150th anniversary of “On The Origin of Species”
This month is the 150th anniversary of Charles Darwin’s On the Origin of Species, perhaps the greatest scientific and social publication in history. Many years ago I purchased a paperback copy of Darwin’s book, a Dover publication as I recall, and read it for the first time, though not from cover to cover. At that time, reading it more than a 125 years or so after it was first published, introduced me to the arguments, examples and logic that Darwin used to make his case: the genius of his insights and the power of his observations are not subtle in the book. But then as now, there was little doubt or argument that evolution was the only rational way to interpret biological variance in species and the principle of natural selection seemed like a sensible way for nature to take advantage of genetic mutations, the majority of which probably give a disservice to the propagation of the species. But at the period of my reading and even more so today, evolution had become a proven fact, not a theory, a result of an expansive knowledge of biology, molecular biology and genetics, coupled with increasing clarity from the fossil record, including that of our own Hominidae and Hominina history, which, for human ancestors (Hominina), now goes back more than 4 million years. We know more about evolution than we do about the structure of the atom and each new piece we find in the puzzle, such as the ever-expanding Hominina fossil record, gives us an increasingly broad insight of our ancestors’ culture and behavior, all achieved through slow changes that reveal a story about a species that started to walk erect before it developed its large brain. But at the time that Darwin published his book, there was virtually no knowledge of genetics and only a very primitive grasp of the fossil record that supported such a sweeping interpretation of species origins and connectivity. Darwin did however acquire fossils during his trip to the Galapagos Islands beginning in 1831. He made his case for evolution based on the animals that he retrieved for study, including many birds, and the evolutionary-like changes that man had created through domestication of certain species, particularly dogs. Though Darwin had no knowledge that the code for reproduction was within our DNA, which would not be identified until well into the next century, and he did not have knowledge of Gregor Mendel’s work on plant genetics and the nature of inheritability, his introduction of natural selection as the key to adapting mutational change for improved chances of species survival, was the most insightful feature of his argument. Darwin’s genius was in recognizing that a vast change in species could be achieved over time, through minute, advantageous and heritable traits that would initially appear to be small. As one example, he used the evolution of the eye from invertebrates to mammals as an illustration of the differences in optical qualities that could be achieved through natural selection, advantageous changes and a whole lot of time. The time required for these changes remains incomprehensible for humans to absorb.
Print This Post
