This is Part 14 of a series of approximately sixty posts that outline evidence, support, and explanations for evolution. Receive updates and notification of all posts from dennismitton.com by selecting the Email Membership button on the sidebar of any page. Thanks!
Go here for the previous post.
Copyright Dennis Mitton
Darwin wasn’t the first to notice and think about the great diversity of life on the planet. Plato argued that everything – animals, ideas, colors – are all representations of perfect heavenly forms. There is a perfect form for ‘blue’ and all blues have something of that perfect form in them. All snakes have something of the perfect form for ‘snake’ in them. This Essentialism, that everything has a sense of the essential nature of the perfect in them, is a basis of Christianity and of modern creationism. Other ancient philosophers argued for a diverse mix of answers. Many believed that nature revealed the necessity of a creator. Others argued that the first animals emerged spontaneously from the pre-historical earth. Some believed that animals cycled through extinction and spontaneous generation continuously. Without a framework and understanding of robust scientific investigation, there were little means to explore the question in other than a philosophical way.
The crown of creation philosophy, still prevalent today, is Natural Theology which seeks to prove God’s existence and to discover his character through nature. It recognizes God as creator and sustainer and upholds the Christian Bible as its textbook. Modern eyes see the philosophy as resolutely anti-scientific: proponents begin with ‘truth’ and then search for evidence. Those brave souls who, with the dawning of the age of science, turned this on its head – drawing unbiased conclusions only after examining evidence – often found themselves in trouble with the Church and other scientists. This was the intellectual climate as the world turned to the nineteenth century. This was the world of Lamarck (Part 12) and Lyell (Part 7) and of Linnaeus and of an experienced explorer and now gentleman lounger and thinker named Charles Darwin.
It was while on board the survey ship HMS Beagle and lolling away long hours reading Lyell’s Principles of Geology that Darwin’s nascent ideas of change by natural selection took shape. He wondered about the plants and animals he saw – why were they different from those in Europe? On the Galapagos Islands, he noticed that similar birds, finches, separated by geography, appeared different. Why? And why were finches at home in England different from those in South American? Why do creatures go extinct? These questions never left the young Darwin. It wasn’t until several years later, at home and writing up his observations from the Beagle, that he would fully realize and describe his nascent ideas, now called evolution.
Rates of Reproduction
Though not a trained scientist (he studied medicine for a time but hated the sight of blood), Darwin was a masterful observer of nature. He saw that for all organisms and for all populations and parents, some offspring are better suited for their environment than others. So in a population of birds that crack nuts for food, some birds – those with stronger and more robust beaks – will be better able to crack nuts and thus better able to survive to mate and pass their traits on to the population. The differential rate of reproductive success is Darwin’s great idea in the smallest of nutshells. The two keys are differences in offspring and different environments. He further came to see all organisms on earth as related in a tree-shaped pattern with each leaf and branch connected to those nearby and all life intertwined the further down the trunk one travels. This differed in revolutionary ways from the then-current ideas of these relationships as a ladder rising in compartmented complexity from bacteria to mankind. Darwin believed his science to be sound but knew his tree of life was revolutionary in resting man on a branch just like any other organism. His man was not the pinnacle, not the top rung of the ladder, not the headpiece of God’s special creation, but just another animal in the tree. His angst over the issue was prescient and reverberates today in every creationist book and lampoon against categorizing men and women as another animal.
At the behest of friends and in response to correspondence from Alfred Wallace who had developed ideas very similar to Darwin, in 1858 Darwin’s ideas were introduced by friends to the London Linnean Society. The next year he published his seminal On The Origin Of Species By Means Of Natural Selection, now considered to be the most influential academic book of all time. Origin met a mixed reception. Some scientists grasped the importance of the work immediately. Others dipped their toe in lightly, understanding the explanation of reproduction and differential selection but rejecting the idea that man is just another animal. Darwin argued with Lyell about this very point for decades. Many, as was expected, rejected the idea wholesale as did much of the general population.
In the next post I will look at the cultural reaction to the most influential academic book and bedrock idea of biology. Be sure to sign up in the side-bar for updates!
Darwin Online – Wonderful website with almost everything the old man wrote – for free! This is exactly what the internet was made for.
To see all of the Evolution Explained series, go here.
Click here to return Home.
If you enjoy the post and want to receive more of my Evolution in Sixty Posts series…of if you enjoy reading book reviews, hack philosophy, or posts about longevity or health, then please sign up for email updates at the top right of any page.