March 22, 2024
Two New Publications From Mammals Assistant Curator
Two New Publications From Mammals Assistant Curator
Dr. Anderson Feijó published two papers exploring how pikas are able to survive in extreme environments and what leaf beetles reveal about the boundary between Northern Eurasia and Southern Asia.
- Pikas are emblematic animals of high mountain habitats. These mammals—closely related to rabbits and hares—can live at extremely high altitudes, reaching up to 6,000 meters (nearly 20,000 feet) in the Himalayas. Since 2017, Dr. Feijó has been pursuing projects and field surveys across China in collaboration with colleagues from the Chinese Academy of Sciences to better understand how these animals can survive such extreme environments. Another piece of this puzzle has just been published in the Journal of Mammalogy. Studying differentially expressed genes across tissues can reveal physiological adaptations associated with distinct environments, and in this study the team compared high-altitude pikas and mid-altitude pikas, analyzing sets of genes under expression in the heart, liver, spleen, lung, kidney, and brain. They found that the tissues of high-altitude pikas have an elevated expression of genes related to DNA damage repair, energy metabolism, and immune regulation (e.g., some highly expressed genes are known to inhibit the development of liver cancer, and metabolic regulation mechanisms are important to survive at low oxygen levels). The results suggest that high-altitude pikas may improve the metabolic capacity of carbon compounds and reduce reliance on oxygen as an adaptive mechanism to survive in high-altitude hypoxic environments. In addition, enhancing immune cellular performance in the liver and the expression of genes associated with cell repair are beneficial in regulating inflammation and mitigating tissue damage caused by high UV radiation. These findings illuminate the physiological demands required to survive in extremely high elevations. The team now plans to replicate these analyses for other mammals and expand to other montane regions like the Andes.
- Understanding the evolution of widespread groups of animals can shed light on the development of biogeographical realms. This requires the study of large numbers of species, knowledge of their distributional ranges, and genetic data—data that are rarely available for species-rich groups of invertebrates, severely limiting global-scale analyses. In a new study published in Journal of Biogeography, Anderson and colleagues from China, the United Kingdom, and Czech Republic found a way to partly circumvent this problem. Anderson and his colleagues were particularly interested in assessing the eastern boundary between the Palaearctic (northern Eurasia) and Oriental (southern Asia) realms as these regions were never divided by open ocean and lacked obvious physical barriers (the western boundary between these two realms is clearly defined by the Himalayas). To get at this, they focused on a highly diverse group of leaf beetles (Chrysomelidae), with nearly 40,000 species recognized, and generated hundreds of mitochondrial genomes from beetle communities in selected places to represent each of the major zoogeographic regions of the world, including areas in China, Borneo, and Panama. Based on this global dataset, they explored the geographic evolutionary history across lineages as old as 160 million years using analytical methods Anderson had developed and applied previously to understand mammal evolution in Asia. The new study shows that the Qinling Mountains located in eastern China act as a contact zone of evolutionarily deeply separated biotas of mainly (sub)tropical origin in the south from those of temperate origin in the north that have come into contact fairly recently. These findings help define the Qinling Mountains as an important biogeographical zone, harboring a mixed biota with distinct evolutionary histories, and numerous endemic species. The site-based sampling method can be widely used for other poorly known, super-diverse lineages of invertebrates and make global-scale biogeographic analyses possible beyond well-studied vertebrates.
