Bioturbation

A major re-evaluation of soil formation and the role of biota commenced in the 1980s, as soil-geomorphologists began to re-evaluate Charles Darwin's and Nathaniel Shaler's early ideas on the role of bioturbation in soil formation. There is now ample evidence to support Darwin's conclusions, and in many areas biota that burrow in soil are major agents of pedogenesis.

Darwin, charles robert

Darwin was born on February 12, 1809 on the same day that Abraham Lincoln was born in Kentucky. He was the son of a doctor and the grandson of the poet-doctor, Erasmus Darwin.

Darwin showed no particular promise in his youth. At first he studied medicine, but found that unlike his father and grandfather he had no ability for it. He thought next that he would make a carrier in the church but found he had no ability for that either. However, he had made natural history his hobby after reading Humboldt and had grown gradually more interested in the subject during his stay in Cambridge. This was his road to fame. His first scientific work was taking part in a geologic expedition led by Sedwick.

The ship Beagle was about to set out for a voyage of scientific exploration in 1831 and Darwin took part in the voyage as the ship's naturalist. Off he went on a five-year cruise around the world, the most important voyage in the history of geology.

During the voyage of the Beagle, Darwin watched how species changed, little by little, as the ship moved down the coast of South America. Most important of all were his observations during a five-week stay of the animal life of the Galapagos Islands, a group of a dozen or so islands about six hundred and fifty miles off the coast of Ecuador. What Darwin mainly studied there was a group of birds now called "Darwin's finches".

These finches were closely similar in many ways but were divided into at least fourteen species. Not one of these species lived on the nearby continent, or, as far as was known, anywhere else in the world.

But what would cause those evolutionary changes?

Darwin returned to England in 1836 with no answer. He wrote several books on the voyage and the observations he had made. The first of these now usually known as A Naturalist's Voyage on the Beagle, was a great success and made him famous.

Soon he joined the Geological Society of London and was its secretary. There he met the well-known naturalist Lyell and discussed the problem of evolution with him. These discussions helped Darwin to understand that creatures would adapt themselves to different ways of life under the stress of evironmental pressure. Thus nature would select one group over another and by such "natural selection" life would branch out into infinite variety, more efficient groups always replacing less efficient ones in particular environmental conditions.

Darwin used to classify and collect his information endlessly. In 1844 he started a book on the subject, but continued to collect his examples and in 1858 he was still working at it.

His friends knew what he was doing and Lyell in particular was constantly telling him to publish his book, for evolutionary ideas were in the air, and he was right. Another naturalist, Wallace, wrote a paper, embodying Darwin's ideas almost to a letter and then sent a copy to none other than Darwin himself. When Darwin received the manuscript he was thunderstruck". However, he was an ideal scientist. He didn't publish quickly to be the first in discovering the idea of evolution. He passed on Wallace's work to other important scientists and offered to collaborate with Wallace on papers summarizing their mutual conclusions. This was done. The work of both men appeared in the Journal of the Linnaean Society in 1858 and the next year Darwin published his book, the full title of which is "On the Origin of Species by Means of Natural Selection". It is usually known as "The Origin of Species".

The learned world was waiting for the book. Only 1,250 copies were printed and everyone was sold on the first day of publication. It went through printing after printing, and it is still being reprinted now, a century later. It is one of the classics of science.

Darwin died in 1882 and was buried among England's heroes and near Newton and Faradey, as well as his friend Lyell.