Ancient migrations in Southeast Asia: The past movements and peopling of Southeast Asia have been poorly represented in ancient DNA studies (see the Perspective by Bellwood). Lipson et al. generated sequences from people inhabiting Southeast Asia from about 1700 to 4100 years ago. Screening of more than a hundred individuals from five sites yielded ancient DNA from 18 individuals. Comparisons with present-day populations suggest two waves of mixing between resident populations. The first mix was between local hunter-gatherers and incoming farmers associated with the Neolithic spreading from South China. A second event resulted in an additional pulse of genetic material from China to Southeast Asia associated with a Bronze Age migration. McColl et al. sequenced 26 ancient genomes from Southeast Asia and Japan spanning from the late Neolithic to the Iron Age. They found that present-day populations are the result of mixing among four ancient populations, including multiple waves of genetic material from more northern East Asian populations. Science , this issue p. 92 , p. 88 ; see also p. 31

Anatomically modern humans reached East Asia more than 40,000 years ago. However, key questions still remain unanswered with regard to the route(s) and the number of wave(s) in the dispersal into East Eurasia. Ancient genomes at the edge of the region may elucidate a more detailed picture of the peopling of East Eurasia. Here, we analyze the whole-genome sequence of a 2,500-year-old individual (IK002) from the main-island of Japan that is characterized with a typical Jomon culture. The phylogenetic analyses support multiple waves of migration, with IK002 forming a basal lineage to the East and Northeast Asian genomes examined, likely representing some of the earliest-wave migrants who went north from Southeast Asia to East Asia. Furthermore, IK002 shows strong genetic affinity with the indigenous Taiwan aborigines, which may support a coastal route of the Jomon-ancestry migration. This study highlights the power of ancient genomics to provide new insights into the complex history of human migration into East Eurasia.

Grammar can reflect genetic history better than other cultural traits, including the lexicon.

The molecular mechanisms of the endogenous circadian clocks that allow most animals to adapt to environmental cycles have recently been uncovered. The draft genome of the ascidian, Ciona intestinalis, a model animal that is close to vertebrates, has been described. However, the C. intestinalis genome lacks the canonical clock genes such as Per, Bmal and Clock that are shared by vertebrates and insects. Here, we found the circadian rhythms at the physiological and molecular levels. The oxygen consumption rate was lower during the light phase and higher during the dark phase during a day, and the rhythm highly damped and continued under constant darkness. From the microarray analysis, the 396 spots (1.8% of the total; corresponding to 388 clones) were extracted as candidates for circadian expression. We confirmed the circadian expression of several candidate genes by northern blotting. Furthermore, three of four rhythmic expressed genes showed phase-shifts to prolonged light period. However, most of known clock genes did not oscillate. These data suggest that C. intestinalis have a unique molecular circadian clock and the daily environmental change is not such a strong effect for sea squirt in its evolution when compared to vertebrates and insects.

The lifestyles of the order Geoglossales (Geoglossomycetes, Ascomycota) remain largely unknown. Recent observations support ericoid mycorrhizal lifestyles, especially in cultured Sarcoleotia-related species. However, the currently known genomes of geoglossoid fungi encode fewer carbohydrate-active enzymes (CAZymes) in Pezizomycotina, in contrast to the abundant CAZyme repertoires found in well-known ericoid mycorrhizal fungi. The absence of assembled genomes for cultured geoglossoid fungi hinders our understanding of the genomic features related to their lifestyles. We hypothesize that the genome of Sarcoleotia globosa, a putative ericoid mycorrhizal fungus, encodes abundant CAZymes, consistent with its culturability. General features, such as smaller genome size and smaller number of genes, are shared between the genome of S. globosa strain NBRC 116039 and other geoglossalean genomes. However, the former had the most extensive CAZyme repertoire, with several enzyme families involved in plant cell wall degradation. Some of these CAZymes are not found in Geoglossales and closely related lineages. Nonetheless, the number of CAZymes from S. globosa was notably smaller than that previously reported in ericoid mycorrhizal fungi. This inconsistency may highlight not only ecophysiological variation among ericoid root mycobionts but also the specific evolution of lifestyles in Geoglossales.