Widely distributed taxa provide an opportunity to compare biogeographic responses to climatic fluctuations on multiple continents and to investigate speciation. We conducted the most geographically and genomically comprehensive study to date of the red fox (Vulpes vulpes), the world's most widely distributed wild terrestrial carnivore. Analyses of 697 bp of mitochondrial sequence in ~1000 individuals suggested an ancient Middle Eastern origin for all extant red foxes and a 400 kya (SD = 139 kya) origin of the primary North American (Nearctic) clade. Demographic analyses indicated a major expansion in Eurasia during the last glaciation (~50 kya), coinciding with a previously described secondary transfer of a single matriline (Holarctic) to North America. In contrast, North American matrilines (including the transferred portion of Holarctic clade) exhibited no signatures of expansion until the end of the Pleistocene (~12 kya). Analyses of 11 autosomal loci from a subset of foxes supported the colonization time frame suggested by mtDNA (and the fossil record) but, in contrast, reflected no detectable secondary transfer, resulting in the most fundamental genomic division of red foxes at the Bering Strait. Endemic continental Y-chromosome clades further supported this pattern. Thus, intercontinental genomic exchange was overall very limited, consistent with long-term reproductive isolation since the initial colonization of North America. Based on continental divergence times in other carnivoran species pairs, our findings support a model of peripatric speciation and are consistent with the previous classification of the North American red fox as a distinct species, V. fulva.
The Chinese giant salamander Andrias davidianus is the largest living amphibian. Most wild populations are threatened and some are already extinct. The Chinese government has declared the species a Class II Protected Species, and it is listed as Critically Endangered in the Chinese Red Book of Amphibians and Reptiles and as Data Deficient on the IUCN Red List. Populations of the species have declined sharply in both range and number since the 1950s because of habitat loss and fragmentation, and hunting for the commercial luxury food trade. Remaining populations appear to be distributed in 12 areas across 17 provinces in the mountainous areas of the middle Yangtze, Yellow and Pearl Rivers. Since the 1980s, 14 nature reserves, with a total area of more than 355,000 ha, have been established for the conservation of the Chinese giant salamander. We carried out habitat and questionnaire surveys for the species in 13 locations, and based on the results and on the little amount of published information, most of it in Chinese, we assess the current status of the species and make recommendations for its conservation management. Conservation of the Chinese giant salamander should be given a high priority and considered an important part of wetland management.
Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are highly significant infectious diseases occurring worldwide and caused by metacestodes of tapeworms Echinococcus granulosus and E. multilocularis, respectively. Both human CE and AE have highest prevalence rates in western and northwestern China. Livestock is the main intermediate host of E. granulosus, and wild small mammal are the main intermediate hosts of E. multilocularis. Since they range freely in pastoral areas, prey on wild small mammals and offal of livestock after slaughter, and have close relationships with humans, domestic dogs are the most important definitive host of both Echinococcus spp. with the highest risk of transmitting CE and AE to humans. Pastoralism is the occupation with the highest risk of being infected with the both kinds of echinococcosis due to the proximity of livestock, dogs, and wildlife host species. In this review, we summarize the epidemiology of human echinococcosis, the situation of parasite transmission in animal hosts, and possible transmission patterns in China. In addition, human activities and their potential influence on the transmission of echinococcosis are also discussed.
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