An analysis of ancient human DNA from central Africa is presented in Nature this week, shedding new light on African population history. A Harvard University-led team analyzed genome-wide DNA data from four children buried in Cameroon approximately 3,000 and 8,000 years ago. They find that these individuals' ancestry profiles are most similar to those of present-day hunter-gatherers from western Central Africa, which implies that populations in western Cameroon today — including speakers of Bantu languages from across the continent — are not descended substantially from the population represented by the four people. The researchers also identify evidence of widespread admixture and three prominent radiations, including one that gave rise to at least four major lineages deep in the history of modern humans. GenomeWeb has more on this, here.
By combining amplicon and metagenomic sequencing techniques with culture-enriched molecular profiling, investigators from the University of Calgary and their collaborators developed an approach for studying the human microbiota. As reported in Nature Microbiology, the research group applied their method to cystic fibrosis lung microbiota, culturing an average of 82.1 percent of the operational taxonomic units representing 99.3 percent of the relative abundance identified in direct sequencing of sputum samples. Notably, culture enrichment uncovered 63.3 percent more operational taxonomic units than direct sequencing. The scientists also developed an algorithm to determine a representative subset of culture plates on which to conduct culture-enriched metagenomics, resulting in the recovery of greater taxonomic diversity with better metagenome-assembled genomes, longer contigs, and better functional annotations when compared to culture-independent methods.