Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
The best kitteh ever is, of course, Peyton, the philosophical cat, who has previously contributed to our discussions here at WEIT on morality, ethics, and epistemology. But, as a semi-regular contributor, she is ineligible for the Kitteh Contest, so readers should submit their nominees to Jerry by 5 PM December 1. Here again is Jerry’s picture of her
Peyton, the philosophical cat.
and some new video.
If she had not, once again, been displaying some of Pinker’s rudimentary moral sentiments, my foot would have been a bloody mess.
Every scientist I know has 1, cool research and 2, a ‘cool’ aspect of their lives. If you genuinely want scientists, as a profession, to become ‘cool’ like rock stars, you need to start with getting scientists to connect their research to their ‘cool’ selves. [n.b. Abbeh’s is kick boxing]. As in, going out and being a part of their communities. Most people dont know a scientist, so get out there and mingle.
Or you know what? Maybe just accept people how they are, cool or not. Appreciate their science and their contributions to society and humanity, just like I appreciate the girl helping me find the toothpaste on sale at CVS, or the guy changing the oil in my car (I DO NOT UNDERSTAND CARS), or the cops trying to find my stalker.
Not everyone has to fucking be ‘cool’.
‘Cool’ is superficial crap that means nothing when contrasted with the ability to help people, in any capacity.
I’m on board with ERV here. In the absence of any evidence that these campaigns do a lot for science, it’s annoying to hear the Great Communicators tell us, “This is how it must be done.” Rather than stand next to Justin Bieber and become cool via osmosis (gag), I prefer to write popular books and lecture to lay audiences.
As I wrote in my review for Science of Mooney and Kirshenbaum’s Unscientific America, which also promoted a “cool science” approach (Mooney is a major force behind the GQ scientist/rock star fusion):
More than at any time in my life, I see Americans awash in popular science. Bookstores teem with volumes by Stephen Gould, Steven Pinker, Brian Greene, Steven Weinberg, Richard Dawkins, Michio Kaku, Edward O. Wilson, and Jared Diamond; natural history museums have become user friendly; and entire television channels are devoted to science and nature. Science education is readily available to anyone who is curious. And yes, we scientists need—and want—to share our love of science with the public. Still, we must compete with the infinite variety of claims on people’s time and interests, including sports, movies, and reality shows. No matter how much atheists stifle themselves, no matter how many scientists reach out to the public via new media, we may not find the appetite for science infinitely elastic. This does not mean, of course, that we should refrain from feeding it. But figuring out where and how to intervene will take a lot more work than the shallow and unreflective analysis of Unscientific America.
I’ve disabled comments on this post for two reasons. First, please be sure to comment on Matthew Cobb’s post below; he’s surveying what readers think of the term “instinct”. Second, you should use your time to photograph your kitteh and write a paragraph for the Awesome Kitteh Contest. The contest closes at 5 p.m. on December 1, and the entries are rolling in. Today’s the day to get that rare shot of Fluffy with a turkey leg.
I’d like to enroll the readers of WEIT in a bit of research. I’m currently applying for a grant looking at the concept of “instinct”. Although “instinct” is widely used in ordinary speech to describe behaviours or processes that appear to be both widespread and consistent between members of the same species (thus a cat has a “hunting instinct”, while bees “instinctively” sting a threatening animal, and humans learn to speak “instinctively”), in science, however, the term was abandoned in the 1950s.
Of course, this does not mean that we think that there are no innate or genetically determined behaviours, merely that “instinct” isn’t a useful way of describing them. So there’s an apparent mis-match between scientific speech/concepts and that used by other people. That’s one of the things I want to investigate.
To explore what people outside the animal behaviour world think “instinct” means, I will set up focus groups, questionnaires and so on. As an initial step on this road – and to flesh out my grant proposal! – I’d like WEIT readers to make comments below about what *you* think “instinct” means. If you accept that that some behaviours are innate, is “instinct” simply shorthand for this, or does it mean something different to you?
While in Colombia last week, Jerry directed my attention to a paper by Roy Britten (abstract only free) in that week’s issue of the Proceedings of the National Academy of Sciences. Britten is a venerable figure in evolutionary molecular genetics, one of the pioneers of DNA-DNA hybridization who helped elucidate the structure of the genome long before sequencing was possible. The paper was indeed interesting. This post is a bit longer and more data-and-analysis-laden than usual, but I think the paper merits discussion.
