There’s a rather boring but predictable complaint in The Washington Post, In the land of make-believe, racial diversity is a fantasy. We’ve been here before. The author of The Washington Post piece seems angry that his black child can’t identify with the white characters that dominate in fantasy films. But what this has to do with fantasy, as opposed to films, I don’t understand. The visual media aims toward the biggest American (and now Chinese) audience, and is averse to diversity because it thinks it doesn’t pay. I don’t know if Hollywood’s estimation is right or not, but it is no surprise that they turned the Filipino Juan Rico of Robert Heinlein’s Starship Troopers into a Nordic superman archetype Johnny Rico in the movie (granted, this was partly a function of Paul Verhoeven’s “artistic vision”).

While fantasy fiction tends toward a Northern European setting because of the influence of J. R. R. Tolkien, you can find a fair number of works which don’t fit this well-worn template.* Recently David Anthony Durham in his Acacia series of books has crafted a world where people of African-like features are prominent. The plot lines exhibit some aspect of symbolic inversion in terms of the conventional racial framework which we see so prominently in the world of Tolkien, where European-like peoples contribute the protagonists and assorted colored peoples are easily swayed to the side of the dark lord (the historical origins of this are explored in The Silmarillion). In Acacia the antagonists are the people of the north, though in the end amity is achieved.

Of course you don’t need to even look that hard to find something with breaks the mould, Ursula K. Le Guin’s Wizard of Earthsea series consciously inverts conventional racial motifs. The civilized people of the world are dark skinned, while the barbarians are clearly substitutes for Europeans. I find Le Guin’s tendency to be rather explicit with what she’s doing in terms of inversion as a “teachable moment” rather ham-handed when it comes to how the ideology interleaves with the plotting.  It occupies the foreground a bit too much for my taste. But she’s an acclaimed stylist and world-builder for a reason (I like to think of her as Jerry Pournelle’s mirror image, though his strength is more in world-building than prose style). It also has the virtue of being relatively friendly to children in comparison to Acacia, which is clearly part of the boom of more realistic novels which were published in the wake of A Song of Ice and Fire.

Finally, I need to mention Judith Tarr’s Avaryan Rising series. I won’t describe it in too much detail, but despite the illustration on the cover there really are no white European-like protagonists in the whole series, first to last.  But the peoples depicted in these novels are far more exotic than those in either Le Guin or Durham’s universes, and it is somewhat difficult to find easy cognates for them in our world. At the end of the arc of books Tarr actually anchored her Avaryan novels back to our universe. I wonder if that was partly because her own creation in a standalone sense was too exotic to be a plausible secondary world for too many.

The concept of a secondary world is simple. It’s basically the setting for a fantasy novel, and is usually apart, and somewhat different in its basic rules from our own universe. Middle Earth is a classic case. The world of Song of Ice and Fire is another. But one thing about secondary worlds is that our ability to immerse ourselves within them seems to be optimal when they exhibit a fine balance between the lushly alien and the prosaically familiar. This is why this passage from The Washington Post piece is ridiculous:

…Why couldn’t the main characters in these films have been a panoply of diversity? The beauty and ease of diversity in fantasy is that it requires no explanation. It’s fantasy, after all. Just as you don’t have to provide a metaphysical explanation for the existence of a talking snowman, neither would you need to explain why one sister in “Frozen” was Latina, the other white and their dead mother Asian. A fantasy world just is. The strength of the story is all that matters.

No, the strength of the story is not all that matters. World-building is critical, and that needs coherency and clarity. Fantasy is not the same as magical realism. As I note above the most successful fantasy series tend to be those embedded within a backdrop with definite allusions to the lineaments of our world in its order and structure. Tolkien’s world-building was strongly derivative of our own, as is Martin’s. The human imagination has limits, and the reality is that most fantasy authors simply rearrange the cognitive furniture which we find familiar in a plausible but mildly exotic manner. Some barely make a pretense at hiding the origins of their secondary world as a shadow of our own. Kate Elliott’s Crown of Stars series which began with King’s Dragon is based upon 10th century Europe, with a focus upon Ottonian Saxony. She even creates social-cultural analogs to the Christian church, Islam, as well as historical events and personages such as the Byzantine princess Theophanu.

