The Unz Review - Mobile
A Collection of Interesting, Important, and Controversial Perspectives Largely Excluded from the American Mainstream Media
Email This Page to Someone

 Remember My Information



=>
Authors Filter?
Razib Khan
Nothing found
 TeasersGene Expression Blog
/
Richard Dawkins

Bookmark Toggle AllToCAdd to LibraryRemove from Library • BShow CommentNext New CommentNext New Reply
🔊 Listen RSS

Darwin One of the aspects of David Dobbs’ Aeon Magazine piece has been a significant backlash, mostly playing out on Twitter. A biologist who did quite like Dobbs’ article was P. Z. Myers. Ultimately I’m not quite sure that Myers disagrees as much with the people I follow on Twitter as you might think from the cautious and qualified tone of the endorsement, but it is clearly an endorsement (“must read today”). He observes that developmental biologists in particular might welcome Dobbs’ exposition of deviations from standard Mendelism (though this is clearly not the case for Armand Leroi, an evolutionary developmental biologist). Dobbs has clarified the thrust of his article, but the general takeaway by many was that the science has passed Richard Dawkins by, and he’s something of an old-fashioned dinosaur. That might not have been the intent, but that’s basically going to be the implication seen by a lot of non-scientists, and people outside of evolutionary biology. I know this because my whole life I’ve run into people who know the “real deal” about evolutionary biology, and aren’t shy about telling me. When I was 13 years old I remember my science teacher explaining that he didn’t buy into Darwinism. Why? Because he accepted Stephen Jay Gould’s punctuated equilibrium, which was definitely the wave of the future. Twenty years later I don’t think much has changed. Standard evolutionary biology is being modified on the margins and edges, extended and expanded, but in a gradual and incremental fashion. Gould and his acolytes are always a decade away from overturning the established order.

And speaking of Gould, here’s Paul Krugman in 1996:

I am not sure how well this is known. I have tried, in preparation for this talk, to read some evolutionary economics, and was particularly curious about what biologists people reference. What I encountered were quite a few references to Stephen Jay Gould, hardly any to other evolutionary theorists. Now it is not very hard to find out, if you spend a little while reading in evolution, that Gould is the John Kenneth Galbraith of his subject. That is, he is a wonderful writer who is bevolved by literary intellectuals and lionized by the media because he does not use algebra or difficult jargon. Unfortunately, it appears that he avoids these sins not because he has transcended his colleagues but because he does does not seem to understand what they have to say; and his own descriptions of what the field is about – not just the answers, but even the questions – are consistently misleading. His impressive literary and historical erudition makes his work seem profound to most readers, but informed readers eventually conclude that there’s no there there….

This may be harsh, but it gets to the heart of the fact that non-specialists esteem Gould far more than most working within his own purported field (I say purported, because from what I can tell Gould was a fine paleontologist. But he left much to be desired as an evolutionary theorist). An analogy with physics might be the fact that Stephen Hawking has been acclaimed as the “most brilliant mind since Einstein,” mostly due to his elegant and popular series of books for the general public. Hawking is brilliant, but he stands head and shoulders above other prominent physicists (e.g., Ed Witten) in the public mind mostly because of his popular contributions, not his scientific work. This is not necessarily a problem, except when people confuse cultural popularity with intellectual eminence.

Every decade there’s always a new trend which is gaining traction and pushing the edge in terms of what we know about evolutionary biology. In the 1970s there was molecular neutralism, which superseded tired arguments between Fisherian selectionists and Wrightian balancing serlectionists. In the 2000s you had evo-devo. Today it is epigenetics, and what that means for the “Central Dogma.” These are not crankish fads, but, the media often exaggerate the impact they’re having on a given field because that’s news. And at that point the general public gets confused as to the nature of the consensus within a field, because their perception is often filtered through the media (when it comes to cosmology, I’m the general public, so I know whereof I speak). This explains why I regularly get irritated emails and Facebook messages to the effect that my focus on population genetics is totally doing a disservice to my readership, which won’t understand that developmental biology and/or epigenetics has totally changed the game and our understanding of evolutionary genetic process.

Finally, PZ Myers seems to have sarcastically tweeted at me that we should vote on David’s piece after I wondered if any others have supported its thesis (David tells me some others have privately, and also in places like Jerry Coyne’s comment board), alluding to the reality that science isn’t a democracy, but proceeds via a method. Well, that’s the ideal. But as it is practiced science is basically the consensus of specialists. When someone plays up the existence of religious scientists PZ has no problem looking at large samples of data which suggest that conventionally orthodox religious scientists are in a small minority. Similarly, when people skeptical of anthropogenic climate change make their case, others are not shy about noting the consensus among climatologists on that question.

