Abstract
The Asian elephant (Elephas maximus), a keystone species, faces
significant threats from habitat loss, poaching, and population
fragmentation. Understanding the evolutionary history of its subspecies
is essential for developing targeted conservation strategies and
mitigating risks to their survival.This study introduces, for the first
time, whole-genome sequencing (WGS) data from predominantly wild-origin
Asian elephants housed in European zoos, covering the distribution range
of Asian elephants. Our data aims to validate the Asian elephant
subspecies designation and address ambiguities about their origin,
particularly concerning Bornean and Sri Lankan elephants. Analysis
reveals a clear population structure with relatively recent splits,
delineating three distinct genetic clusters: Borneo, Sumatra, and
Mainland, with Sri Lanka forming an additional group. Hypotheses on the
origin of Bornean elephants—native dispersal or human
introduction—are explored. Our data reflects the current Asian
elephant subspecies designation. This study is estimating the divergence
time between Bornean and Sumatra elephants, around 170,000 years ago.
Their genome also exhibited severe bottlenecks as recently as 8 and 38
generations ago, further supporting hypotheses of introduction. The
divergence of Sri Lankan elephant from the Mainland is estimated at
48,000 years ago, with Sri Lankan elephants predominantly clustering
with those from Myanmar, possibly due to historical trade networks.
Additionally, the Sumatra elephant is confirmed as a distinct
subspecies. Furthermore, the study discusses genetic management
strategies for ex-situ populations, emphasizing the importance of
implementing cluster-specific conservation measures. Despite data
constraints, recognizing Bornean elephants as a distinct subspecies,
informs conservation strategies, and suggests avenues for further
research.