prosimians (lemurs, lorises, tarsiers), is one of many sudden In terms of primate evolution, the Miocene makes little manifestations. sense. By 25 million years ago, when it begins, prosimians In terms of human origins, it begs this question: did proto- have been around for about 30 million years and monkeys for primates actually evolve into prosimians, into monkeys, into 10 million years. Yet in the Miocene's ample fossil record, apes, into humans? Or did prosimians appear, monkeys prosimians and monkeys are rare, while the new arrivals, the appear, apes appear, and humans appear? Or, in our "special" apes, are all over the place. case, were we created? The Miocene epoch stretches from 25 million to 5.0 million However it happened, there is a pattern. The earliest years ago. (These are approximations quoted differently in prosimians are found in the fossil record after the various sources; I round off to the easiest numbers to keep Mesozoic/Cenozoic boundary at 65 million years ago. It is track of.) During those 20 million years, the apes flourish. assumed their ancestors will someday be found as one of | They produce two-dozen different genera (types), and many countless "missing links" needed to make an airtight case for have more than one species within the genus. Those apes Darwinian evolution. Prosimians dominate through the come in the same range of sizes they exhibit today, from Palaeocene and the Eocene, lasting from 65 to 35 million years smallish gibbon-like creatures, to mid-range chimp-sized ones, ago. (There won't be a test on terms or dates, so don't worry to large gorilla-sized ones, to super-sized Gigantopithecus, about memorising them; just try to known only by many teeth and a keep the time-flow in mind.) At few mandibles (jawbones) from 35 million years ago, the India and China. Oligocene epoch begins and the That's another interesting thing first monkeys come with it. . about Miocene apes: their fossils Again, Science assumes that Science assumes that monkeys are found literally everywhere in the monkeys evolved from prosimians, AH Old World—Africa, Europe, Asia. even though evidence of that tran- evolved from prosimians, Most of them are known by the sition is nowhere in sight. In fact, even though evidence of that durable teeth and jaws that define transition is nowhere in sight. there is strong evidence pointing in the other direction, toward the dreaded stasis of punctuated equi- librium. The lemurs, lorises and tarsiers of today are essentially just Gigantopithecus, while many others supply enough post-cranial (below the head) bones to grant a reason- ably clear image of them. They pre- sent an interesting mix of anatomi- as they were 50 million years ago. cal features. Actually, "confusing" Some species have gone extinct is more like it. They are clearly dif- while others have modified into new forms, but lemurs and ferent from monkeys in that they have no tails, just like mod- lorises still have wet noses and tarsiers still have dry, which ern apes. However, their arms tend to be more like monkey seems always to have been the case. That's why tarsiers are arms—the same length as their legs. Modern ape arms are sig- assumed to be responsible for spinning off monkeys and all the nificantly longer than their legs so they can "walk" comfort- rest. ably on their front knuckles. More than any other reason, this Monkeys start appearing at 35 million years ago, looking is why we hear so little from anthropologists about Miocene vastly different from prosimians. There are certain physiologi- apes. Their arms don't make sense as the forelimbs of an cal links, to be sure, such as grasping hands and feet to permit ancestral quadruped. Miocene arms fit better with...some- easy movement through trees. However, prosimians cling and thing else. jump to move around, while monkeys favour brachiating— This is not to say, of course, that no ape arms in the Miocene swinging along by their arms. Also, prosimians live far more fossil record are longer than legs. That's nowhere near to by their sense of smell than do monkeys. This list goes on. being determined because many _ species—like The reason they're linked in an evolutionary flowchart is Gigantopithecus—have yet to provide their arm bones. because they seem close enough in enough ways to make the However, since we do have some tailless, ape-like bodies with linkage stick. Simple as that. Science focuses on the monkey-like arms and hands, we have to consider how such a similarities and tries hard to ignore their gaping discrepancies, hybrid would move around. Swing through trees by its arms, assuming—as always—that there is plenty of time for like a monkey? Not likely. Monkey arms are designed to evolution to do its magic and generate those inexplicable carry a monkey's slight body. An ape's body needs to be differences. brachiated and leveraged by an ape's much longer, stouter, For the next 10 million years the larger, stronger, more stronger arms. So how about...walking? "advanced" monkeys compete with prosimians for arboreal From a physiological standpoint, an ape-like body with resources, quickly gaining the upper hand over their monkey-like arms and hands does not move as easily or com- "ancestors" and driving several of them to extinction. fortably as a quadruped (down on all fours). It simply can't Then, at around 25 million years ago, the Miocene epoch happen. In fact, there's really only one posture that lends itself brings the first apes into the fossil record, as suddenly and to the carriage of such a monkey-ape hybrid, and that's inexplicably as all other primates appear. Again, Science insists they evolved from monkeys, but the evidence to support that claim is as specious as the prosimian—monkey link. The transitional bones needed to support it are simply nof in the fossil record. If this isn't a distinct pattern of punctuated equilibrium, then what is? evolved from prosimians, : even though evidence of that transition is nowhere in sight. rest. Monkeys start appearing at 35 million years ago, looking vastly different from prosimians. There are certain physiologi- cal links, to be sure, such as grasping hands and feet to permit easy movement through trees. However, prosimians cling and jump to move around, while monkeys favour brachiating— swinging along by their arms. Also, prosimians live far more by their sense of smell than do monkeys. This list goes on. The reason they're linked in an evolutionary flowchart is because they seem close enough in enough ways to make the linkage stick. Simple as that. Science focuses on the similarities and tries hard to ignore their gaping discrepancies, assuming—as always—that there is plenty of time for evolution to do its magic and generate those inexplicable differences. For the next 10 million years the larger, stronger, more "advanced" monkeys compete with prosimians for arboreal resources, quickly gaining the upper hand over their "ancestors" and driving several of them to extinction. Then, at around 25 million years ago, the Miocene epoch brings the first apes into the fossil record, as suddenly and 48 = NEXUS Science assumes that monkeys www.nexusmagazine.com FEBRUARY — MARCH 2003