It is likely impossible to quantify the evolution of human language, for the evolutionary process is a continuous one, rather than discrete. In this respect, “linguistic speciation” shares an inherent continuousity with biological evolution. Neither a “species” or a “language” is a fixed entity, but an adaptive moment amidst constant change. Along these same lines, I wonder, how long does it take for an “invasive” species or an immigrant to become “native” following its arrival? Naturalization is likewise a continuous process. My point here is that these threshold distinctions, “language,” “species,” “native,” are made arbitrarily, likely for the purpose of maintaining and reinforcing the power relations of the distinguisher.

JM Kincaid