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Topic 153: William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #26 of 84: Jeff Dooley (dooley) Sun 30 Jun 02 17:19
permalink #26 of 84: Jeff Dooley (dooley) Sun 30 Jun 02 17:19
You seem to take a cynical view of the prospects for robust political support for the kind of research that would draw us closer to knowing when we might be approaching a danger zone, wihtin which an event like a bad el Nino might push us over the edge into cool dry. Or for how to manipulate climate to stay safely out of shooting range. Since you probably wrote (for instance) "know-nothing president and do-nothing congress" 1-2 years ago, what is your assessment today of the political support for helpful research, and is there any increasing interest among scientists in Europe, which would be geatly stressed after a cool-dry flip?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #27 of 84: William Calvin (william-calvin) Sun 30 Jun 02 20:57
permalink #27 of 84: William Calvin (william-calvin) Sun 30 Jun 02 20:57
Not cynical, I hope (I spend too much time trying to point out all the useful things that could be done). People naturally think in the short term, not much beyond the lives of their children and grandchildren. And some of them (say, Mr. Reagan's interior secretary, James Watt) think the world's time is so short that conservation doesn't matter. It's the responsibility of political leaders to take a longer view. And that of authors and the media to help persuade the public that there is more to life than cheap gas and low taxes.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #28 of 84: Andrew Alden (alden) Sun 30 Jun 02 21:26
permalink #28 of 84: Andrew Alden (alden) Sun 30 Jun 02 21:26
When I read that passage (it's on p. 280 of the book, at the end of "How we might stabilize climate"), I also wondered when you wrote it. This passage is a scenario like our current "know-something-do-nothing" state of affairs, what you call "Know Nothing, Do Nothing." In this scenario, short-sighted leaders "have enough influence to create starvation budgets for the relevant science agencies," call for blue-ribbon papers over and over, etc. "In the USA, all it takes is either a know-nothing President or a do-nothing Congress." The Bush administration is close to know-nothing when it comes to climate change--though people see Bush in action and think things are worse than they are. And Congress has been eager to fund science agencies well beyond what the President proposes. But my heart was in my mouth this year when the president asked to maim the US Geological Survey and grossly increase the health agencies' budgets instead. Those of us who understand the long-term needs of civilization must continue to teach and to make our voices heard. In your book you speak often of climate flip-flops, how conditions across very large regions switch from warm-wet to cold-dry within a decade. Whole nations would undergo persistent, total crop failures. You say that these sudden changes have happened hundreds of times during the last 3 million years or so. Has it really been hundreds? And if so, why has it been so long since the last one?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #29 of 84: William Calvin (william-calvin) Mon 1 Jul 02 16:59
permalink #29 of 84: William Calvin (william-calvin) Mon 1 Jul 02 16:59
The really big flips, sudden each way, are the Dansgaard-Oeschger events, of which 20 are numbered between 77k and 12k years ago. There are many smaller, shorter events in that period which would be just as disrupting to an agricultural house-of-cards civilizatgion. Then there are the Heinrich events (ice rafting across the Atlantic that more thoroughly shuts down the Atlantic heat conveyor) associated with the depths of the cool-dry cycle. The Heinrich events go back to 1.1 million years ago. In saying "hundreds," I am assuming that the D-O's are likely occurring in that 1.1 myr period with the H` events. Why not since the Younger Dryas (the most recent D-O at 12,800-11,500 years ago)? The 8,200 year event (about 3degC cooling, recovering exponentially within 200 years) was definitely a meltwater event in the Labrador Sea. So we've had 8,000 years without these suddent events that were otherwise occurring every few thousand years. Most people think that the lack of them is because the heavily-glaciated times have more feedbacks and more meltwater events. But I worry that we're vulnerable even without a Canadian and Scandanavian ice heap. The last warm period ended suddenly. And there is good evidence of a cooling event about 125,000 years ago in the midst of the prior warm period, from which it recovered; the ice cores are not in agreement about that event, so we don't know how fast it was, just from the coral records of sea-level down and back up.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #30 of 84: Jeff Dooley (dooley) Mon 1 Jul 02 17:08
permalink #30 of 84: Jeff Dooley (dooley) Mon 1 Jul 02 17:08
You advise that we work extra hard to avoid slipping into a warming-induced cool-dry period because once established cool-dry is difficult to reverse. I think i remember you saying late in the book that volcano emitted CO2 is thought to account for sudden flips back to a warmer regime. Is this the major trigger for squirming out of cool-dry, or have there been other possibilities?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #31 of 84: William Calvin (william-calvin) Mon 1 Jul 02 20:40
permalink #31 of 84: William Calvin (william-calvin) Mon 1 Jul 02 20:40
No, CO2 is a mechanism for getting out of the Snowball Earth episodes, last seen in precambrian times. Cool-dry is difficult to reverse, at least regarding the thermohaline shutdown which has a hysteresis loop. But no one really understands the abrupt rewarming; what is better understood is the abrupt cooling mechanism. My guess is that both are atmospheric wind rearrangements triggered by sea-surface temperature distributions, which in turn affects the average humidity. Failure and reinstatement of the thermohaline aspect may not be the suddenness we see, just part of the setup. Sorry for all the technical language. I can avoid it more easily about the anthropology!
