 Such theories rely heavily on the possibility of the evolution of language being explained in terms of saltation or random mutation. This postulate has come under significant scrutiny (see Steedman 2017). Saltation views, however, rely on one of the core assumptions mentioned in the quote above, i.e. that language evolved circa 100 000 years old. This central claim has recently been challenged by Everett (2017) who cites paleontological evidence from the alleged nautical abilities of Homo Erectus to dismantle this timeline. If true, this would mean that language evolved around two million years ago and random mutation need not be the only viable explanation as many in the Essentialist framework assume (see Progovac 2015 for a particular gradualist account). 