The key in a plausible secondary world is that the familiar is turned interestingly alien, but not too much. Elliott’s very familiar world has elves and assorted supernatural entities. In addition, the relations between men and women are much more egalitarian and complementary than they were in the real 10th century (the clerical elite of the quasi-Christian religion are generally women). This points to the reality that fantasy in literary form can be quite diverse in the way that it modulates and inflects its source material toward the unfamiliar or strange. The author Ricardo Pinto created a very exotic world which is hard to place in relation to our own in his novel The Chosen, but he specifically included a strong gay theme through the series. If you want something with a Christian tinge, Stephen R. Lawhead is there for you. And so on. Strange as it may seem, the best speculative fiction probably consists of minimally counter-intuitive ideas peppered through a conventional setting and story. That is why stories which are exclusively about non-humanoid species, such as in John Brunner’s The Crucible of Time, are not very common. And it is probably why a hard science fiction author prone to extruding very startling futures such as Greg Egan is often acclaimed, but is unlikely to become a bestselling author.

The subtle balance between these variables which lend exoticism and plausibility is why “race blind casting” in fantasy novels is probably not feasible. There are plenty of series with characters of different races playing leading roles, but because they are often pre-industrial secondary worlds all the individuals have to have their own ethnic back-story. It has to make sense in some way that is plausible to us as we understand the pre-industrial world to be. The fact is that it seems likely our native “folk taxonomy” is such that most people would find a “white” mother and father with a biological “Asian” child in a secondary world is ridiculous without some explanation. Fantasy can only be so ridiculous before it loses it allure.

* You might find this Brandon Sanderson piece about the downsides of Tolkien looming so large in modern fantasy interesting.

Note: I’d like to note that the correspondence of secondary worlds to our world holds for Saladin Ahmed’s Throne of the Crescent Moon. It’s vaguely set in an Abbasid-like world.

The above figure is from a preprint, Recent evolution of the mutation rate and spectrum in Europeans, which reports very peculiar results from the 1000 Genomes data. I actually got a preview of the topline finding about a year and a half ago at a Bay Area Population Genomics meeting, but many of the details are new to me. As noted in the abstract the “private European variation is enriched for the transition 5’-TCC-3’→5’-TTC-3’.” The implication here is that different populations mutate differently. The preprint puts this in the broader context of the fact that for a while now there have been conflicts between different rates of mutation inferred from pedigree and whole genome sequencing, and phylogenetic models of divergence of species. At this point the technical details need not concern. Rather, let’s just add that the recent ancient Siberian genome paper confirmed this discrepancy, and strongly supports the contention within this preprint that the mutational rates across the ape lineages are likely to have varied, questioning the validity of an invariant molecular clock.

Frankly I trust Harris to be right about the pattern she sees here. She’s been looking at this data for a few years, so if there was any statistical artifact here I am confident either she or her advisers or colleagues would have caught it. But there are some issues with the attempt to integrate these results about differences in mutational spectrum with population history. Some of these are pointed out in the comments at bioRxiv. Aside from the simple semantic conflation of Early European Farmer (EEF) for Eastern European Farmer, the attempt to suggest that reduced enrichment in northern Europe is a function of Ancestral North Eurasian (ANE) admixture is made less persuasive by pointing to the case of Finns, who are known to have a secondary East Asian admixture which arrived from Siberia more recently. I think that this is not a problem when you see another issue “Because East Asians share a more recent common ancestor with ANE than with west Eurasians.” I do not think this is the dominant view. Rather, ANE and West Eurasians are best modeled as a distinct clade with deep common ancestry as against East Eurasians. See figure 3 of Lazaridis et al. The confusion here matters because the thesis being presented seems to be that ANE lacked the enrichment of a particular mutational class, as modern East Asians do. This is a warranted conjecture if the two formed a clade with West Eurasians as an outgroup, but this is just not the case.

Which brings us to when and why the ancestors of Europeans began to exhibit this particular mutational pattern. As it happens the results show that even without the Finnish sample there is a north-south gradient of enrichment toward the latter. This would support a model where ANE admixture resulted a decrease from an originally higher proportion. That would mean then that the change occurred probably in the interval of 20 to 30 thousand years ago, when we presume the ancestors of West Eurasians and Ancestral North Eurasians diverged. But this is not the only option. One element of EFF ancestry is Basal Eurasian, which happens to be a group which is equally distant from West Eurasians, ANE, and East Eurasians. In other words, Basal Eurasians possibly diverged from all these populations before the primary Out of Africa event ~60 thousand years ago. If the mutational spectrum deviation derives from Basal Eurasians then the gradient could be a function of reduced EEF ancestry in Europe as one goes north. Looking at the difference between the Finnish and Italian samples I do not think this is the case, the variation is too small. The EEF fraction varies a great deal in Europe. So the ANE dilution model actually does seem more plausible.