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #32 of 84: Andrew Alden (alden) Tue 2 Jul 02 21:09
permalink #32 of 84: Andrew Alden (alden) Tue 2 Jul 02 21:09
On the subject of anthropology, then, your book presents some things I hadn't known before. For a long time I've tended to ignore news about early hominids because it seemed like every new skull was declared a new species, or demolished an existing theory. But the picture you paint is one of burgeoning hominid species over the last 3 million years. The slender tree of evolution that led to our single twig, Homo sapiens, was truly more like a bush. Is the picture really becoming clear? Did humanlike species arise easily, rather than one single human species evolving without speciation?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #33 of 84: William Calvin (william-calvin) Wed 3 Jul 02 08:22
permalink #33 of 84: William Calvin (william-calvin) Wed 3 Jul 02 08:22
I decided to avoid the arguments about each different species named for the hominids. Nothing dates a book faster than that! But I think that there were probably a dozen species on the line from the chimp common ancestor to us. (So does Ian Tattersall in Becoming Human.) Speciation in the record is a subtle thing to establish; reproductive isolation cannot be seen, and that's what counts as a ratchet to the Darwinian crank. It's a high degree of reproductive failure when two groups try to interbreed that prevents backsliding when immigrants arrive in an isolated valley or island where natural selection has substantially biased the population's characteristics. Speciation prevents backsliding. And since hominid evolution is relatively fast (especially the brain size increases in the last million years), I'd assume that there have been a number of speciations (reproductive isolations, perhaps without the obvious anatomical changes that a paleontologist would use to peg a new species).
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #34 of 84: Andrew Alden (alden) Wed 3 Jul 02 11:25
permalink #34 of 84: Andrew Alden (alden) Wed 3 Jul 02 11:25
"...a high degree of failure when two groups try to interbreed" That struck me as a great simplification, and a useful one, when we think about the origin of a new species. Part of the trouble with Darwin's picture of speciation was that nobody had a deep enough understanding of genetics in his time. He could only point to examples like the horse and the ass, which yield sterile offspring between species. But clearly horses and asses are different "kinds," so you could say his example didn't really prove anything. Their genomes are incompatible, just like ours and bonobos. But something you point out is that there are many subtle ways that different groups within the same species ACT like separate species. This was new to me--but then I would have the paleontologist's view: if the bones don't show it, we can't claim it. You have the biologist's view: species are as species do.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #35 of 84: William Calvin (william-calvin) Thu 4 Jul 02 14:50
permalink #35 of 84: William Calvin (william-calvin) Thu 4 Jul 02 14:50
There are two disjoint concepts of a species: what looks "different enough" and when a population no longer interbreeds effectively with its parent species (reproductive isolation). On the first definition, paleontoologists digging up a pet cemetery would decide there were dozens of dog species. On the second definition, they're all one species because they all interbreed, yielding mongrels (what the original "breed" likely looked like). Similarly, there are some species of cormorants that look alike but are really separate species (they specialize in different niches). The paleontologists are doing the best they can. Soon, extracting DNA will allow a better method of judging fossils.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #36 of 84: Andrew Alden (alden) Thu 4 Jul 02 15:24
permalink #36 of 84: Andrew Alden (alden) Thu 4 Jul 02 15:24
It intrigued me that you cited medical evidence that different groups of people have trouble "cross-breeding" and that some unexpected things can interfere with normal reproduction, even things like drinking water. And here I thought there was something called "hybrid vigor." Is that a fallacy?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #37 of 84: William Calvin (william-calvin) Thu 4 Jul 02 21:59
permalink #37 of 84: William Calvin (william-calvin) Thu 4 Jul 02 21:59
No, I said that one could imagine groups of hominids that began to have a lot of reproductive failures when interbreedeing. I had spontaneous abortions in mind (things like smoking can triple the spontaneous abortion rate, so perhaps aspects of diet could do it too). But rearing children successfully is part of it, and if between-group pairings are less like to successfully support a child up to reproductive age, that would contribute to species-like separation too. Then too, kids tend to beat up a child that looks funny. Culture might be as important as biology in effectively causing reproductive isolation.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #38 of 84: flying jenny (jenslobodin) Fri 5 Jul 02 03:32
permalink #38 of 84: flying jenny (jenslobodin) Fri 5 Jul 02 03:32
this is great, fascinating. just wanted to let you know you're talking to more of us than you might think. i'm reading the book; no questions yet, though i'm sure to have some soon. thanks, both of you!
