New Year's predictions, 2007 edition
It's a hazardous business, making predictions -- all the moreso because New Year's predictions have a deadline. If they don't happen this year, well, that's too bad, because we'll be checking back a year from now to see how well you did.
Last year, I did pretty well. My 2006 predictions are listed below. I ordered them originally "from most certain to most speculative". As you can see, the first five (i.e., the more "certain" ones) all came true; the last five (i.e., the wild-arsed speculations) didn't. So let's check them out:
- 10. We will see a name for the Flores pathology. OK, we got several names, and the issue is far from settled, but this was the year that the Homo floresiensis doubters struck with their papers on the remains.
- 9. There will be two Neandertal genome-related announcements. I undercalled this, since there were three -- the initial announcement in June of the Neandertal Genome project, the announcement and publication in November of the initial sequence results, and the announcement about possible introgression of microcephalin.
- 8. No Ardipithecus. Sometimes, predictions write themselves.
- 7. "Population cluster" will become the new "race". This one is debatable, but enough papers on multi-ethnic SNPs have used the term this year, that I think it is emerging as the replacement for the race concept for a certain class of geneticists. I expect it will continue -- "cluster" has such a neutral computer-program-centric connotation, that people like to use it.
- 6. There will be another paper (yes, besides the one last month) using genetics to estimate the time of the human-chimpanzee divergence. The date will be 5 million to 7 million years ago. Oh, my. There have been bigger messes than the Patterson et al. 2006 paper, but not many. Yes, it was yet another paper with a 5-million to 7-million-year-old divergence, but it had so much more!
- 5. Evidence of recent selection will be found for several Y chromosome genes. Wishful thinking or prediction for the next year? You decide!
- 4. Sahelanthropus postcrania will be published. This one didn't happen this year, but I'm carrying it over onto the 2007 list.
- 3. There will be an ancient DNA announcement from China. Someday it will happen, but not this year or next.
- 2. StW 573 will be proposed as a new species ancestral to all later hominids. Well, we got the opposite -- with a new younger date, StW 573 was proposed as the ancestor of...nobody! Which was by far the smaller of the redating stories this year.
- 1. A Hawks weblog post will be cited in a peer-reviewed research paper. We can only hope this happens in the coming year, but carrying it over just seems desperate...
- BONUS: A new Georgian hominid will be a robust australopithecine. I still think somebody will find an australopithecine outside Africa in the next decade, but it's not to be from Dmanisi -- the hominids are too localized in a single feature.
So that should give some indication of how to read the list for the next year. I'm listing from more certain to more speculative again, and again I'm excluding most of my own work. The main effect of this is just that I'm not including secrets that I know will be coming out this year. Once again, the predictions are Delphic -- if only I were cleverer, I could make them come out right no matter what!
- 10. Sahelanthropus postcrania will be published.
- 9. Two words: Holocene evolution.
- 8. Despite (or because of) the success of the Neandertal genome project, there will be no genetics of any kind published on early modern skeletal material.
- 7. The mitochondrial history of human dispersals will become more and more detailed, but no paper will test against other loci.
- 6. Another (yes, another) paper about the chimpanzee-human divergence will peg it between 5 and 7 million years ago.
- 5. Three papers with new Ethiopian fossils.
- 4. Another early Upper Paleolithic specimen will emerge from a museum collection.
- 3. A big year for Miocene apes, which will look increasingly important in the story of human brain evolution.
- 2. Maturation rate in early Homo becomes a dead issue, because of the variation in dental and skeletal maturation in living people.
- 1. The year will end without a single new hominid species having been named.
- BONUS: A dramatic development in the problem of pre-2.0-million-year-old Homo.
I ended the year with just a shade fewer than 1 million visits since last January 1. The Neandertal women brought me over 10,000 readers in a single day -- the most ever. I know a few of the big stories from the coming year, but there will be many more that nobody can predict. There's no doubt in my mind that 2007 will be a big year!
Quote of the day
Ann Althouse, deep in the comments wrapping a One Flew Over the Cuckoo's Nest metaphor:
Academia is, apparently, a mad house, and this blog is my bus ride and fishing expedition.
Theme of the year: be a gap junction
I think it's a good idea to set out with a purpose for the new year. If there is one thing that describes the important work underway, it is bridging the gap between the natural history of humans and our molecular makeup.