I can accede to the fact that within evolutionary biology the tradition which goes back to the grand triumvirate of theoretical population genetics, R. A. Fisher, Sewall Wright, and J. B. S. Haldane, is not universally accepted as having much important to say. Lynn Margulis comes to mind as someone who was skeptical of this in a vocal manner, and even the ‘orthodox,’ such as Ernst Mayr, have had their qualms with excessively formal model building. But, despite the arguments and attempts of of Margulis, Gould, and yes, Mary Jane West-Eberhard, to sideline this old orthodoxy, I believe it still remains the mainstream view of most practicing evolutionary biologists. That doesn’t mean that the classical Neo-Darwinian tradition is right, but it does mean that the scientific community probably leans toward that position more than any other alternative. And that is an important fact, because many people are confused about this, and unfortunately I’m pretty sure that David’s piece will just magnify that trend.

Addendum: Alwyn Scally suggests much of this is simply dislike of Richard Dawkins’ affect and non-scientific views on the part of those sympathetic to Dobbs’ take (though I don’t think this is David’s motivation, it may be for some of those who are taking succor from its takeaway). That is true. And how unfortunate that we sacrifice science on the alter of personal dislike.

 
• Category: Science • Tags: Richard Dawkins, Selfish Gene 
🔊 Listen RSS

There have been a variety of responses to my column in The Crux on race. To be fair, because the audience for The Crux does not consist of genome nerds I engaged in some first approximations which some readers have taken objection to. For example, the genetic architecture of blue vs. brown eye inheritance is ‘quasi-Mendelian,’ with ~75 percent of the variation in Europeans on this trait attributable to variation in the region of the HERC2 and OCA2 genes. But I thought, and still think, that a rough re-characterization of the trait as a recessive one with a monogenic Mendelian inheritance pattern can be justified for didactic purposes (just like one can justify the idea that whole human genomes have been sequenced, even if there are large gaps, and known errors in regions of repeats).

But the comments over at Richard Dawkins’ website have been rather amusing as a whole. Some people were patronizingly pedantic, and I don’t have time respond in detail (the real response would be: read my blog!). But some comments are easy to answer:

I’d like to hear Dawkins’ response to this, I’ve read all of his books and he’d surely disagree with the author of that article.

Easy. He discusses race in The Ancestors’ Tale (a book the commenter claims to have read):

The African, who was the only black person there – and he really was black, unlike many “African-Americans” – happened to be wearing a red tie. He finished his self-introduction by laughingly saying, “You can easily remember me. I am the one with the red tie.” He was genially mocking the way people bend over backwards to pretend not to notice racial differences. I think there was a Monty Python sketch along the same lines. Nevertheless, we can’t write off the genetic evidence which suggests, all appearances to the contrary, we are an usually uniform species. What is the resolution to the apparent conflict between appearance and measured reality?

It is genuinely true that, if you measure the total variation in the human species and then partition it into a between-race component and a within-race component, the between-race component is a very small fraction of the total. Most of the variation among humans can be found within races as well as between them. Only a small admixture of extra variation distinguishes races from each other. That is all correct. What is not correct is the inferene that race is therefore a meaningless concept. This point has been clearly made by the distinguished Cambridge geneticist A.W.F. Edwards in a recent paper “Human genetic diversity: Lewontin’s fallacy.” R.C. Lewontin is an equally distinguished Cambridge (Mass.) geneticist, known for the strength of his political convictions and his weakness for dragging them into science at every possibile opportunity. Lewontin’s view of race has become near-universal orthodoxy in scientific circles. He wrote, in a famous paper of 1972:

It is clear that our perception of relatively large differences between human races and subgroups, as compared to the variation within these groups, is indeed a biased perception and that, based on randomly chosen genetic differences, human races and populations are remarkably similar to each other, with the largest part by far of human variation being accounted for by the differences between individuals

This is, of course, exactly the point I accepted above, not surprisingly since what I wrote was largely based on Lewontin. But see how Lewontin goes on:

Human racial classification is of no social value and is positively destructive of social and human relations. Since such racial classification is now seen to be of virtually no genetic or taxnomic significance either, no justification can be offered for its continuance.

We can all happily agree that human racial classification is of no social value and is positively destructive of social and human relations. That is one reason why I object to ticking boxes on forms and why I object to positive discrimination in job selection. But that doesn’t mean that race is of “virtually no genetic or taxonomic significance.” This is Edwards’s point, and he reasons as follows. However small the racial partition of total variation may be, if such racial characteristics as there are highly correlated with other racial characteristics, they are by definition informative, and therefore of taxonomic significance.

One minor point: I did not notice in the original reading of this passage that Richard Dawkins comes out against what we in the USA would term affirmative action!

