translation.en: But that doesn't mean that all, or many, or most of today's attested languages couldn't descend perhaps from one that's much younger than that, like say 20,000 years, or something of that kind. It's what we call a bottleneck.
translation.zh: 但是这也不表明所有的或者大多数 现今得到确认的语言不是源自 一个更年轻的，可能是2万年前的源头， 或者诸如此类的来源。这也就是我们所谓的瓶颈。