Ian Tattersall       . . .paleoanthropologist. Dr. Tattersall is the Director of and Curator in the Department of Anthropology at the famed American Museum of Natural History in New York City. He reports on fieldwork he has done around the world in hundreds of scholarly and popular articles (such as "We Were Not Alone" in Scientific American) and a dozen books including Becoming Human, The Last Neanderthal and Extinct Humans.

4:18

This is the first time in 5 million years that only one human species lives on earth, according to Dr. Ian Tattersall. Our zoological family (hominids) stretches back 5 million years, but our family ãtreeä is more accurately described as a bush. And for most of hominid history, multiple human species to lived on earth -- simultaneously. We were not alone.

Why does this all sound so strange? We're accustomed to things as they are, says Dr. Tattersall. And Aristotle misled us with the idea of a "great chain of being" that was destined to end up with us. To the contrary, says Dr. Tattersall. Our very remote hominid ancestors were very, very different from what we are today but it wasnât a straight shot from them to us. We are part of nature, not separate from it, and susceptible to the same kind of triage which determined the outcomes of all the other hominids.

Consider the Neanderthals, Dr. Tattersall's specialty. He's certain they were a separate species with an evolutionary history distinct from ours. No genes mixed, he asserts. Neanderthals lived very successfully (and notably differently from our predecessors) in Europe and Western Asia for 200,000 years. Modern humans turn up about 40,000 years ago, disrupt the tranquility, then suddenly, Neanderthals are gone. Dr. Tattersall sees a connection between these two facts.

Dr. Tattersall and his colleagues are learning how we became who we are anatomically by studying the fossil record. The archaeological record lends understanding to when and how our behavior became modern. It's nature at work, Dr. Tattersall reports. Innovation has been relatively rare and episodic in human evolution. How did we get to be large brained, small-faced, striding upright bipeds, with a very complex set of behavior patterns and our own peculiar human consciousness? Dramatically. Up until agriculture, the archaeological record -- incomplete as it is -- shows only four major technological steps. Each embodied some kind of a cognitive leap.

While Dr. Tattersall has spent a lifetime focused on the technical preoccupation of studying fossilized human remains, he is never far from their mystery and magic. He calls them icons. But what really fascinates him -- and most of us -- is how we came to be who we are, how we acquired consciousness approximately 50,000 years ago. He sees exaptation (in contrast to adaptation) at work. As in any species, our anatomy had to be ready before new behaviors were possible.

Before language, homo sapiens had to have appropriate upper respiratory tracts and brains capable of producing speech's underlying symbolism. What the evidence shows is that until about 40 to 60,000 years ago, anatomically modern humansâ behavior was fairly straightforward and fairly simple. The complexities came suddenly and during that 20,000 year period. Dr. Tattersall thinks we can be fairly confident that's when human consciousness as we know it today became established.

What happened? Dr. Tattersall's among those who answer: language. Language is not necessary to be human, he reminds us -- Neanderthals did just fine using very sophisticated, intuitive, non-language-dependent processes. That is, they were fine until symbolically reasoning humans showed up. Now you know why Dr. Tattersall describes homo sapiens as "dangerous."

[This Program was recorded January 22, 2001, in New York City, US.]

Conversation 1

Ian Tattersall explains for Paula Gordon and Bill Russell the difference between what it means to be human and -- where the problems arise -- when humans became humans. Dr. Tattersall describes as false the perspective created by the classic concept of the ãgreat chain of being,ä with modern humans the pinnacle of evolution.

  6:18

Conversation 2

A  series of consequences follow from acknowledging that humans are part of the natural world, says Dr. Tattersall, confident that human consciousness itself is part of the evolutionary process. He describes competition among human species. Using the fossil record, he assures us that the co-existence of multiple human species on the planet was the rule, drawing startling conclusions from todayâs dramatic exception -- only one human species on earth. He explains why he is confident Neanderthals were a separate and distinct species and describes their extinction. Dr. Tattersall distinguishes between anatomically and behaviorally modern humans, outlining how complex it is to define a species.

  11:20

Conversation 3

Dr. Tattersall describes the process by which paleoanthropologists work. Reminding us that modern humans may be atypical hominids, he urges caution applying our experience, knowledge and behavior to reconstructions of other species. He explains how one can be a hominid (a zoological family 5 million years old according to thefossil record) and not be like modern humans. He explains his belief that it is correct as well as respectful to treat Neanderthals as a separate species, then enumerates features unique to homo sapiens and to Neanderthals. Homo sapiens, he says, may well not be immune to the triage effect which has ended all other hominids. He again challenges the idea that evolution is linear, confident that nature is an ongoing drama of species with no predetermined end.

  9:54

Conversation 4

Dr. Tattersall compares adaptation to exaptation, defining the latter and using examples to show how it helps us better understand what distinguishes modern humans from others. He discusses human speech. Modern humans, he says, have looked (anatomically) the way we do for at least 100,000 years. However, the archaeological record shows recognizably modern (behavioral) complexities arising only between 60 and 40,000 years ago, even though hominid dependence on tools can be discerned 2.5 million years ago. Dr. Tattersall assures us that innovation in human evolution has been relatively rare and episodic, with no guarantees of what comes next. He compares what he is confident are the relative abilities of apes and early toolmaking humans.

  11:57

Conversation 5

Comparing his technical preoccupation with human fossils to their inherent beauty, Dr. Tattersall describes the progress that has been made in using the fossil record to understand where we came from. The real fascination, he says, is how we acquired consciousness. He elaborates, with descriptions of 4 major steps in human toolmaking -- each step embodying some kind of cognitive leap -- prior to the agricultural revolution. He considers where artistry came from. ÊHe summarizes and gives examples of what currently is known about when modern human anatomy and behavior arose and how this has been discerned

  11:07

Conversation 6

Language, Dr. Tattersall maintains, is currently our best candidate for the factor which released our brain's capacity for symbolic thought. He expands, describing how implications are drawn. He reminds us of our constraints in trying to think about pre-linguistic consciousness in modern humans. He describes humans (Neanderthals) who he asserts did very well without language for a very long time, relying instead on sophisticated, intuitive brain processes.

  5:09

Acknowledgements