(Republished from Discover/GNXP by permission of author or representative)
 
• Category: Science • Tags: Race, Richard Dawkins 
🔊 Listen RSS


Hominin increase in cranial capacity, courtesy of Luke Jostins


A few years ago a statistical geneticist at Cambridge’s Sanger Institute, Luke Jostins, posted the chart above using data from fossils on cranial capacity of hominins (the human lineage). As you can see there was a gradual increase in cranial capacity until ~250,000 years before the present, and then a more rapid increase. I should also note that from what I know about the empirical data, mean human cranial capacity peaked around the Last Glacial Maximum. Our brains have been shrinking, even relative to our body sizes (we’re not as large as we were during the Ice Age). But that’s neither here nor there. In the comments Jostins observes:

The data above includes all known Homo skulls, but none of the results change if you exclude the 24 Neandertals. In fact, you see the same results if you exclude Sapiens but keep Neandertals; the trends are pan-Homo, and aren’t confined to a specific lineage….


In other words: the secular increase in cranial capacity for our lineage extends millions of years back into the past, and also shifts laterally to “side-branches” (with our specific terminal node, H. sapiens sapiens, as a reference). This is why I often contend as an aside that humanity was to some extent inevitable. By humanity I do not mean H. sapiens sapiens, the descendants of a subset of African hominins who flourished ~100,000 years before the present, but intelligent and cultural hominins who would inevitably construct a technological civilization. The parallel trends across the different distinct branches of the hominin family tree which Luke Jostins observed indicated to me that our lineage was not special, but simply first. That is, if African hominins were exterminated by aliens ~100,000 years before the present, at some point something akin to H. sapiens sapiens in creativity and rapidity of cultural production would eventually arise (in all likelihood later, but possibly earlier!).

This does not mean that I think humanity was inevitable upon earth. For most of the history of this planet life was unicellular. I do not find it implausible that life on earth may have reached its “sell by” date due to astronomical events before the emergence of complex organisms (in fact, from what I have heard the end of life is going to occur ~1 billion years into the future due to the persistent increase in the energy output of Sol, not ~4 billion years in the future when Sol turns into a red giant). But, once complex organisms arose it does seem that further complexity was inevitable. This was Richard Dawkins’ case in The Ancestor’s Tale based simply on the descriptive record. But did the emergence of complex organisms necessarily entail the evolution of a technological species? I don’t think so. It took 500 million years for that to occur (it does not seem that coal resources formed hundreds of millions of years ago were tapped before humans). Given enough time obviously a technological species would evolve (e.g., extend the time of evaluation to 1 trillion years), but note that the earth has only ~5 billion years. Homo arrived on the scene in the last 20% of that interval.

Here I am positing at a minimum two not excessively likely or inevitable events over a 5 billion year time span which would lead to a hyper-technological and cultural species:

- The emergence of multicellular life

- The emergence of a lineage with the propensities of Homo

One Homo evolved and expanded outside of Africa I suspect that something of the form of a technological civilization became inevitable n this planet. We see parallelism in our own short post-Pleistocene epoch. Multiple human societies shifted from hunter-gatherers to agriculturalists over the past 10,000 years. The experience of the New World civilizations in particular illustrates that human universal tendencies are real. Not only were “game changing” cultural forms such as agriculture and literacy invented independently during the Holocene, but they were not invented during earlier interglacials (at least in all likelihood).


Khufu, Necho, Augustus and Napoleon

Why not? Well, consider the cultural torpidity of Paleolithic toolkits, which might persist for hundreds of thousands of years! I suspect some of this due to biology. But even over the Holocene we do perceive that cultural change has proceeded at a more rapid clip as time has progressed (i.e., at a minimum cultural change has been accelerating, and it may be that the rate of acceleration itself is increasing!). Consider that the civilization of ancient Egypt spanned at least 2,000 years. Though there are clear differences, the continuity between Old Kingdom Egypt and the last dynasties before the Assyrian and Persian conquests is very obvious to us, and would be obvious to ancient Egyptians. In contrast, 2,000 years separates us from Augustan Rome. The continuities here are clear as well (e.g., the Roman alphabet), but the cultural change is also clear (if you wish to argue that the early modern and modern period are sui generis, the 1,500 year interval from Augustan Rome to the Neo-Classical Renaissance would still be a stark contrast when compared against an ancient Egyptian reference*, despite the latter’s aping of the forms of the former).

So far I have focused on the vertical dimension of time. But there is also the lateral dimension, of cross-fertilization across the branches of the hominin family tree. The admixture of a Neanderthal element into non-Africans has started to become widely accepted recently, thanks to the confluence of archaeology and genomics in the field of ancient DNA. Even if one rejects the viability of Neanderthal admixture, the solution to the conundrum of these results must still entail stepping away from a simple model of recent exclusive origin of humans from a small African population. There are also hints of admixture with other archaic lineages on the Pacific fringe, and within Africa.