Except, well, "bridging the gap" is way too overused. It's like "building bridges to the 21st century" and the like. Plus, it has this huge structural connotation. It takes a lot of people working together to build a bridge. Everybody knows that.
That's why it's such a good metaphor: plausible deniability. "Hey, the bridge didn't get built? What are you looking at me for? I'm supposed to build a bridge all by myself? Get outta here!"
So I'm picking "be a gap junction". Let's look at what they are:
A gap junction is a junction between certain animal cell-types that allows different molecules and ions to pass freely between cells. The junction connects the cytoplasm of cells.
It makes a certain kind of connection between two things, allowing things to flow between them -- like a bridge. But it's tiny and operates rapidly, on a molecular scale. It's an individual, although it may work collectively with others.
For me, the gap junction is a perfect embodiment of this year's theme -- making connections between human molecular evolution and human natural history.
The evolution of our molecules has been coming rapidly into focus. Much more information about the broad scale of human molecular evolution will be coming online this year. There aren't so many people who can take this information and find the aspects of human natural history that it can address. The important changes in human evolution -- beyond the brain to other aspects of our biology, such as life history, diet, and social strategies -- are just as much a black box to many molecular biologists as genomics has become to many traditional anthropologists. There is something interesting there, no doubt, but what is it?
That's my field. That's what I'm working on. It's really exciting.
I bring this up not only because of the New Year, but also because of this article by Carl Zimmer in the current PLoS Computational Biology. It may not be a journal you typically read, but it's open access and worth a look.
Zimmer sets out to describe the dichotomy between natural historians -- paleontologists, field biologists, ecologists, and the like -- and molecular biologists. He gives a quick account of the hippo-whale problem, but it is in no sense exceptional -- anthropology has it's own examples of phylogenetic discord between molecular and paleontological specialists, such as Ramapithecus. The point is that there are increasingly two kinds of data -- molecular and natural historical -- and nobody is a specialist in both:
This experience made a strong impression on me. I was struck by the divide between these two kinds of biologists. Each group had a profound confidence in their own sources of information, and an abiding skepticism about the other's. As I learned more about the history of modern biology, I realized that this rift did not begin in the 1990s. It was already present in the 1950s, as molecular biologists began championing their new science over more traditional ways of understanding life.
Harvard University's biology department was a microcosm of this conflict. James Watson, fresh from discovering the structure of DNA, breezed into the department in 1956 with revolution on his mind. âIt was time to sweep beyond mere description of animals and plants and move into a new biology based on chemistry and physics,â as Watson's biographer, Victor McElheny, writes [4].
Needless to say, the Harvard naturalists were not happy. Edward O. Wilson, entomologist, ecologist, and sociobiologist, pushed back hard. âWatson, having risen to historic fame at an early age, became the Caligula of biology,â he writes in his autobiography, Naturalist. âIt was foolish, we argued, to ignore principles and methodologies distinctive to the organism, population, and ecosystem, while waiting for a still formless and unproved molecular futureâ [5]. The struggle only ended when Harvard's biologists agreed to split their department in two.
The Watson-Wilson dichotomy is an emblematic example, in that the real problem is as more due to personality and temperament than to the inherent difficulty of the subject. How many molecular biologists are requiring their students to learn about the fossil record? How many natural historians have been requiring molecular biology and genetics of their students? The answer is not zero -- indeed, far from it. But one or two courses in genetics generally give a good grounding in the molecular biology of ten years prior. The fossil record doesn't change so quickly, but a full theoretical grounding in the means of analyzing fossil samples takes a long time. It is very easy to pick and choose hypotheses and worry about the niggling doubts later.
As Zimmer points out, this problem of training leads to absurd extremes. Imagine a paper summarizing the evolution of a mammalian family -- one richly represented in the fossil record -- that doesn't include a single fossil.
One example of this new ambition was a paper published earlier this year on the evolution of cats [6]. The scientists offered a sweeping scenario for cat evolution, complete with migrations of cats out of Asia into the New World and back, along with the emergence of the major groups of felids, ranging from ocelots to bobcats to lions. The scientists based their scenario entirely on an analysis of cat DNA. They did not consider a single fossil of a cat, nor did they have a paleontologist expert on cats as a coauthor. Cat fossil experts inform me that fossils of true cats as old as 17 million years have been discovered in North America. The geneticists put the arrival of cats in North America at only 8 million years ago. Whether or not the DNA results are correct, it is striking that the report does not even mention the existence of fossils that do not fit the pattern.
