The fact that all known Languages employ syntax is used to support the genetic origins of Language Development.
What appears to be missing, however, from the symbolic communication of primates is true syntax.
When answering a question (please note that their symbolic communication is all through the visual modality), the gorilla will mimic the syntax of the questioner.
But when they generate a spontaneous sentence, there appears to be no structure to their word order.
Syntax, then is what separates the men from the gorillas.
A second interesting fact is that there is no culture known in the world, present or past, that has a language without syntax! Nor has there ever been found a language with a primitive syntax.
Even the language of the aborigines in Australia has a syntax that is no less complex than any other language.
This encourages natavists like Chomsky to predict a genetic link to language development.
NOTES: Here is some information on the language of the Australian Aborigines.