Lamarkian evolution implies that characteristics earned in one generation may be passed on the next generation. This does not happen with animals. Giraffe necks did not grow longer because successive generations of giraffes stretched their necks and passed down the stretch. Giraffes have long necks because the ones born with longer necks tended to be better suited to an environment of high hanging food, and so survived to pass on long necked genes. Languages however can pick up new tricks and hand them on with a net gain in efficiency.
Symbolism is a powerful tool in the hands of evolutionary process.
When ants use pheremones to mark out paths to food, points of danger and other myriad communication, they are using language. They are abstracting ideas into symbols . Languages are living things. No-one would deny that modern South Australian computer jargon would be incomprehensible to ants. There is a long way from bird song to sonnets .