Bioscience

Breakthrough in Research on Human Genetic Mechanism

To reveal the myth of phenotypic diversity of the human being, doctoral student Wu Dongdong and his tutor Zhang Yaping, member of CAS, from the Kunming Institute of Zoology, CAS systemically analyzed the population polymorphism of skeletal genes and compared them with other genes in the genome. They found that the SNP site in skeletal genes exhibits a significantly greater level of population differentiation between Africans and non-Africans (Europeans and East Asians). It’s worth noting that this character is more evident in non-synonymous substitution mutation that may affect the function of genes, but it is not shown in Europeans and East Asians. It is interesting that SNPs with higher levels of differentiation have correspondingly higher derived allele frequencies in Europeans and East Asians, which, however, is not shown in Africans. Their research indicated that positive selection has operated on skeletal genes in the human being after they left Africa, resulting in the rapid evolution of the human skeletal system and the associated diversity of phenotypesso, so that they were easily adapted to the new environment. Their research result provided an important clue for the understanding of the mechanism of population differentiation in modern the human being. The result was published online in Human Molecular Genetics.

Single-Claw Dinosaur Fossil Found

A joint survey team led by Prof. Xu Xing from the Institute of Vertebrate Paleontology and Paleoanthropology and Prof. Wang Deyou from the Scientific Academy, Department of Land and Resources, Henan Province, found a new species of single-claw dinosaur during their paleontological survey at the world famous site of dinosaur egg fossils at Xixia County, Henan Province. This dinosaur, named Xixianykus zhangi, is the first-ever single-claw dinosaur found in China and is of great significance to the study of evolution of such dinosaur groups. The result was published by an Australian magazine Zootaxa recently. The single-claw dinosaur fossil found in Zhoujiagou, Xixia County, Henan Province was collected from the Upper Cretaceous Majiacun Formation. The fossil is now collected by the Xixia Museum of Dinosaur Egg Fossils, China. Xixianykus zhangi is known as the earliest single-claw dinosaurs in the world. Many morphologic characteristics of Xixianykus zhangi assumed initial status of the morphologic characteristics of late single-claw dinosaurs. According to the analysis of morphology of the spine and hindlimb of Xixianykus zhangi, scientists inferred that such dinosaurs had very strong running ability. Single-claw dinosaurs might be the extreme cursors among dinosaurs.