TY - JOUR

T1 - Camelus knoblochi genome reveals the complex evolutionary history of Old World camels

AU - Yuan, Junxia

AU - Hu, Jiaming

AU - Liu, Wenhui

AU - Chen, Shungang

AU - Zhang, Fengli

AU - Wang, Siren

AU - Zhang, Zhen

AU - Wang, Linying

AU - Xiao, Bo

AU - Li, Fuqiang

AU - Hofreiter, Michael

AU - Lai, Xulong

AU - Westbury, Michael V.

AU - Sheng, Guilian

N1 - Publisher Copyright: © 2024 Elsevier Inc.

PY - 2024

Y1 - 2024

N2 - Extant Old World camels (genus Camelus) contributed to the economic and cultural exchanges between the East and West for thousands of years.1 , 2 Although many remains have been unearthed,3 , 4 , 5 we know neither whether the prevalent hybridization observed between extant Camelus species2 , 6 , 7 also occurred between extinct lineages and the ancestors of extant Camelus species nor why some populations became extinct while others survived. To investigate these questions, we generated paleogenomic and stable isotope data from an extinct two-humped camel species, Camelus knoblochi. We find that in the mitochondrial phylogeny, all C. knoblochi form a paraphyletic group that nests within the diversity of modern, wild two-humped camels (Camelus ferus). In contrast, they are clearly distinguished from both wild and domesticated (Camelus bactrianus) two-humped camels on the nuclear level. Moreover, the divergence pattern of the three camel species approximates a trifurcation, because the most common topology is only slightly more frequent than the two other possible topologies. This mito-nuclear phylogenetic discordance likely arose due to interspecific gene flow between all three species, suggesting that interspecific hybridization is not exclusive to modern camels but a recurrent phenomenon throughout the evolutionary history of the genus Camelus. These results suggest that the genomic complexity of Old World camels’ evolutionary history is underestimated when considering data from only modern species. Finally, we find that C. knoblochi populations began declining prior to the last glacial maximum and, by integrating palaeoecological evidence and stable isotope data, suggest that this was likely due to failure to adapt to a changing environment.

AB - Extant Old World camels (genus Camelus) contributed to the economic and cultural exchanges between the East and West for thousands of years.1 , 2 Although many remains have been unearthed,3 , 4 , 5 we know neither whether the prevalent hybridization observed between extant Camelus species2 , 6 , 7 also occurred between extinct lineages and the ancestors of extant Camelus species nor why some populations became extinct while others survived. To investigate these questions, we generated paleogenomic and stable isotope data from an extinct two-humped camel species, Camelus knoblochi. We find that in the mitochondrial phylogeny, all C. knoblochi form a paraphyletic group that nests within the diversity of modern, wild two-humped camels (Camelus ferus). In contrast, they are clearly distinguished from both wild and domesticated (Camelus bactrianus) two-humped camels on the nuclear level. Moreover, the divergence pattern of the three camel species approximates a trifurcation, because the most common topology is only slightly more frequent than the two other possible topologies. This mito-nuclear phylogenetic discordance likely arose due to interspecific gene flow between all three species, suggesting that interspecific hybridization is not exclusive to modern camels but a recurrent phenomenon throughout the evolutionary history of the genus Camelus. These results suggest that the genomic complexity of Old World camels’ evolutionary history is underestimated when considering data from only modern species. Finally, we find that C. knoblochi populations began declining prior to the last glacial maximum and, by integrating palaeoecological evidence and stable isotope data, suggest that this was likely due to failure to adapt to a changing environment.

KW - ancient DNA

KW - Camelus knoblochi

KW - evolution

KW - extinction

KW - interspecific hybridization

KW - nucleotide diversity

KW - phylogenetic tree

KW - Pleistocene

KW - stable isotope

KW - two-humped camel

U2 - 10.1016/j.cub.2024.04.050

DO - 10.1016/j.cub.2024.04.050

M3 - Journal article

C2 - 38754423

AN - SCOPUS:85194330866

VL - 34

SP - 2502-2508.e5

JO - Current Biology

JF - Current Biology

SN - 0960-9822

IS - 11

ER -