Research Update TRENDS in Ecology & Evolution Vol.17 No.7 July 2002 301

Meeting Report Joining forces to uncover human evolutionary history Noah A. Rosenberg and

A meeting on Genes, Peoples and assimilation in Africa could have caused (Stanford University) described a novel Languages, in honor of the 80th birthday linguistic extinctions without purging approach to measuring distances of L. Luca Cavalli-Sforza, was held at the genetic variability, whereas geographical between phylogenetic trees; one of us Institute for Pure and Applied Mathematics, fragmentation in the Americas might (N.A.R.) discussed that the time to the University of California, Los Angeles, have led to linguistic expansions in a most recent common ancestor of a genetic CA, USA, from 11 to 15 February 2002. group that was genetically relatively sample is only weakly related to the homogeneous [6]. separation time of two populations Published online: 07 May 2002 from which the sample was taken; and archaeology Robert Martin (Field Museum of Natural The discovery of blood-group The interdisciplinary exchange at the History, Chicago, IL, USA) showed that polymorphisms in the early 1900s meeting highlighted the benefits of the most ancient fossil from a group can provided the first anthropological markers communication between geneticists and be considerably more recent than the that were easily measured, genetically anthropologists. As data accumulate, origin of the group itself. For the simple and constant throughout geneticists can develop ever more primates, this gap might be tens of individual lifetimes. Moreover, they had sophisticated models, constrained by millions of years [8]. multiple frequent types, most of which archaeological results on population-size had worldwide distributions, but whose fluctuations and spatiotemporal locations The importance of multiple markers frequencies differed among human of ancient peoples. Joanna Mountain’s A key insight from the coalescent populations [1,2]. Could it be possible to (Stanford University) work with approach is that multilocus data are infer the history of human migrations Alec Knight demonstrated the utility of needed for comparing likelihoods of using this genetic variation, and that of informed interdisciplinary dialogue: her demographic scenarios. More generally, the new markers that were continually description of extreme genetic distances Marta Mirazón Lahr (Cambridge being identified? Geneticist L. Luca between click-speaking Hadzabe of University, UK) pointed out that signals Cavalli-Sforza (Stanford University, Tanzania and speakers of click languages of different characters dissipate at Stanford, CA, USA) answered ‘yes,’ in southwest Africa revives a hypothesis varying rates, with linguistic change integrating genetics with knowledge that clicks might have been part of a being most rapid, genetic change about climate, culture, geography, language spoken by a population somewhat slower, and change of major language and skeletal morphology [3]. ancestral to all extant humans. ‘morphological complexes’ even slower. With the inherent difficulty in Analysis of complex genetic models Thus, studies of events on a particular reconciling these diverse sources of data, requires assistance from mathematics timescale should use markers that would reconstructing what actually happened and computational statistics. have evolved on that scale. For example, in recent remains a Henry Harpending (, Jean-Jacques Hublin (Université challenge. The Institute for Pure and Salt Lake City, UT, USA), Bordeaux, France) and Alan Walker Applied Mathematics (IPAM) meeting Magnus Nordborg (University of Southern (Pennsylvania State University, was designed to foster discussion among California, Los Angeles, CA, USA), and University Park, PA, USA) showed that the several research communities Charles Oxnard (University of Western slowly changing allometric relationships interested in this same endeavor. Australia, Perth, Australia) showed how that vary relatively little within groups Cavalli-Sforza’s wide-ranging keynote simulation of diverse scenarios consistent are appropriate for comparisons of fossils. address included a retrospective on with known human history can be Walker found that slower rates of dental his famous comparison of genes and accomplished. However, the more difficult development, which correlate with languages, which found that trees of problem of statistical inference about extended life histories, might reflect the human populations and trees of what actually did happen is another cognitive breakthroughs of modern languages can be surprisingly concordant matter. Because individual genomes humans; interestingly, the dental [4,5]. One of us (D.N.) noted that, are related through genealogical trees development pattern of modern humans although genetic variation might be that arose during the stochastic process was shared by a Neanderthal but not largest among Africans, the Americas, of evolution, genotypes of different by apes, Australopiths, or other species which have less genetic diversity, contain individuals are inherently correlated, of the genus Homo [9]. many more language families. This producing data that is not suited to The meeting provided a glimpse apparent anomaly arises from the fact standard statistical approaches. Thus, into issues that are imminent with that genes and languages provide coalescent theory, specially designed for the forthcoming glut of human different information about the past, as a such data, will acquire a greater role [7]. genomic polymorphism data. Daniel result of the different forces that operate Numerous subtleties in evolutionary Falush (Max Planck Institute, Berlin, on them. For example, recent cultural data were presented: Susan Holmes Germany) presented a new algorithm

