Inventing evolution was hard. No one but the ancient Greeks and a scant few of their intellectual descendants made any progress on explaining where life came from till Darwin. Before that, the closest we really got to a modern understanding of evolution was Epicurus, and it took nearly two thousand years to make theory that was wholly better than his.
We know that because that’s what the writings of the ancients implied. And I’ll show you that by comparing their writings on the origins of life to (roughly) what Darwin knew. I’m not going to require a full mechanistic explanation. Even just a conceptual understanding of that species are formed by an ongoing selection on variation that is inherited and generated anew each generation through reproduction would be enough, along with a realization that life originated from raw matter.
Anaximander (c. 610–546 BCE): Anaximander had the idea that living beings differed in the past. Humans are frail when young, so the first humans could not have been unprotected babes. Instead, they developed inside fish-like creatures until they were capable of fending for themselves. The 3rd-century Roman writer Censorinus records:
“Anaximander of Miletus considered that from warmed up water and earth emerged either fish or entirely fishlike animals. Inside these animals, men took form and embryos were held prisoners until puberty; only then, after these animals burst open, could men and women come out, now able to feed themselves.”
Empedocles: Empedocles understood that species are selected for fitness, and there must be variation for this fitness to act over. He believed species are the result of a primordial, random combination of heads, bodies, eyes and limbs. Living beings changed and only those combinations which were fit for life survived and reproduced. From his poem On Nature:
“Here sprang up many faces without necks, arms wandered without shoulders, unattached, and eyes strayed alone, in need of foreheads. (Fragment B57)
Many creatures were born with faces and breasts on both sides, man-faced ox-progeny, while others again sprang forth as ox-headed offspring of man, creatures compounded partly of male, partly of the nature of female, and fitted with shadowy parts. (Fragment B59/B61)”
But he couldn’t conceptualize small enough variations or understand that variation came from sexual recombination and mutation. And where life came from went wholly unexplained.
Epicurus (341–270 BCE): Epicurus gestured at an explanation for the origins of life. Life arose from the random combinations of atoms. Those forms best suited to survival reproduced themselves.
“Nothing is created out of that which does not exist: if it were, everything would be created out of everything with no need of seeds.”
Given that we still aren’t sure how life originated from random combinations of atoms, I’d say he did remarkably well.
Lucretius (c. 99–55 BCE): Lucretius, unlike the rest of the ancient innovators on the origins of species, was not a Greek. Instead he was a Roman, and an intellectual descendant of Epicurus. He thought the young earth was so fertile that creatures spontaneously arose from it in random forms. Most forms of life could not eat, or reproduce, and so died out.
“Many monsters too the earth at that time essayed to produce, things coming up with strange face and limbs... some things deprived of feet, others again destitute of hands, others too proving dumb without mouth, or blind without eyes... Every other monster and portent of this kind she would produce, but all in vain, since nature set a ban on their increase and they could not reach the coveted flower of age nor find food nor be united in marriage.” (De Rerum Natura Book 5)
He emphasized the need to reproduce as core to a species thriving. Beyond that, those which had some strength, or cunning or utility to mankind would be better suited to life. So, there’s variety, selection, and an emphasis on reproduction.
“For we see that many conditions must meet together in things in order that they may beget and continue their kinds.”
However, Lucretius missed that variety is generated by reproduction and that selection is ongoing rather than an event which only occurred in the distant past. And yes, we can’t assume he understood that, because other early proponents of the development of species explicitly claimed that wasn’t the case!
Saint Augustine (354–430 CE): He argued that species of animal and plants, not individuals, emerge from water and earth and “develop in time... each according to its nature” — De Genesi ad Litteram (On The Literal Interpretation of Genesis). God set the potentiality of development of species, and likewise for man. I.e. species “grow up” according to some fixed schema. So there’s potential for change, but no selection over variation, no explanation of variation, life originating from raw matter etc. Just changing species.