Zimmer has written much about natural history, and has great sympathy for the paleontologists he has worked with. So the article's theme is the value of natural history knowledge as applied to molecular information (he refers to this as "computational biology", but that gives the lab guys short shrift). As an example, he describes the evolution of early vertebrates: Molecular information shows evidence for genome duplication between present-day jawed vertebrates and the agnathans. As Zimmer points out, this led the hypothesis of a sudden burst of evolution leading to the features of jawed vertebrates, but paleontology shows that the jawed vertebrates emerged gradually in the fossil record over a long time, with different features emerging at different times. In this instance, a "striking" hypothesis from considering molecular features in isolation is easily disproved by looking that the fossil record.
This is the frontier of human evolution: integrating the data from human genomics with our knowledge of human prehistory. The days when we had to argue about the phylogeny of a single gene are long behind us. Anthropological genomics is about being a "gap junction" -- taking specialist knowledge of human prehistory and applying molecular information to test evolutionary hypotheses.
And if single genes are behind us, so are single events. "Out of Africa" doesn't explain everything, nor does the origin of Homo, the origin of the hominids, or any other single event. When we were limited to one gene, we were limited to one event, more or less. More than likely, that one event really was about natural selection and the phenotypic expression (or linkage) of the gene. Genomics has opened new doors that let us examine the evolution of phenotypes over hundreds of thousands of years. We can examine the differences between loci in their genealogical patterns, and in some cases we can link those differences to demographic events.
It's about finding diversity among the evolutionary histories of different genes, and linking that diversity to the diverse causes of our own evolution. This will be the year that a true anthropological genomics begins to emerge.
References:
Zimmer C (2006) The Genome: An Outsider's View. PLoS Comput Biol 2(12): e156 DOI: 10.1371/journal.pcbi.0020156
Greetings, meat machines, it's a New Year
I was going to make it a quote of the day, but this column by NYT writer Dennis Overbye is worth reading in full. It's about the march of science against free will:
"If people freak at evolution, etc.," [philosopher of science Michael Silberstein] wrote in an e-mail message, "how much more will they freak if scientists and philosophers tell them they are nothing more than sophisticated meat machines, and is that conclusion now clearly warranted or is it premature?"
As Overbye points out, it's far from a new problem:
That is hardly a new thought. The German philosopher Arthur Schopenhauer said, as Einstein paraphrased it, that "a human can very well do what he wants, but cannot will what he wants."
Einstein, among others, found that a comforting idea. "This knowledge of the non-freedom of the will protects me from losing my good humor and taking much too seriously myself and my fellow humans as acting and judging individuals," he said.
Well, a hopeful fatalism is one of the attractions of a belief in predestination. But personally, I think when quantum physicists start talking about free will, it is just anthropology-envy. Hey, if you want to study human action, then make a proper study of it! You don't need Gödel, for goodness' sake! That's just a way to say, "Harrumph, the ancient experts show us by long proof that the problem of free will lies deep in a paradoxical enigma. Murmpheaoww! Give me another cigar!"
It's like your doctor quoting Galen when he prescribes an antibiotic. Totally irrelevant!
I don't really think that the central metaphysical question here -- is human action something other than deterministic or random? -- is one that most of us worry too much about. Most people who are thinking about "free will" have in mind things like whether SS stormtroopers were responsible for various reprehensible actions, or whether "just following orders" is a valid excuse.
To my mind, if you've gone all the way to the subatomic level to talk about free will, then you've already answered the really important questions. That is, unless you want to posit an "obey-evil-dictator" neutrino!
Anyway, the article presents a good basic-level overview of Libet's experiments and various follow-ons. The problem is when it derails into whether Cretans are liars and other detours. Seth Lloyd is extensively quoted about whether computer laptops have free will of a sort. Well, they probably do, and in the human sense, besides! Who hasn't thought that her own computer is deliberately thwarting it's master's subtle plans? That's probably more evidence than we require to assume that other people have free will!
I can understand why one might object to a human-computer analogy, but a human brain that is a product of evolution must be computer-like in some important ways. The other side of that analogy is that computers are like brains in some important ways.
"Free will" doesn't mean "unpredictable action", after all. If it did, there would be no sense in predicting anything for the coming year. Which is what I'm setting my mind to this morning!
Why else would I start the year with an overly-glib post about an ancient philosophical problem?
John Hawks Department of Anthropology
University of Wisconsin—Madison
Copyright © 2007 John Hawks