Based on a long-term study of the Himalayas, the team of Qian Jing, a researcher at the Kunming Institute of Zoology of the Chinese Academy of Sciences, reconstructed the dynamic history of space-time evolution of most of the amphibian groups present in the region, explored the hypothesis of important geological and historical events such as the rise of the Himalayas and the development of the South Asian monsoon, and revealed the effects of these events on biological differentiation and migration. The findings, published in the National Science Review and NSR, are based on the title of Herpetological Phylogeographic Analyses Support a Miocene Focal Point of Himalayan Uplift and DiversIfication.
The evolutionary history of the Hishan amphibian reptile
Located in the southern part of the Qinghai-Tibet Plateau, the Himalayas are the highest average mountain range in the world, with 10 peaks above 8,000 meters, including Mount Qomolangma, the world’s highest peak, at an altitude of 8848.43 meters. The Himalayas are also one of the world’s 34 biodiversity hotspots, with their special environment, huge altitude differences, rich vegetation gradients and unique animal groups.
Based on first-hand data collected by the team and integrated published species sequence data from GenBank, multigene sequence fragments of 14 departments and 1,628 amphibian reptiles were collected, involving 182 Himalayan species, or about 60 percent of the recorded species in the region. By constructing species evolution trees, combining time correction points and species distribution information, this paper explores the dynamic evolution pattern of amphibians distributed in the Himalayas.
The diversity of living amphibian reptiles in the Himalayas began to accumulate as early as the Paleocene. Overall, the trend of change in in-place and interregional diffusion events was generally consistent, slow in the early stages, and the rate of species accumulation accelerated from the end of the Oligocene to the early Mesothrene. Around the middle of the Mesocentr period, about 15 million years ago, the himalayan species accumulation rate peaked and then began to decline.
Animal evolution supports the “progressive bulging hypothesis”
As the youngest and highest mountain range on Earth, the Himalayas were formed by the collision of the Indian subsection with the Eurasian Plate. However, there is still controversy over the history and mechanism of the himalayas’ ascent. Early studies have taken the Himalayas and plateaus as a whole, proposing the “early Himalayan rise hypothesis”, that the Himalayas were formed in the early new generation. However, given the apparent differences between the plateau and the Himalayas in the history of geological ascent, the current geological evidence has generally rejected this hypothesis.
At present, there are two hypothreaes about the history of the rise of the Himalayas: the late Orogeny Hypothesis, which is supported by hydrological and thermal evidence that the Himalayas did not reach their current height until the middle of the Last World; It wasn’t until Miocene began to rise rapidly that it reached its current height.
The evolution of a regional biota is closely related to geological climate change, and during mountain range rise, the increase in heterogeneity of the landscape produces a large number of geographical isolation opportunities and ecological differentiation, thus promoting the formation of large numbers of native species. Corresponding to these two geological hypothes, two distinct patterns of biological evolution can be predicted: (1) If the recent uplind hypothesis is true, the cumulative acceleration time of amphibian reptile species in the Himalayas will occur in the middle or after the last world. (2) If the progressive bulging hypothesis is established, it will see the accumulation of local species begin in the late Paleo-Neolithic period and accelerate in the Meso-New World.
The study’s re-established evolutionary dynamic pattern of amphibian reptiles in the Xishan region supports the “progressive upliging hypothesis.” To study and analyze the evolutionary history of amphibian reptile systems in the Himalayas for the first time, and to explore different geological hypothrea. From the perspective of biodiversity conservation, the study is of great significance, and the results support the Himalayan region as an important cradle of species formation and differentiation. The Himalayas are a world-class treasure trove of biological genes with so many native species concentrated in such a small area. The protection of the ecological environment and habitat of the area should be strengthened in order to protect these precious and unique biological resources.
Xu Wei, Ph.D. student at Kunming Animal Institute, is the first author of the paper and a professor at the University of Texas at Austin, David M. Hillis is a co-author of the paper. The research work is supported by the Second Qinghai-Tibet Plateau Comprehensive Scientific Expedition Research Project, the Chinese Academy of Sciences Strategic Pilot Science and Technology Special (Class A) “Pan-Third Pole Environmental Change and Green Silk Road Construction”, and the Animal Sub-bank of the Wildlife Species Resource Bank of Southwest China (National Major Science and Technology Infrastructure Special). Car Jing by the Chinese Academy of Sciences sent to study abroad program support, David M. Hillis is funded by the International Visiting Scholars Program of the Chinese Academy of Sciences.
Map of the Himalayan mountains and representative amphibian reptiles
Evolution of amphibian reptiles in the Himalayas. Overall evolutionary patterns (a), diffusion patterns in the Himalayas and else regions (b)
There are two kinds of bulging hypothosis in the Himalayas: progressive bulging hypothesis (a) and recent uplind hypothesis (b), and corresponding biological evolutionary process prediction (c, d). Figure c is more consistent with the actual evolutionary process
Source: Kunming Institute of Zoology, Chinese Academy of Sciences