In commemoration of Charles Darwin's birthday on February 12, we will be reading again about evolution. Much if it will have been said before, many times. Here I am going to try to take a less familiar line and show how Darwinian evolution by natural selection has roots in the atomism of ancient Greece.
In the fifth century BCE, the Greek philosophers Leucippus and Democritus proposed a simple model of reality: all that exists are material atoms and the void. Atoms were defined as elementary objects that cannot be further subdivided. The universe composed of atoms and void is infinite in extent and eternal in time. Events happen by chance, with no ultimate purpose. Any gods that may exist play no role in the world or in human life.
Atomism contradicted the predominant philosophical teachings of the age, notably those of Aristotle, Plato, and the Stoics. However, it became the basis of the philosophical school established by Aristotle's contemporary, Epicurus. Later, around the time of Julius Caesar, the Roman Lucretius composed an epic poem De rerum natura (On the Nature of Things) in Latin that immortalized the teachings of Epicurus and the atomists who preceded him. The atomic model contributed to the significant scientific progress that occurred in Greece and Rome during those centuries.
However, most of this progress, along with atheistic atomism, was suppressed when Christianity took over the Roman Empire in the fourth century CE, initiating the thousand-year period known as the Dark Ages. Only by sheer luck did a copy of De rerum natura survive. When it was discovered during the Renaissance, it helped encourage the scientific revolution that followed. The atomic picture of particles moving around and colliding with one another became the essence of Newtonian mechanics.
In the nineteenth century, atoms were identified with the chemical elements. In the early twentieth century, these "chemical atoms" were separated into more fundamental constituents. By the 1970s, these constituents were reduced further to the quarks, leptons, and bosons of the standard model of elementary particles and forces. The ultimate triumph of atomism, and the standard model, came in July, 2012 when it was announced that the Higgs boson, a particle predicted forty-eight years earlier as the source of the masses of elementary particles, had been confirmed by two independent experiments involving thousands of scientists.
The nature of matter was not the only insight of the first atomists that has found support in modern science. Quantum mechanics and Darwinian evolution before it established the central role of chance in the world. Furthermore, modern cosmology strongly indicates an eternal "multiverse" in which our universe just one of perhaps and unlimited number of others.
In none of this do we find any need to introduce immaterial elements into our models to describe observations. The atheism of ancient atomism is confirmed by the science of today.
I expect to get disagreement from dualists who will say that because we still don't have a consensus material explanation of consciousness, the door is still open for there to be a nonmaterial component to the human mind. However, models that introduce immaterial elements into the human cognitive process have failed to produce any supportive evidence comparable to materialistic brain science. So far, brain science, which is very much based on atomism, has been making steady progress in explaining the features of consciousness. Dualism has made none.
Now, here's what this has to do with Darwin: Lucretius anticipated evolution by natural selection. He talks about how, in the beginning, there were many freaks with various deformities that made them unable to reproduce or forage for food and so their species died off. You will get objections from some scholars that this was not really evolution, so I will just provide the following excerpt:
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.
(Translation by A. E. Stallings)