Britten summarizes his latest paper’s conclusions succinctly:
The aim of this paper is an explanation for the high speed of evolution of the human lineage, which has been exceptional compared with other animals. The high speed of evolution of human lineage brain size is recognized by comparison of fossil brain sizes (1, 2). Evolution of the lineage leading to humans during the last several million years was striking. … A major source of variation [for brain evolution] has been the insertion of transposable elements (TEs).
He goes on to note that besides rapid brain evolution, humans have many TE insertions. For him
This is an extraordinary correlation. Human evolution has been rapid, particularly brain evolution in the last several million years. It is the only species known to make such rapid evolutionary progress. Now it is shown that human is the only species studied to have so many TE insertions. Recognition of this correlation leads to the concept that Alu insertions underlie rapid human evolution.
Importantly, he states up front that:
We believe the brain evolution was due to natural selection and genomic variation.
He is thus not seconding Colin Blakemore’s unwarranted claim that brain size is a neutral character, conferring neither selective advantage nor disadvantage, that must therefore have evolved via genetic drift. Britten is definitely not saying this, and is thus not open to the criticisms of Blakemore made by Jerry (here and here) and John Hawks. Britten thinks a big brain is advantageous.
So, how well supported are the claims he does make? I’d first note that one data point does not a correlation make, especially not an extraordinary one. TE’s, by increasing mutation rates, can certainly increase evolutionary rates, but all sorts of other singular characteristics apply to the Homo lineage. In addition to having many TE’s, they were savannah-dwelling, nearly hairless, bipedal, etc. Which of these correlates with rapid brain growth is the important one? I don’t know, but a more forceful argument than simple occurrence in the same lineage would be needed to establish which is the most likely causal factor.
And what about the factual points? Much of the paper is devoted to establishing the prevalence of TE’s in the human lineage, and I, as at least a first approximation, would yield to Britten’s expertise on this point. What about the rate of brain size evolution? (To be fair, Britten takes his cue here from the literature; the high rate is a premise, not a conclusion.) G.G. Simpson, one of the founders of modern evolutionary biology, spent a major part of his career documenting the variability of evolutionary rates. He showed that there is great variability of evolutionary rates between lineages, among characters within lineages, and within lineages at different times. The following figure is based on an original in Simpson’s 1953 Major Features of Evolution. It shows that the rate of evolution in lungfish was high about 300 million years ago, but not so much at other times (i.e. variation within lineages at different times).
Rate of lungfish evolution, from Mark Ridley's Evolution, 2004.
Historically, claims of human exceptionality have tended to become less exceptional when examined more closely. Huxley’s debate with Owen over the brain is perhaps the classic example: contra Owen, Huxley “showed that the brains of apes and humans were fundamentally similar in every anatomical detail.” Knowing this, I decided to check on this important premise of Britten’s paper. Is the speed of evolution of the human brain “striking”, and “exceptional compared with other animals”? In a word, no: over the last several million years, human brain size has evolved at rates which are typical of paleontologically measured evolutionary rates.
Here’s a graph by John Hawks (using the same or similar data as Lee and Wolpoff, 2003) showing the pattern of change in cranial capacity (on the vertical axis, in cubic centimeters) over the last 2 million years or so.
There are a number of ways of measuring evolutionary rates of morphological features such as cranial capacity. One useful measure is the haldane, developed by Phil Gingerich (1993) of the University of Michigan Museum of Paleontology, based on a suggestion made in 1949 by the original most interesting man in the world, the great geneticist-physiologist-soldier-pacifist-communist-Hindu-atheist-patriot-expatriate J.B.S. Haldane, one of the founders of modern evolutionary theory. The haldane is the change, on a logarithmic scale, of the feature in question in units of the standard deviation (a measure of how variable the feature is), per generation.
Using data from three papers on modern human cranial capacity, I found the average to be 1345 cubic centimeters (cc), calculated as the unweighted average of males and females from the measured populations from Korea, Turkey, and Nigeria (a total sample of 1151). 1.8 million years ago, the cranial capacity of the Homo lineage was 702 cc, calculated as the average of skulls of that age from Perning, Kenya (one each, given by Lee and Wolpoff, 2003), and Dmanisi (three skulls, given by Gabunia et al., 2000, for two of them, and the median of two estimates by Lee, 2005, for the third).
