Tracking the evolution of language and speech

In 1973 theodosius dobzhansky wrote that “nothing in biology makes sense except in the light of evolution.” This dictum applies equally well to human language and speech, which have an evolutionary history that has yet to be fully discovered. Unfortunately, apart from their sometimes fossilized bones and archaeological traces of their behavior, nothing remains of our distant ancestors. Yet the mark of our evolution may be discerned in our modern bodies, brains, and even our vocal tracts.

Evidence from seemingly unrelated disciplines suggests that the specialized anatomy and neural mechanisms that confer fully human speech, language, and cognitive ability reached their present state sometime between 100,000 and 50,000 years ago. The appearance of these attributes relatively late in our evolution—well after our species originated about 200,000 years ago—has important implications for how we think about ourselves, our ancestors, and our collateral relatives (including the Neanderthals who evolved separately from our common ancestor starting about 500,000 years ago). In fact, the appearance of modern human bodies well before the appearance of what we consider to be modern human behavior — our higher mental processes such as complex thought, language, and symbolic behavior—suggests that there was something about our early modern ancestors that allowed them to develop into our more recent, fully modern selves. That building block may have been something as simple as speech, the vocal transmission of information at a very fast rate.