Here is Lucretius expressing these ideas in Book 4 line 823

This is pure Darwinian thinking – the continual modification and development of things that existed, honed by Natural selection . Speech is a by-product of tongues. The tongue was not created that we might speak. I wonder if Darwin ever read Epicurus or Lucretius. We have On the Origin of Species in the library (4th edition 1886).
Epicurus was a vegetarian who espoused basic foods such as porridge. Over two millennia his ideas have become twisted and perverted so we now tassociate his name with fine dining, rich foods and gluttony. Epicurus would not have recognized this.
Epicurus thought the role of Philosophy was to enable us to be happy. You cannot defeat nature – you might lose your health or fail in your career but by studying Philosophy you can develop a complete control of your inner self, one’s attitudes, opinions and affections. This mental discipline will provide an armour against grief, envy, anger, obsessions and other passions. Philosophy was a way of life. It provided guidelines for daily practice, customs and diet to help followers to achieve permanent interior happiness, immune to the blows of fortune. He did not mean, however, a hedonistic society exemplified by gluttony. So in his ideas there was no need for the gods, for spirituality or even caring for your fellow man. All decisions should be based on the degree of pleasure or pain deriving from them. You can see then how easily this idea could be perverted into seeking excess in sex, drink and food.

These all wrote in Greek which was a language of limited spread but Lucretius was reading them in 50BC, 300 years later, and he was a Roman writing in Latin – a more Universal language. Epicurus was first translated by Traversari in 1433. I think Lucretius read Epicurus from the Greek and he developed the ideas of these early philosophers in the only book of his which survives. This is an epic poem called De Rerum Natura – On the nature of things . It was written in Latin in six books or three pairs of books. The first pair dealt with atoms, the second with the soul, and the third with the cosmos and mortality.  They are now bound in one book of 7,400 lines. His was an expositor rather than an original thinker and his skill was in presenting difficult ideas and putting them into verse to make them more palatable. Lucretius’ work totally disappeared until rediscovered by Poggio Bracciolini in 1417. Poggio was the personal secretary to John XXIII, and a prolific manuscript hunter travelling all over Italy, Germany and Switzerland. His greatest discovery was in a monastery in the mountains above Lake Constance. He made a copy of De Rerum Natura and presented it to to an Italian book collector called Niccolo Niccoli. Niccoli held the book for over 10 years whilst he translated it into Latin without allowing anybody to see it. He did not even allow Poggio to make a copy of it. De rerum natura was finally published in 1600 which allowed people to study it. The Charlecote copy dates from 1675 and my copy from 1717.