Endurance running and the evolution of Homo

Striding bipedalism is a key derived behaviour of hominids that possibly originated soon after the divergence of the chimpanzee and human lineages. Although bipedal gaits include walking and running, running is generally considered to have played no major role in human evolution because humans, like apes, are poor sprinters compared to most quadrupeds. Here we assess how well humans perform at sustained long-distance running, and review the physiological and anatomical bases of endurance running capabilities in humans and other mammals. Judged by several criteria, humans perform remarkably well at endurance running, thanks to a diverse array of features, many of which leave traces in the skeleton. The fossil evidence of these features suggests that endurance running is a derived capability of the genus Homo, originating about 2 million years ago, and may have been instrumental in the evolution of the human body form.     

A fossil skull probably of the genus Homo from Sterkfontein, Transvaal.

A skull with numerous Homo features was discovered at Sterkfontein, near Krugersdorp, Transvaal, in August 1976. It stems from member 5 of the Sterkfontein Formation, with stone tools and with fauna pointing to an age of 2.0-1.5 Myr. The underlying member 4 contains Australopithecus africanus, no stone tools, and fauna dated 3.0-2.5 Myr. The new find supports the view that the Sterkfontein toolmaker was not the earlier A. africanus, but a later hominid related to Homo habilis. By a remarkable double coincidence, the first pieces of the new skull, Stw 53, were found on August 9, 1976, 40 years to the day after Robert Broom's first visit to Sterkfontein, while the last part came to light on August 17, the 40th anniversary of Broom's first discovery of a hominid cranium at Sterkfontein. Although most of the fragments were found in a decalcified pocket of cave earth, one large part of the calvaria was still present in the calcified wall of the pocket, thus establishing indisputably the provenance of the specimen.     

Earliest Homo.

The origin of our own genus, Homo, has been tentatively correlated with worldwide climatic cooling documented at about 2.4 Myr (million years). It has also been conjectured that members of Homo made the first stone tools, currently dated at 2.6-2.4 Myr. But fossil specimens clearly attributable to Homo before about 1.9 Myr have been lacking. In 1967 a fossil hominoid temporal bone (KNM-BC1) from the Chemeron Formation of Kenya was described as family Hominidae gen. et sp. indet. Although a surface find, its provenance within site JM85 (BPRP site K002) was established and a stratigraphic section provided indicating the specimen's position. This evidence has been affirmed but the exact age of the fossil was never determined, and the absence of suitable comparative hominid material has precluded a more definitive taxonomic assignment. Here we present 40Ar/39Ar age determinations on material from the hominid site indicating an age of 2.4 Myr. In addition, comparative studies allow us to assign KNM-BC1 to the genus Homo, making it the earliest securely known fossil of our own genus found so far.     

Origin and evolution of new genes

Organisms have variable gcnome sizes and contain different numbers of genes. This difference demonstrates that new gene origination is a fundamental process in evolutionary biology. Though the study of the origination of new genes dated back more than half a century ago, it is not until the 1990s when the first young genejingwei was found that empirical investigation of the molecular mechanisms of origination of new genes became possible. In the recent years, several young genes were identified and the studies on these genes have greatly enriched the knowledge of this field. Yet more details in a general picture of new genes origination are to be clarified. We have developed a systematic approach to searching for young genes at the genomic level, in the hope to summarize a general pattern of the origination and evolution of new genes, such as the rate of new gene appearance, impact of new genes on their host genomes, etc.     

Origin, evolution and extinction of Cathaysia flora

Recent research results showed that the Cathaysia flora originated and developed from the global uniformLepidodendropsis flora of the Early Carboniferous, which had already become an independent flora in the early Late Carboniferous (Namurian B to C). The center of origin of the Cathaysia flora is restricted to the North China Plate. On the basis of the successional characteristics of the Cathaysia flora in different geological ages, it may be divided into seven evolutionary stages. The evolutionary trend of the Cathaysia flora, as a whole, was characterized by the gradual increase of the typical Cathaysian elements in the sequence from the early Late Carboniferous to the early Late Permian, which began to decline during the late Late Permian. The climatic differentiation, tectonic movement, oceanic circulation, palaeogeographical environment, extraterrestrial event and plant evolution caused the mass extinction of the Cathaysia flora on a large scale by the end of the Permian.     