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #39 of 84: William Calvin (william-calvin) Fri 5 Jul 02 08:46
permalink #39 of 84: William Calvin (william-calvin) Fri 5 Jul 02 08:46
FYI, the entire text is at www.williamcalvin.com.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #40 of 84: Linda Castellani (castle) Fri 5 Jul 02 13:21
permalink #40 of 84: Linda Castellani (castle) Fri 5 Jul 02 13:21
And if anyone who is not a WELL member wants to participate in this discussion, send your comments and questions to inkwell-hosts@well.com and we will see that your words get posted.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #41 of 84: Andrew Alden (alden) Fri 5 Jul 02 16:35
permalink #41 of 84: Andrew Alden (alden) Fri 5 Jul 02 16:35
Culture as a force in speciation... That reminds me of another point you make, which is about adaptation. There's a line of argument among creationists that living things can't just grow new parts, like the eye-- they are so unlikely to happen by normal variation or by mutation (which they love to call "random chance") that they must have been created specifically. You point out that behaviors favor certain adaptations and not others. If the ancestors of moles weren't already digging in the soil for their food, then their amazing forepaws wouldn't have been favored. The critters didn't suddenly find themselves born with them and then decide to go digging. So what were we doing with our prehistoric lives that favored great big brains?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #42 of 84: Brian Slesinsky (bslesins) Fri 5 Jul 02 21:12
permalink #42 of 84: Brian Slesinsky (bslesins) Fri 5 Jul 02 21:12
(BTW, the front page for the book doesn't render correctly under Mozilla 1.0.)
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #43 of 84: William Calvin (william-calvin) Sat 6 Jul 02 11:27
permalink #43 of 84: William Calvin (william-calvin) Sat 6 Jul 02 11:27
Apropos the creationist's "common sense" argument re complicated assemblies, I defer to Richard Dawkins, <i>River Out of Eden </i>(Science Masters, BasicBooks, 1995). "Never say, and never take seriously anybody who says, `I cannot believe that so-and-so could have evolved by gradual selection.' I have dubbed this kind of fallacy `the Argument from Personal Incredulity.' Time and again, it has proved the prelude to an intellectual banana-skin experience." The 8-hr <i>Evolution</i> series had an excellent segment on the evolution of the camera-like aspects of the eye, showing simple intermediate steps thatw ere themselves useful. Brain growth is gradual, and their argument really doesn't apply to it. But the nature of the selective pressures isn't really settled yet; I explain in the book why I think that "intelligence" as an explanation is unsatisfactory and unsatisfying.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #44 of 84: William Calvin (william-calvin) Sat 6 Jul 02 11:34
permalink #44 of 84: William Calvin (william-calvin) Sat 6 Jul 02 11:34
The other aspect of common sense misleading people is that we tend to expect straight-line evolution, say bigger brains are more intelligent, smarter is better, and so bigger is better. Over and over. But in evolution, you often have a mix of causes. That's why I like my curb-cut metaphor so much. Initially wheelchair sue paid for the curb cuts. But once in place, there were many secondary "free" uses. At airports, the wheeled suitcases have, in effect, paid for widening the curb ciuts to be as wide as the crosswalk. Still, most of the uses (bicycles, skate boards, grocery carts) are free. I think that when we finally understand big brain evolution, we will appreciate that there were initial causes, secondary improvements for other reasons, and so forth.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #45 of 84: Fuzzy Logic (phred) Sun 7 Jul 02 18:26
permalink #45 of 84: Fuzzy Logic (phred) Sun 7 Jul 02 18:26
The curb cut thing comes to mind every time I nearly get run over on Portland's downtown sidewalks by a zooming bicycle rider. We have a city ordinance that restricts bicycles to the street downtown except for police and quasi-police (our downtown "improvement association" gendarmes). So every innovation carries within it unexpected social complification :) But more seriously... I'm glad to see the return to more straightforward Darwinian thought recently. The notion that alden mentioned of the term "natural selection" too readily bringing to mind the notion of a "selector" -- which leads to the current oddball fad of "intelligent design" is one dead end. Another is a kind of simplistic reductionism embodied, for me anyway, by the so-called Eve Hypothesis. I'm not quite sure why this rather ordinary conclusion from studies of human molecular evolution hit such a huge public nerve starting in the late 1980s. It's been helpful recently to read Ernst Mayr's "What Evolution Is," a very clear general-readership summary of current Darwinian science. (Just shows you what 97 years of experience can bring out ...!) What I wonder if you'd comment on, though, is the prospects for our culture, science and technology to change direction to be more in alignment with the natural cycles our economy and lives are embedded in, with global climate of course being critical. I was struck by your reference to the fact that we don't plan well, at least in modern society, much past the time horizon of our children or grandchildren's lives, and