Until recently it was common to posit that modern humans, our own lineage, had some special genius which allowed it to sweep the field and extinguish our cousins. The qualitative result of Luke Jostins’ plot was known; that other hominin lineages also exhibited encephalization. In fact, it was a curious fact that Neanderthals on average had larger cranial capacities than anatomically modern humans. But the reality remained that we replaced them, ergo, we must have a special genius. Until the lack of distinction between Neanderthals and modern humans on loci implicated in the necessary (if not sufficient) competency of language that trait was a prime candidate for what made “us” special. But now I put “us” in quotation marks. The data do point to an overwhelming descent from an African or near-African population for non-Africans over the past 100,000 years. But the “archaic admixture” is not trivial. What was they are us, and we have become what they might have been.

For over two centuries there has been a debate in the West between monogenesis and polygenesis. The former is the position that humankind derives from one single pair or population (the former a straightforward recapitulation of the standard Abrahamic model). The latter is the position that different races of humans derive from different proto-humans, or, for the Christian polygenists that only Europeans descent from Adam and Eve (the other races being “non-Adamic”). Echoes of this conflict persist down to the present era. Many of the earlier partisans of “Out of Africa” have claimed that the proponents of multiregionalism were latter-day polygenists (not without total justification in some cases).

But the conflict between monogenism and polygenism is not the appropriate frame for what is being unveiled by reality before our eyes. What we see in the creation of modern humanity is a monogenic base inflected with the flavors of polygenism. Modern humans descend, by and large, from an expansion of an African population over the past 200,000 years. But on the margins there are other strands and filaments of ancestry which tie disparate populations back to lineages which branched off far earlier from the main trunk. At a minimum hundreds of thousands, and perhaps an order of 1 million years, before our own age. Today genomics avails of us the statistical power to extract out these discordant signals from the fluid “Out of Africa” narrative, but I would not be surprised if in the near future we stumble upon more and more “long branches” of less noteworthy quantity. Admixture is likely to be an old and persistent story in the hominin lineage, with only the most recent substantial bouts of separation and hybridization being of notice and curiosity at this moment in time.

What does all this mean? And why have I juxtaposed deep time natural history across the tree of life with inferences of relatively recent paleoanthropology? Let’s start with two propositions:

- Technological civilization, an outward manifestation of radically complex sentience, is not inevitable, though it is probable given certain preconditions (I believe that the existence of Homo increased its probability to ~1.0 over a reasonable time period)

- Radically complex sentience is not the monopoly of a particular exclusive lineage which accrues its genius from a particular specific forebear

John Farrell has pointed out the possible issues that the Roman Catholic church may have with the new model of human origins. But the Catholic church is only but a reflection of more general human strain of thought. Descent-groups, whether real or fictive, loom large in the human imagination. The evolutionary rationale for this is not too hard to explain, but we co-opt the importance of kinship in many different domains. Like evolution, human cultural forms simply take what is already present, and retrofit and modify elements to taste.

So why are humans special? And why do humans have inalienable rights? Many of us may not agree with the proposition that we are the descendants of Adam and Eve, and therefore we were granted the divine grace of eternal souls. But a hint of this logic can be found in the assumptions of many thinkers who do not agree with the propositions of the Roman Catholic church. Recently I listened to Sherry Turkle arguing against a reliance on “robot companions” which are able to exhibit the verisimilitude of human emotions for those who may be lacking in companionship (e.g., the aged and infirm). Though Turkles’ arguments were not without foundation, some of her arguments were of the form that “they are not us, they are not real, we are real. And that matters.” This is certainly true now, but will it always be? Who is this “they” and this “we”? And what does “real” mean? Are emotions a mysterious human quality, which will remain outside of the grasp of those who do not descend from Adam, literal or metaphorical?

If there arises a point where non-human sentience is a reality, do they have the same rights as we? Though the difference is radical in terms of quantity to some extent I think we know the answer: they are human by the way they are, not by the way their ancestors were. The “taint” of admixture with diverse lineages across the present human tree of life has not resulted in an updating of our understanding of human rights. That is because the idea that we are all the children of Adam, or the descendants of mitochondrial Eve, is a post facto justification for our understanding of what the rights of humanity are, adn what humanity is. And what it is is a particular ecological niche, a way of being, not being who descend down in a line of biological relationship from a particular person or persons.

* The cultural fundamentals of Old Kingdom Egypt arguably persisted in a living fossil form in the temple at Philae down to the 6th century A.D.! Therefore, a 3,500 year lineage of literature continuity.

Image credits: all public domain images from Wikpedia

(Republished from Discover/GNXP by permission of author or representative)
 
No Items Found
Razib Khan
About Razib Khan

"I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. If you want to know more, see the links at http://www.razib.com"