Evolution was largely theorized and understood down to the nuance that each parent contributed to a 'doubled seed' for trait inheritance and that trait success depended on survival of the fittest well before Jesus was even born.
(In fact, the author who wrote the only surviving book detailing this used the specific language of calling failed biological reproduction as "seed falling by the wayside of a path" around 80 years before the parable of the sower described how seed that fell by the wayside of the path didn't reproduce but that which found fertile soil produced more and more - a parable unanimously spoken in public in canon but provided a secret explanation thereafter and one believed by 'heretics' to have been referring to seeds described extremely similar to how Leucretius described his "seeds of things" in De Rerum Natura, the aforementioned book. Also, in the extra-canonical scripture this 'heretical' group followed, the parable of the sower immediately followed a couplet of sayings about how no matter if lion ate man or man ate lion that man was inevitable and how the human being was like a large fish selected from many small fish in the sea.)
It means people were debating intelligent design vs evolution at a time when people used to pee on their hands to clean them.
And at that time, they had no scientific methods to evaluate which side was correct, so the people who in hindsight were proven correct were able to be dismissed and forgotten by their peers and later generations.
Leucretius described light as made up of tiny indivisible parts that moved really quickly. The experiment proving the particle behavior of light is what got Einstein his Nobel prize 2,000 years later.
From this foundation Leucretius claimed that the sun, giving off light, was not an infinite resource and would one day itself die. This was only a few centuries after Anaxagoras was exiled from Athens for claiming the moon was a giant rock reflecting the sun's light.
In a single book are ideas literally over a thousand years before their time (in part due to intentional suppression by the church), and my guess is that until the comment above, you had no idea.
Because a lot of people think evolution was only as old as Darwin.
Some of those ideas may have gone back much further than even the 3rd-1st century CE. The alleged Phonecian creation story from around the time of the Trojan war was about how life began as senseless round creatures that emerged from mud and eventually over time became watchers of the sky.
And the Greeks credited their ideas around atomism not to Democritus but to the Phonecian Mochus of Sidon from around the time of the Trojan war.
But because any sources from back then haven't survived, we tend to credit it to the later sources we can reasonably back up.
Yet the only reason we know that these ideas were around in the 1st century BCE is because the secretary of the Pope right before the Renaissance went around to monasteries bribing guards to smuggle out texts. The only copy of the book about evolution from antiquity was being eaten by worms before it was saved (there's a Pulitzer winning book about its rediscovery and influence on the scientific revolution during the Renaissance called The Swerve).
But most people today have no idea that these ideas go back that far.
And I think that's a shame.
Evolution is kind of a big deal and pretty relevant to our lives.
And the masses collectively forgetting those that came earlier on is a bit like those maggots having been successful in eating away at the legacy of history. Or more accurately, like the church having been successful in denying humanity its own history of innovation and brilliance, let alone having successfully suppressed that knowledge for over a millennia.
In other words, I think you're being ridiculously over-generous in your interpretation of ancient knowledge.
If it were in fact the case that the ancients had any real notion of Darwinian theory, I think they would have stated it in unequivocal terms, as they did with so many other Platonic and/or Aristotlean concepts.
Vaguely suggestive biblical lines interpreted as somehow suggesting an understanding of Darwinian theory strikes me as wishful thinking.
In the beginning, there were many freaks. Earth undertook Experiments - bizarrely put together, weird of look Hermaphrodites, partaking of both sexes, but neither; some Bereft of feet, or orphaned of their hands, and others dumb, Being devoid of mouth; and others yet, with no eyes, blind.
Some had their limbs stuck to the body, tightly in a bind, And couldn't do anything, or move, and so could not evade Harm, or forage for bare necessities. And the Earth made Other kinds of monsters too, but in vain, since with each, Nature frowned upon their growth; they were not able to reach The flowering of adulthood, nor find food on which to feed, Nor be joined in the act of Venus.
For all creatures need many different things, we realize, to multiply And to forge out the links of generations: a supply Of food, first, and a means for the engendering seed to flow Throughout the body and out of the lax limbs; and also so The female and the male can mate, a means they can employ In order to impart and to receive their mutual joy.
Then, many kinds of creatures must have vanished with no trace Because they could not reproduce or hammer out their race. For any beast you look upon that drinks life-giving air, Has either wits, or bravery, or fleetness of foot to spare, Ensuring its survival from its genesis to now."
Leucretius, De Rerum Natura book 5 lines 837-859 (50 BCE)