http://tree.trends.com 0169-5347/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII: S0169-5347(02)02506-5 302 Research Update TRENDS in Ecology & Evolution Vol.17 No.7 July 2002 for inference of population relationships linking of genomic and anthropological 5 Cavalli-Sforza, L.L. et al. (1992) of using data from many loci, data, as proposed by Cavalli-Sforza, is genes and languages revisited. Proc. Natl. Acad. Sci. U. S. A. 89, 5620–5624 demonstrating the method on the human sure to provide years of exciting work 6 Nettle, D. (1999). Linguistic diversity of the parasite Helicobacter pylori, for which for us all. Americas can be reconciled with a recent suitable data are already available. colonization. Proc. Natl. Acad. Sci. U. S. A. Multilocus studies of human populations Acknowledgments 96, 3325–3329 presented by Anna Di Rienzo and We thank the staff at the Institute for 7 Nordborg, M. (2001) Coalescent theory. In Handbook of Statistical Genetics (Balding, D.J. Wen-Hsiung Li (both from the Pure and Applied Mathematics and the et al., eds), pp. 179–212, John Wiley & Sons University of Chicago), as well as primate organizers for a successful meeting. 8 Tavaré, S. et al. Estimating the age of the last microarray comparisons discussed by Abstracts and presentations from common ancestor of extant primates using the Joseph Hacia (University of Southern the meeting are available at fossil record. Nature (in press) California), suggest that we might soon http://www.ipam.ucla.edu. 9 Dean, C. et al (2001) Growth processes in teeth distinguish modern humans from Homo erectus be able to identify the loci that have and earlier hominids. Nature 414, 628–631 undergone selection during the history References of the human lineage. Whereas neutral 1 Hirschfeld, L. and Hirschfeld, H. (1919) loci can be used to help reconstruct Serological differences between the blood of Noah A. Rosenberg* different races. The result of researches on the demographic histories, selected genes, Molecular and Computational Biology, Macedonian front. Lancet 197(ii), 675–679 together with temporal changes in 2 Mourant, A.E. (1954) The Distribution of the University of Southern California, morphology and behavior, can help Human Blood Groups, Blackwell Scientific Los Angeles, CA 90089, USA. determine what characters led to 3 Cavalli-Sforza, L.L. et al. (1994) The History *e-mail: [email protected] proliferation of anatomically modern and Geography of Human Genes, Princeton humans. Whether Richard Klein’s University Press Daniel Nettle 4 Cavalli-Sforza, L.L. et al. (1988) Reconstruction of (Stanford University) scenario of a rapid human evolution: bringing together genetic, Depts of Psychology and Biological Sciences, positively selected genetic change archaeological, and linguistic data. Proc. Natl. Open University, Milton Keynes, ~50 000 years ago is supported, the Acad. Sci. U. S. A. 85, 6002–6006 UK MK7 6AA.

Birds of two worlds: temperate–tropical migration systems Robert E. Ricklefs

The Birds of Two Worlds symposium was that migratory behavior is extremely (D.E. Irwin and J.H. Irwin, Lund held at the US Fish and Wildlife Service’s labile (A. Helbig, University of Greifswald, University, Sweden). Such divides, National Conservation Training Center, Germany; L. Joseph, Philadelphia associated for example with routes to Shepherdstown, WV,USA, from Academy of Natural Sciences, PA, USA) the east and west of the Himalayan 6 to 10 March 2002. with losses exceeding gains in North Mountains, often coincide with species American warblers by 15 to 2 transitions boundaries. Sister-taxon relationships Published online: 07 May 2002 (I. Lovette, Cornell University, NY, USA). in clades with migrants nonetheless Migrating species or clades of songbirds tend to follow north–south axes between Each spring, billions of birds begin their have their ancestral roots predominantly migrants and nonmigrants, rather northward migration to summer breeding in tropical rather than temperate than east–west axes between migrant grounds. Recently, 150 biologists residents. In several groups, some populations. converged somewhat ahead of the spring nonmigratory species are derived from Ecological relationships of long- migrants to discuss the ecology and populations of migrants that remained in distance migrants differ dramatically evolution of these migration systems. their winter quarters to form isolated between North America, where most The topics at this symposium ranged breeding populations in the West Indies, species spend the winter in forested from the evolution of migration to southern Europe, the Indian Ocean regions of the wet tropics, and the adaptations of migrants to their summer and Australasia. Western Palearctic, where destinations and winter environments, constraints Postnatal dispersal by migrants tends are primarily the drier, savanna and imposed on annual cycles by migration, to homogenize genetic variation within woodland habitats of tropical Africa and genetic and geochemical markers populations, seemingly reducing the (P. Hockey, University of Cape Town, used to localize the origins of migrant potential of migrant species to diversify South Africa; K. Böhning-Gaese, individuals. Recent findings based on (D. Winkler, Cornell University). On a Universität Mainz, Germany; F. Bairlein, new technologies complemented the larger scale, however, migration divides Institut für Vogelforschung, Germany). deepening insights into ecology and between adjacent breeding populations The habitat differences among winter behavior developed through more that take alternative migration routes to migrants are paralleled in some cases traditional approaches. disjunct wintering areas strongly inhibit by habitat preferences on the breeding Character mapping of migration on mixing owing to the low fitness of hybrids grounds (T. Price, UC San Diego, CA, molecular phylogenetic trees indicates that set off on inappropriate headings USA), and also appear to influence social

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