There is none. On the evolutionary line, communication goes as far as animals. It has some stepping stones that has been speculated in scientific society but because none of them were written, no one knows. Our certain knowledge comes from the history of writing. And the method is tracing back the current languages and speculating the structure, meaning and verbal qualities of the ancient writings. In any case it isn't latin. Latin is a fairly very young language. The oldest writing we know is from Sumer Civilization of Ancient Mesopotamia from 3200 BCE.
in Genesis on the 6th day God created man and woman both created he them male and female the language spoken by them is now called ancient Hebrew different than Hebrew now after the Tower of Babel all other languages came in to so no one could communicate they all moved separate ways tribe from tribe language from language