But there’s a final element to be explored. Why is there in enrichment in the first place? It turns out that this sort of mutation is very common in melanomas. In particular of interest to me: “Folate deficiency is known to cause DNA damage including uracil
misincorporation and double-strand breaks, leading in some cases to birth defects and reduced male fertility.” Folate deficiency can occur when light skinned individuals are exposed to sunlight. It strikes me that the higher mutational load for these particular transitions in Southern Europeans as opposed to Northern Europeans could simply be a function of the fact that they are in sunnier climates. We know that Europeans have become much lighter skinned very recently, so the range of mutations we are seeing may be due to very recent factors. No one knows concretely why Europeans became very light skinned very recently, but these mutations may simply be a side effect of this phenotypic change, which was driven by powerful selective forces.

Citation: Recent evolution of the mutation rate and spectrum in Europeans, Kelley Harris, http://dx.doi.org/10.1101/010314

Addendum: It would have been nice of the 1000 Genomes had at least one Middle Eastern population.

Simon Gravel has a new preprint up on bioRxiv, When is selection effective? It’s a preprint, so has to be thought of as a work-in-progress. From my perspective it’s interesting because it combines analytic methods along with simulation in an attempt to sharpen intuitions about the power of selection to modulate genetic load. Issues relating to load matters because there have been empirical results and arguments about the differences between human populations due to findings from genomics over the past 10 years (e.g., Europeans have higher load than Africans because of lower long term effective population size). More generally I believe that the interplay of selection and drift across natural history are relevant for conservative genetics.

These results seem to imply that using realistic models of human demographic over the past ~100,000 the differences in load should be relatively minor. Interestingly the power of selection on recessive alleles of large deleterious effect actually becomes stronger in bottlenecked populations, presumably because of exposure of homozygotes. This is obvious in hindsight. In contrast weakly deleterious alleles are more efficiently purged in the larger effective population size of Africans.

The main thing I took away from the preprint is the emphasis on the long term population history and its impact on genetic load in a given generation. It strike me that this is why simulation methods are so persuasive, as the combined effects are indeed subtle.

Citation: When is selection effective?, Simon Gravel, http://dx.doi.org/10.1101/010934

A few weeks ago I went hiking around Lake Tahoe, and at a local coffee shop I couldn’t help overhearing a bunch of middle-aged women enthusing wildly about a new service which matches you up with someone based on your genetic profiles. They noticed my gawking and so I stopped listening, but honestly I was somewhat worried that they were so credulous. A Slate piece, Online dating sites use DNA to make perfect matches. Does it really work?, hits most of the major issues that I have with these services. As noted in the Slate review the various results attempting to correlate MHC profiles with attraction have been mixed at best (i.e., they don’t seem particularly robust). But the bigger issue to me is that even if there is a modest population-wide effect which has an underlying evolutionary basis, it is unlikely to be one of the parameters impacting relationship success. What I mean is that even if immune profile matching (or lack thereof) matters, it matters far less than other variables which are much more visible and obvious. For example, physical attraction and cultural compatibility.

Genetics is real. It’s powerful. It matters. And that means all sorts of snake-oil salesmen will start to enter the field to make money. No surprise. The reality is that for most things that matter you already know the likely genetic outcome. Look at the parents.

Daylight savings time. Sleeping in!

Nearly done with Toby Wilkinson’s The Rise and Fall of Ancient Egypt, and very much enjoyed it. I’m a big fan of scholarly surveys which can fill in my picture of the past. To be honest the most I’ve read about ancient Egypt since I was a child is probably in works such as A History of the Ancient Near East ca. 3000 – 323 BC or the fascinating Brotherhood of Kings: How International Relations Shaped the Ancient Near East. It strikes me as pretty important to get a better understanding and mental picture of a society whose framework serves as an unstated backdrop to much of our understanding of early human history.

The only issue I might take with Wilkinson’s treatment is that it leans a bit too much toward narrative diplomatic history, as opposed to the social and cultural texture of ancient Egypt. Then again, emphasizing battles and pharaohs probably makes it much more readable for most of the audience, and perhaps it says something that this is the first full length history of ancient Egypt I’ve read front to back in in nearly two decades.