在現(xiàn)代西非人的DNA中，發(fā)現(xiàn)了一種不為人知的已滅絕人類的“幽靈”

在現(xiàn)代西非人的DNA中，發(fā)現(xiàn)了一種不為人知的已滅絕人類的“幽靈”

The gene pool of modern West Africans contains the 'ghost' of a mysterious hominin, unlike any we've detected so far. Similar to how humans and Neanderthals once mated, new research suggests this ancient long-lost species may have once mingled with our ancestors on the African continent.

現(xiàn)代西非人的基因庫中含有一種神秘古人類的“幽靈”，這與我們迄今為止發(fā)現(xiàn)的任何古人類都不同。類似于人類和尼安德特人曾經(jīng)的交配方式，新的研究表明，這一消失已久的古老物種可能曾經(jīng)與我們在非洲大陸的祖先交配過。

Using whole-genome data from present-day West Africans, scientists have found a small portion of genetic material that appears to come from this mysterious lineage, which is thought to have split off from the human family tree even before Neanderthals.

利用現(xiàn)代西非人的全基因組數(shù)據(jù)，科學(xué)家們發(fā)現(xiàn)了一小部分遺傳物質(zhì)，似乎來自這個神秘的世系，這個世系被認為早在尼安德特人之前就從人類的族譜中分離出來了。

Today, it's thought (although still being debated) that anatomically modern humans originated in Africa, and that once these populations migrated to Europe and Asia, they interbred with closely-related species like Neanderthals and Denosovans.

今天，人們認為(盡管仍在爭論中)，從解剖學(xué)上講，現(xiàn)代人類起源于非洲，一旦這些種群遷移到歐洲和亞洲，他們就會與尼安德特人和德諾索瓦人等親緣關(guān)系很近的物種雜交。

As such, modern West Africans, like populations in Yoruba and Mende, do not possess genes from either of these ancient species, but that doesn't mean there was no intermixing. In fact, recent evidence suggests the genetic past of West Africans may contain a similarly juicy narrative.

因此，現(xiàn)代西非人，就像約魯巴人和門德人一樣，并不擁有這兩種古老物種的基因，但這并不意味著沒有混合。事實上，最近的證據(jù)表明，西非人的遺傳歷史可能包含著類似的有趣故事。

The idea is hard to confirm, because ancient human remains and DNA are scarce on the African continent and even harder to find in West Africa.

這一觀點很難得到證實，因為在非洲大陸上，古人類遺骸和DNA非常稀少，在西非更難找到。

Fortunately there is one way to get an idea of how ancient humans mixed that doesn't involve studying remains: modern genomics. Researchers decided to compare 405 modern genomes from the Yoruba and Mende populations with genomes from Neanderthals and Denisovans.

幸運的是，有一種方法可以了解古代人類是如何混合在一起的，而不需要研究遺骸:現(xiàn)代基因組學(xué)。研究人員決定將約魯巴人和門德人的405個現(xiàn)代基因組與尼安德特人和丹尼索瓦人的基因組進行比較。

To their surprise, they also found traces of another as-yet-unknown ancient hominin species in their genomes.

令他們驚訝的是，他們還在他們的基因組中發(fā)現(xiàn)了另一種尚不為人知的古人類的蹤跡。

Similar to how modern humans outside of Africa still hold traces of Neanderthal genes, the authors found populations in West Africa derived between 2 and 19 percent of their genetic ancestry from this as-yet-undiscovered ancient hominin.

類似于非洲以外的現(xiàn)代人仍然保留著尼安德特人的基因痕跡，作者發(fā)現(xiàn)西非的人群有2%到19%的遺傳祖先來自于這種至今未被發(fā)現(xiàn)的古人類。

Interestingly, this isn't the first time 'ghost' species of unknown extinct ancestors have been found in modern DNA. Researchers looking at Eurasian DNA have previously found traces of at least three as-yet-undiscovered ancient hominins in modern human genomes. But this is a first for modern West African DNA.

有趣的是，這并不是第一次在現(xiàn)代DNA中發(fā)現(xiàn)已經(jīng)滅絕的未知“幽靈”物種。研究歐亞人DNA的人員此前在現(xiàn)代人類基因組中發(fā)現(xiàn)了至少三種尚未發(fā)現(xiàn)的古人類的蹤跡。但這是首次發(fā)現(xiàn)現(xiàn)代西非DNA。

The study was published in Science Advances.

這項研究發(fā)表在《科學(xué)進展》雜志上。