yet atmospheric CO2 sets in motion a hysteresis effect of at least that long. Many "indigenous" societies have belief systems predicated on a much longer view ("the seventh generation of the seventh generation, etc.) and while it's likely that belief and practice weren't exactly aligned there either, perhaps we've lost something in the embrace of technology over all. The good thinkers in ecological economics refer to this as the "generational equity" issue, and it confounds some of the fundamental assumptions in our societal planning such as the adoption of an economic discount rate that is fixed and essentially indefinite. On that basis, anything happening more than 20 or 30 years from now is seen, on a planning basis using the conventional tools, as basically having no present value. So I guess my question is, we have all this science on global climate change now, and we have a pretty full plate on the near-term research agenda. But for those of us who are not climate scientists -- where to from here, and how can the science be tied more tightly to governance without it becoming the absurd dualistic political football game that climate has been over the last decade?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #46 of 84: William Calvin (william-calvin) Mon 8 Jul 02 08:34
permalink #46 of 84: William Calvin (william-calvin) Mon 8 Jul 02 08:34
Hi, phred! The main long-term public policy embraced by segments of the public is "balance." Protecting endangered species, keeping CO2 from rising, keeping habitat for natural predators like wolves, etc. All valuable in their own right, but hanging them on "balance" gets into trouble with the notion that there is no steady-state in real life, that things are always in the process of changing. Dynamics, in short, not statics. Near-static is our main approach to it, as in the ramp-up-the-thermostat metaphor for global warming (rather than the metaphor of the light switch that simply flips into a new state at some point). So we need some improved metaphors all around. That's one of the things that I try to do in the book, for both biological evolution and for climate change.gh
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #47 of 84: Andrew Alden (alden) Mon 8 Jul 02 12:31
permalink #47 of 84: Andrew Alden (alden) Mon 8 Jul 02 12:31
I like that aspect of "A Brain for All Seasons" a lot, the new and improved metaphors. It helps that you have a scientist's proper understanding of what lies behind the metaphors. You have an unusually broad range for a scientist too, in my experience. An appreciation for scenarios and contingencies is a key ingredient in historical sciences and life science, which is where the subject of brain evolution lives. Fluency in physical thinking and analysis is a mainstay of geophysical subjects like paleoclimatology and oceanography, which is where the greenhouse problem lives. You might call the two approaches historical and numerical. I would say that we badly need more people who can combine the two, whether it's interdisciplinary scientists like yourself or writers who can make them both sexy--like yourself. Are our universities up to this task?
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #48 of 84: Indigo Mallard (blueduck) Mon 8 Jul 02 13:26
permalink #48 of 84: Indigo Mallard (blueduck) Mon 8 Jul 02 13:26
Reading over the part about altruism evolution versus freeloaders - I was reminded of Turnbull's study of the Kikuyu who are not altruistic, but their system works for survival of the tribe.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #49 of 84: William Calvin (william-calvin) Mon 8 Jul 02 22:16
permalink #49 of 84: William Calvin (william-calvin) Mon 8 Jul 02 22:16
andrew asks if universities are up to the task of formenting multidisciplinary overviews. Generally not. I manage only because I mostly stay off the payroll, thanks to royalties. The basic problem is grants, the lifeblood of lab, field, and simulation research. Grants are awarded by review groups that have a focus; if the grant only "speaks" to several members of the committee, other grants more focussed on the committee's true expertise will get more votes. People vote for what they can understand and appreciate. There are other causes of specialization, such as only being able to keep up with a narrow segment of a field in any depth. SO many multidisciplinary things fall between the cracks. And if they don't fit the lab- or field-research paradigm, they have even rougher going. But smaller foundations are more open to supporting overview-type stuff such as mine. Unfortunately, what one needs is a job with overview as a mandate, not just a $20k foundation grant here and there.
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William Calvin - A Brain for All Seasons: Human Evolution and Abrupt Climate Change
permalink #50 of 84: Indigo Mallard (blueduck) Tue 9 Jul 02 08:21
permalink #50 of 84: Indigo Mallard (blueduck) Tue 9 Jul 02 08:21
Finished the book. I would say that my primary contentions are with the techno fixes. Based on what I know about this, I don't think those are going to work. Wishful thinking to believe that a little dynamite, for example, is going to be able to stop fresh water flooding as described. The kicker here, though, is the extent of the greenhouse effect. We haven't had this much greenhouse chemistry going on in the last few million years.
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