Cladistic analysis of continuous modularized traits provides phylogenetic signals in Homo evolution

Evolutionary novelties in the skeleton are usually expressed as changes in the timing of growth of features intrinsically integrated at different hierarchical levels of development. As a consequence, most of the shape-traits observed across species do vary quantitatively rather than qualitatively, in a multivariate space and in a modularized way. Because most phylogenetic analyses normally use discrete, hypothetically independent characters, previous attempts have disregarded the phylogenetic signals potentially enclosed in the shape of morphological structures. When analysing low taxonomic levels, where most variation is quantitative in nature, solving basic requirements like the choice of characters and the capacity of using continuous, integrated traits is of crucial importance in recovering wider phylogenetic information. This is particularly relevant when analysing extinct lineages, where available data are limited to fossilized structures. Here we show that when continuous, multivariant and modularized characters are treated as such, cladistic analysis successfully solves relationships among main Homo taxa. Our attempt is based on a combination of cladistics, evolutionary-development-derived selection of characters, and geometric morphometrics methods. In contrast with previous cladistic analyses of hominid phylogeny, our method accounts for the quantitative nature of the traits, and respects their morphological integration patterns. Because complex phenotypes are observable across different taxonomic groups and are potentially informative about phylogenetic relationships, future analyses should point strongly to the incorporation of these types of trait.     

Genetics and the making of Homo sapiens

Understanding the genetic basis of the physical and behavioural traits that distinguish humans from other primates presents one of the great new challenges in biology. Of the millions of base-pair differences between humans and chimpanzees, which particular changes contributed to the evolution of human features after the separation of the Pan and Homo lineages 5-7 million years ago? How can we identify the 'smoking guns' of human genetic evolution from neutral ticks of the molecular evolutionary clock? The magnitude and rate of morphological evolution in hominids suggests that many independent and incremental developmental changes have occurred that, on the basis of recent findings in model animals, are expected to be polygenic and regulatory in nature. Comparative genomics, population genetics, gene-expression analyses and medical genetics have begun to make complementary inroads into the complex genetic architecture of human evolution.     

Origin of a gene regulatory mechanism in the evolution of echinoderms

A rich diversity of ancient sea urchin lineages survives to the present. These include several advanced orders as well as the cidaroids, which represent the group ancestral to all other sea urchins. Here we show that all advanced groups of sea urchins examined possess in their eggs a class of maternal messenger RNA (mRNA) encoded by the evolutionarily highly conserved alpha-subtype histone genes. The maternal histone mRNAs are unique in their time of accumulation in oogenesis, their localization in the egg nucleus and their delayed timing of translation after fertilization. Cidaroid sea urchins as well as other echinoderm classes, such as starfish and sea cucumbers, possess the genes but do not have maternal alpha-subtype histone mRNAs in their eggs. Thus, although all the echinoderms examined transcribe alpha-subtype histone genes during embryogenesis, the expression of these genes as maternal mRNAs is confined to advanced sea urchins. The fossil record allows us to pinpoint the evolution of this mode of expression of alpha-histone genes to the time of the splitting of advanced sea urchin lineages from the ancestral cidaroids in a radiation which occurred in a relatively brief interval of time approximately 190-200 Myr ago. The origin of a unique gene regulatory mechanism can thus be correlated with a set of macroevolutionary events.     

Origin and evolution of new exons in the rodent zinc finger protein 39 gene

The origin of new structures and functions is an important process in evolution. In the past decades, we have obtained some preliminary knowledge of the origin and evolution of new genes. However, as the basic unit of genes, the origin and evolution of exons remain unclear. Because young exons retain the footprints of origination, they can be good materials for studying origin and evolution of new exons. In this paper, we report two young exons in a zinc finger protein gene of rodents. Since they are unique sequences in mouse and rat genome and no homologous sequences were found in the orthologous genes of human and pig, the young exons might originate after the divergence of primates and rodents through exonization of intronic sequences. Strong positive selection was detected in the new exons between mouse and rat, suggesting that these exons have undergone significant functional divergence after the separation of the two species. On the other hand, population genetics data of mouse demonstrate that the new exons have been subject to functional constraint, indicating an important function of the new exons in mouse. Functional analyses suggest that these new exons encode a nuclear localization signal peptide, which may mediate new ways of nuclear protein transport. To our knowledge, this is the first example of the origin and evolution of young exons.     

Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins.

A modern human-like sequence of dental development, as a proxy for the pace of life history, is regarded as one of the diagnostic hallmarks of our own genus Homo. Brain size, age at first reproduction, lifespan and other life-history traits correlate tightly with dental development. Here we report differences in enamel growth that show the earliest fossils attributed to Homo do not resemble modern humans in their development. We used daily incremental markings in enamel to calculate rates of enamel formation in 13 fossil hominins and identified differences in this key determinant of tooth formation time. Neither australopiths nor fossils currently attributed to early Homo shared the slow trajectory of enamel growth typical of modern humans; rather, both resembled modern and fossil African apes. We then reconstructed tooth formation times in australopiths, in the approximately 1.5-Myr-old Homo erectus skeleton from Nariokotome, Kenya, and in another Homo erectus specimen, Sangiran S7-37 from Java. These times were shorter than those in modern humans. It therefore seems likely that truly modern dental development emerged relatively late in human evolution.     

缘起与嬗变：东北游牧民族弓马文化的历史演变、时代价值与发展路径

为了把握东北游牧民族弓马文化在新时代的价值,提升其传承发展成效,更好的服务新时代体育强国与文化强国建设,研究运用文献资料法、深入访谈法、逻辑分析法对我国东北游牧民族弓马文化的缘起进行追溯,沿循缘起→演变→蜕变→发展的嬗变主线,对游牧民族弓马文化嬗变与发展的形式、蕴意、多元发展进行了阐释;解析了弓马文化的民族精神、品牌兴村、独特珍贵遗产、蕴含教育价值、铸牢中华民族共同体意识等时代价值。提出了东北游牧民族弓马文化传承与发展的科学路径：深入开展挖掘与整理,强化弓马文化申遗保护;推进弓马文化进校园,筑牢校园文化共同体;打造弓马文化旅游品牌,与经济建设协同发展;举办区域性庆典及运动会,加强弓马文化竞赛与交流;推动弓马文化融入全民健身,促进优秀传统文化数据传承。     

Molecular evolution of stress-response gene Leptin in high-altitude Chinese snub-nosed monkeys (Rhinopithecus genus)

Chinese snub-nosed monkeys (genus Rhinopithecus, subfamily Colobinae), including R. bieti, R. brelichi and R. roxellana, are well-known as the non-human primates with the highest known altitudinal distribution. They represent an interesting model organism of adaptation to the extreme environmental stresses. However, no study at the molecular level has yet been reported for the high-altitude adaptation in Chinese snub-nosed monkeys. Leptin, as an adipocyte-derived hormone, is believed to play an important role in energy homeostasis in adaptation to high altitude environments. In the present study, we sequenced and compared leptin sequences of the Chinese snub-nosed monkeys (R. bieti and R. roxellana) with their lowland close relative R. avunculus and other Colobines. Unexpectedly, no amino acid changes were observed in the 7 Colobinae species examined, including the 2 Chinese snub-nosed monkeys, indicating no difference in the evolutionary pattern of the Leptin gene between high-altitude monkeys and their lowland counterparts. In contrast to a previous finding of adaptive evolution of Leptin gene in plateau pikas, our study suggests that this gene may not have an important role in high-altitude adaptation of Chinese snub-nosed monkeys. Other nuclear genes associated with energy metabolism, or mitochondrial genes, are most likely to be involved the molecular mechanism underlying adaptation of these monkeys to cold and hypoxia associated with the highland environment.     

中国鞭隰蝇属研究 (双翅目：花蝇科)

在中国首次确立鞭隰蝇属ZaphneR．-D．分类阶元,订正了该属15种的属名,记录了分布地,同时将AnthomyzahyalipennisZett,1855学名订正为Zaphneinuncta(Zett．,1838)．