Good news, roots fans, on two fronts, one a report to be discussed in another post of a game chimpanzees play better than humans, and this one, a report from linguists detailing the integration hypothesis, wherein human language evolved from two lines, primates and birds.
The integration hypothesis posits two features of animal communication which merged to produce the virtually unbounded creativity of human language. First, the expressive layer derives from birdsong, thus the picture of a mocking bird, one of my favorites and frequenter of our farmyard, which sings a a great variety of songs, often copying other birds while also carrying on its own favorite triplets of various forms. This component is reflected in the melodic features of our language. The second is the lexical layer, derived from primate communication, and is reflected in the semantic content of our language. The researchers cite a primate on the endangered species list, the silver gibbon, that is unusual in that it sings, i.e., it has a complex repertoire of sung vocalizations (as opposed to regular calls, such as grunts, clicks, whistles, etc), as it communicates with its conspecifics, kin and familiars.
The researchers are not sure how these two evolutionary lines would have merged but their effort is to understand the antecedents of human language, which we can only do indirectly. Certainly more research will be helpful. For example, is the gibbon’s vocalization lateralized to the left hemisphere? Birds, we know, have a distinctly different neurological pattern because their brains embryologically start as male and then some are feminized. Mammalian embryos start out with female brains and then some are masculinized. And of course, some of the changes result in variegated patterns.
What makes this research so interesting is that much of the world denies any biological antecedents of human language; they cannot see any intermediate steps leading up to the remarkable generative capability we have. However these scientists are looking with new eyes and finding much to see (and to hear). Here is a link: http://newsoffice.mit.edu/2014/human-language-deep-origins-0611