Were Twins The First Talkers?

Is is possible that the first uses of language came from identical twins? If language development is evolutionary, then the first individual with language abilities would have needed someone to talk to--and understand the speech--in order to have the ability continue through a population. It is hard to see a single talker with no one who is able to understand having a procreative advantage.

Since we also know that language is much more easily learned as a child than an adult, the first child born with language abilities would see those abilities fade with age without being able to talk to others to "activate" it. In addition, by the time this individual reached an age of reproduction, the language ability would have largely passed and, therefore, communication with offspring who might also have the inherited genetic disposition for language, would likely not happen for the same reason it couldn't communicate with others when this individual was an infant.

However, if there were a set of identical twins born with the same ability for language, they could potentially talk to each other by developing their own language--as we know happens with modern human twins--and pass it on to their offspring. So, there is a high probability that the use of language by any of our ancestral populations was a side-effect of the birth of twins.