The logarithmic standard deviation is well approximated by the coefficient of variation (CV: the untransformed standard deviation divided by the mean; Lewontin, 1966). The unweighted average CV for the modern humans was .0955, and for the five early Homo it was .1149; averaging, we get .1052.
So, the amount by which cranial capacity has changed on the log scale is ln(1345)-ln(702)=.6502; dividing this by the estimated logarithmic standard deviation, .1052, gives 6.181. In the last 1.8 million years, our cranial capacity has increased about 6 standard deviations. We don’t know generation time for early Homo, but we do know it for modern humans (about 25-30 years) and chimps (19-24 years; Matsumura and Forster, 2008). Using 25 years as an estimate for the whole lineage, we get 72000 generations in the last 1.8 million years, giving an evolutionary rate for brain size of .00008584 (or 10^-4.066) haldanes.
Is this a high rate or a low rate? Neither– it’s absolutely typical for evolutionary rates measured over this generational time scale. Gingerich (2001) compiled a large data set on rates of evolution, measured in haldanes, over a wide variety of time scales. He states:
Macroevolutionary studies yield rates on the order of 10^-2–10^-6 haldanes calculated over intervals of geological time ranging from 10^2–10^6 generations.
If we look more precisely, at about 72000 (10^4.86) generations, we find measured rates of about 10^-3.5 to 10^-6.5. So the rate of human brain evolution is above the median, but nothing “exceptional”. Could this unexceptional result be due to the particular initial time (1.8 mya) selected? What if we looked further back in time? I redid the analysis using an average chimpanzee cranial capacity of 383 cc (McKee et al., 2005), and a divergence time of 6 million years. Using the same logarithmic standard deviation and generation time, we get [ln(1345)-ln(383)]/.1052 = 11.940 standard deviations, nearly twice the 6 standard deviation change in the last 1.8 million years. Dividing by the 6 million years/25 years per generation = 240000 generations gives .00004975 (or 10^-4.3) haldanes. Again, above the median, but nothing exceptional.
So, there’s nothing much remarkable about the speed of human brain size evolution. If the TE’s (or hairlessness or bipedalism or whatever) of the Homo lineage had an effect on human evolution, it was not expressed as an unparalleled increase in the rate of evolution of cranial capacity.
Acer, N., M. Usanmaz, U. Tugay, and T. Ertekin. 2007. Estimation of cranial capacity in 17-26 years old university students. Int. J. Morphol. 25:65-70. pdf
Britten, R.J. 2010. Transposable element insertions have strongly affected human evolution. Proceedings of the National Academy of Science 107:19945-19948.
Gabunia, L., et al. 2000. Earliest Pleistocene hominid cranial remains from Dmanisi, Republic of Georgia: taxonomy, geological setting, and age. Science 288:1019–1025.
Gingerich, P. D. 1993. Quantification and comparison of evolutionary rates. American Journal of Science 293A: 453-478. pdf
Gingerich, P. D. 2001. Rates of evolution on the time scale of the evolutionary process. Genetica 112-113: 127-144. pdf
Haldane, J.B.S. 1949. Suggestions as to quantitative measurement of rates of evolution. Evolution 3:51-56.
Hwang, I.-L., et al. 1995. Study on the adult Korean cranial capacity. Journal of Korean Medical Science 10:239-242. pdf
Matsumura, S. and P. Forster. 2008. Generation time and effective population size in Polar Eskimos. Proc. R. Soc. B (2008) 275:1501–1508. pdf
McKee, J.K., F.E. Poirier, and W.S. McGraw. 2005. Understanding Human Evolution. Pearson, Upper Saddle River, New Jersey.
Lee, S.-H. 2005. Is variation in the cranial capacity of the Dmanisi sample too high to be from a single species? American Journal of Physical Anthropology 127:263–266. pdf
Lee, S.-H. and M.H. Wolpoff. 2003. The pattern of evolution in Pleistocene human brain size. Paleobiology 29:186-196. pdf
Lewontin, R.C. 1966. On the measurement of relative variability. Systematic Zoology 15:141-142.
