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Robson-Brown, K.

Publications and source records attributed to Robson-Brown, K..

2 recordsLinked to original sources

The genetic origins of Saint Helena’s liberated Africans

Between the early 16th and late 19th centuries, an estimated 12 million Africans were transported to the Americas as part of the transatlantic slave trade. Following Britains abolition of slave trade in 1807, the Royal Navy patrolled the Atlantic and intercepted slave ships that continued to operate. During this period, the island of St Helena in the middle of the South Atlantic served as a depot for \"liberated\" Africans. Between 1840 and 1867, approximately 27,000 Africans were disembarked on the island. To investigate their origins, we generated genome-wide ancient DNA data for 20 individuals recovered from St Helena. The genetic data indicate that they came from West Central Africa, possibly the area of present-day Gabon and Angola. The data further suggest that they did not belong to a single population, confirming historical reports of cultural heterogeneity among the islands African community. Our results shed new light on the origins of enslaved Africans during the final stages of the slave trade and illustrate how genetic data can be used to complement and validate existing historical sources.

genomics

Reptile-like physiology in Early Jurassic stem-mammals

There is uncertainty regarding the timing and fossil species in which mammalian endothermy arose, with few studies of stem-mammals on key aspects of endothermy such as basal or maximum metabolic rates, or placing them in the context of living vertebrate metabolic ranges. Synchrotron X-ray imaging of incremental tooth cementum shows two Early Jurassic stem-mammals, Morganucodon and Kuehneotherium, had lifespans (a basal metabolic rate proxy) considerably longer than comparably sized living mammals, but similar to reptiles, and that Morganucodon had femoral blood flow rates (a maximum metabolic rate proxy) intermediate between living mammals and reptiles. This shows maximum metabolic rates increased evolutionarily before basal rates, and that contrary to previous suggestions of a Triassic origin, Early Jurassic stem-mammals lacked the endothermic metabolism of living mammals.One Sentence Summary Surprisingly long lifespans and low femoral blood flow suggest reptile-like physiology in key Early Jurassic stem-mammals.View Full Text

paleontology