受非法捕獵、棲息地減少及破碎化等威脅，極危的蘇門答臘犀牛只餘下少於100隻。研究發現牠們保留了比預期中多的遺傳多樣性，即牠們有較好的基因對抗氣候變化及疾病。可惜族群細小，當中出現輕微的近親繁殖，令研究團隊非常擔憂，因過去就有一個群族因突發爆發近親繁殖而導致整個滅絕。

There only fewer than 100 of critically endangered Sumatran rhinos, and they are mainly  threatened by poaching, habitat loss and fragmentation. Research found they retain higher genetic diversity as expected, means they are more likely to survive threats like climate change or disease. However, with small population size they show low levels of inbreeding. This worries the researchers because another subpopulation showed a sudden outbreak of inbreeding before their extinction.