Odokuma, E.I., P.S. Igbigbi, F.C. Akpuaka, and U. Esigbenu. 2010. Craniometric patterns of three Nigerian ethnic groups. African Journal of Biotechnology 9:1510-1513. pdf
Simpson, G.G. 1953. Major Features of Evolution. Columbia University Press, New York.
Hand-tooled boots by Tres Outlaws of El Paso, procured on eBay at a bargain:
By the way, reader John Danley asked about “the Jewish cowboy.” I have in fact actually found one: it was a picture hanging on the wall in the Eastern California Museum in the tiny town of Independence, California, between Bishop and Lone Pine. I was so taken by this that I took a photo of the photo.
Now does this look like a Jewish cowboy or what? Take a yeshiva bocher and put him in a Stetson and boots, and this is what you get. On a subsequent visit to the Museum I discovered the picture had disappeared, and I was never able to find out anything about “Hominy’s famous Jewish champion of the lariat and saddle.”
Like an old Jewish man, which is what I am, I’ll bore you with the details of my operation. Actually, there are only a few things I want to say–the main one being that it went very well and I’m back at work (against doctors’ orders, of course). I have antibiotics and pain medication, but there’s no pain so I’m eschewing the latter. Sadly, my sense of taste is temporarily impaired, but that shouldn’t last long.
First of all, a big thank-you to my surgeon, Dr. Jacquelynne Corey, who reamed out my proboscis with great finesse, and to the good-humored anesthesiologist, Dr. BobbieJean Sweitzer, who patiently explained to me the ins and outs of full anesthesia, and answered scientific questions completely irrelevant to my treatment. I am grateful to the surgery and anesthesiology residents, and the OR nurses, whose names I’ve either forgotten or did not know. Finally, kudos to Donna Morrone, RN, who kept me up to date with appointments and information.
Unfortunately, I have nothing to report about the experience of anesthesia. They zonk you out a tad with a Valium-like substance, but then the lights went out instantly. I didn’t even count backwards from 100. And it seemed that I woke up only a moment later, but actually three and a half hours had passed. There were no dreams, and I suspect—despite reports of “out of body experiences”—that dreams are less frequent under anesthesia than under regular sleep. This would, of course, say something about the brain mechanisms that get shut down during operations.
The only hitch was in intubating me, which they usually do during sinus operations. It apparently wasn’t easy. According to a letter Dr. Sweitzer gave me to pass on to future surgeons, I had a “difficult direct laryngoscopy” because of “limited mouth opening” (who would have guessed?) and “relatively large tongue.” Also, I had a “difficult tracheal intubation” because of my “short stubby epiglottis and redundant soft tissue” (that sounds like an insult—redundant tissue indeed!).
Finally, they need to do something about those hospital gowns that expose your butt! There’s just one tie in the back, and leaves little to the imagination (they gave me a blanket to drape over my back while walking to the operating room). Surely, after decades of surgery, someone can invent a better and less demeaning way to clothe a patient. If they need instant access to your back or rump, why not Velcro or snaps? If anyone knows a rationale for this, do post it below. We’d like some dignity, you know!
As for the University of Chicago Hospitals, I have nothing but praise for their treatment in this case. Everyone was friendly and eager to ensure that all my questions were answered. With luck, I’ll soon be breathing freely.
I’d like you to watch this 23-minute video to see how Islamic media deals with the Jews when it’s not even minimally constrained by having to operate within a Western country. These clips, compiled by the Middle East Media Research Institute, come from various Arab television stations. (If you can’t see the video, the link is here.)
They are sickening, especially so when children are made to parrot the hatreds of their elders. The old saw that Jews mix the blood of goyim into their Passover matzos is given big play (has anyone ever wondered why those matzos never seem to be red?), and even the Holocaust is justified with glee. Peter Singer’s expanding circle of morality seems to have missed some parts of the world.
Can anyone believe that even a two-state solution in the Middle East will quell this virulent anti-Semitism? Several announcers in fact state that wouldn’t happen. As Anthony Grayling has stressed, this is how religion behaves when it’s not on the back foot.
Presenting this stuff is not fomenting Islamophobia: it’s simply shining a light on a squalid (and not so tiny) corner of that faith that many people would prefer to ignore.