Inventing evolution was hard. No one but the ancient Greeks and a scant few of their intellectual descendants made any progress on explaining where life came from till Darwin. Before that, the closest we really got to a modern understanding of evolution was Epicurus, and it took nearly two thousand years to make theory that was wholly better than his.
We know that because that’s what the writings of the ancients implied. And I’ll show you that by comparing their writings on the origins of life to (roughly) what Darwin knew. I’m not going to require a full mechanistic explanation. Even just a conceptual understanding of that species are formed by an ongoing selection on variation that is inherited and generated anew each generation through reproduction would be enough, along with a realization that life originated from raw matter.
Anaximander (c. 610–546 BCE): Anaximander had the idea that living beings differed in the past. Humans are frail when young, so the first humans could not have been unprotected babes. Instead, they developed inside fish-like creatures until they were capable of fending for themselves. The 3rd-century Roman writer Censorinus records:
“Anaximander of Miletus considered that from warmed up water and earth emerged either fish or entirely fishlike animals. Inside these animals, men took form and embryos were held prisoners until puberty; only then, after these animals burst open, could men and women come out, now able to feed themselves.”
Empedocles: Empedocles understood that species are selected for fitness, and there must be variation for this fitness to act over. He believed species are the result of a primordial, random combination of heads, bodies, eyes and limbs. Living beings changed and only those combinations which were fit for life survived and reproduced. From his poem On Nature:
“Here sprang up many faces without necks, arms wandered without shoulders, unattached, and eyes strayed alone, in need of foreheads. (Fragment B57)
Many creatures were born with faces and breasts on both sides, man-faced ox-progeny, while others again sprang forth as ox-headed offspring of man, creatures compounded partly of male, partly of the nature of female, and fitted with shadowy parts. (Fragment B59/B61)”
But he couldn’t conceptualize small enough variations or understand that variation came from sexual recombination and mutation. And where life came from went wholly unexplained.
Epicurus (341–270 BCE): Epicurus gestured at an explanation for the origins of life. Life arose from the random combinations of atoms. Those forms best suited to survival reproduced themselves.
“Nothing is created out of that which does not exist: if it were, everything would be created out of everything with no need of seeds.”
Given that we still aren’t sure how life originated from random combinations of atoms, I’d say he did remarkably well.
Lucretius (c. 99–55 BCE): Lucretius, unlike the rest of the ancient innovators on the origins of species, was not a Greek. Instead he was a Roman, and an intellectual descendant of Epicurus. He thought the young earth was so fertile that creatures spontaneously arose from it in random forms. Most forms of life could not eat, or reproduce, and so died out.
“Many monsters too the earth at that time essayed to produce, things coming up with strange face and limbs... some things deprived of feet, others again destitute of hands, others too proving dumb without mouth, or blind without eyes... Every other monster and portent of this kind she would produce, but all in vain, since nature set a ban on their increase and they could not reach the coveted flower of age nor find food nor be united in marriage.” (De Rerum Natura Book 5)
He emphasized the need to reproduce as core to a species thriving. Beyond that, those which had some strength, or cunning or utility to mankind would be better suited to life. So, there’s variety, selection, and an emphasis on reproduction.
“For we see that many conditions must meet together in things in order that they may beget and continue their kinds.”
However, Lucretius missed that variety is generated by reproduction and that selection is ongoing rather than an event which only occurred in the distant past. And yes, we can’t assume he understood that, because other early proponents of the development of species explicitly claimed that wasn’t the case!
Saint Augustine (354–430 CE): He argued that species of animal and plants, not individuals, emerge from water and earth and “develop in time... each according to its nature” — De Genesi ad Litteram (On The Literal Interpretation of Genesis). God set the potentiality of development of species, and likewise for man. I.e. species “grow up” according to some fixed schema. So there’s potential for change, but no selection over variation, no explanation of variation, life originating from raw matter etc. Just changing species.