Fighting the Neandertal blahs05 Jan 2009
I’m worried about Neandertals. Not their bones, so much. Mainly their future.
We’re living in a culture with Neandertal sitcoms and talk of cloning Neandertals from chimpanzee oocytes. The Renaissance brought back the ideas of classical Rome and Greece. Our age seems bent on bringing back the Mousterian.
But whether it’s oversaturation or undercontextualization, certain Neandertal news is slipping through the cracks.
Last week, Carles Lalueza-Fox and colleagues reported that the Neandertals of El Sidron had blood type O. That’s pretty interesting. Heck, five years ago it would have been big exciting news. Three years ago, a partial protein sequence from Neandertal bones was fairly big news, even though the sequence was identical to humans and had no new information.
This week, blood type O in Neandertals barely merited a mention in a single news story, which mainly focused on last year’s news about MC1R and FoxP2 sequences in the same fossils.
Five years ago, finding blood type O in Neandertals would have been a Ph.D. project. Today, it’s a short paper in BMC Evolutionary Biology. I applaud the authors for choosing the open source outlet, and getting the result out there rapidly. It’s solid work. It just seems to have gotten easier.
Raw data about Neandertal genetics are quickly losing their novelty. Next year, with some luck we’ll have a draft genome, no doubt reporting a lot more about Neandertal phenotypes. That will be big news. But will any other future sequencing effort be given as much attention or importance?
And will the next “next-generation” sequencing method make it easier to get ancient DNA sequences? The reads of 20 bp and less from the 454 method have allowed a huge breakthrough. But the longer read lengths from newer technologies don’t seem as good a match to ancient DNA samples, where the original sequence is broken into very short fragments.
There may be a problem brewing here.
Neandertal genetic information is gaining more and more scientific value. Once we have a workable genome, we will be able to answer questions about Neandertal population demography and adaptation that would have simply been impossible before. This has the potential of creating a new frontier in paleoanthropology – but only if the science can be replicated in many individuals. Many of the interesting hypotheses can be tested only by considering variation among many individuals. Every sequence must be obtained with the same care and attention, because when the data are necessarily sparse, a single outlier can exert a large influence on outcomes.
Sequencing a single Neandertal is a challenging task requiring the attention of many people. Some parts of the process have been automated, or at least standardized, but it takes a lot of tweaking, hands-on knowledge, and dedicated experience to yield results that anyone can trust. In the near future, we are going to need many specialists competent to shepherd Neandertal genetic results from bone to database. We are going to need lots of attention on this issue so that we can find ways to guarantee access, protect data from loss, and preserve precious specimens.
I’m a little worried that the topic may be poised to lose attention just at the moment that it should receive more intensive effort. What incentives will there be to generate data from Neandertals?
Today, we enjoy open access to genetic data from Neandertal specimens after they have been reported – a wonderful situation compared to other kinds of data in paleoanthropology. But that policy is the product of a unique ecology – one in which data are continually easier to obtain and replicate, and in which each technical advance gives a great payoff in terms of publications and attention.
Will the ecology continue? I don’t have an answer. The current players in Neandertal genetics have done a wonderful job, and have advanced the ecosystem in a way that allows outside analysts – like me – to do good work.
But more than anything, I’m concerned that the sequencing technology will move away from methods that make ancient DNA easier and easier to obtain. For the past several years, ancient DNA and human genetics methods have moved in parallel. Neandertal genetics has benefited greatly from technologies that have been widely applied for humans and other organisms. But if these methods diverge, it may create a real bottleneck in terms of skillsets and methods for obtaining new data from Neandertal specimens.
Lalueza-Fox C. Gigli E, de la Rasilla M, Fortea J, Rosas A, Bertranpetit J, Krause J. 2008. Genetic characterization of the ABO blood group in Neandertals. BMC Evol Biol 8:342. doi:10.1186/1471-2148-8-342