In case you didn't know...
Today is the 200th birthday of Charles Darwin. Best known for formulating the theory of evolution by means of Natural Selection (which explains how the peacock got its wings), less well known for coming up with the theory of Sexual Selection (which explains how the peacock got its tail), and totally ignored for explaining how coral reefs formed.
What is remarkable about Darwin's theory is that the:
"...whole theory was thought out on the west coast of S. America before I had seen a true coral reef."
"But it should be observed that I had during the two previous years been incessantly attending to the effects on the shores of S. America of the intermittent elevation of the land, together with the denudation and the deposition of sediment. This necessarily led me to reflect much on the effects of subsidence, and it was easy to replace in imagination the continued deposition of sediment by the upward growth of coral."
Darwin observed volcanic islands in the Atlantic, and the second of his books on the geology observed on the voyage of the Beagle (Volcanic Islands, published in 1844) discusses the evidence for crustal uplift as caused by volcanic activity, and corresponding subsidence after the volcano became extinct. On the coast of South America he saw (and when caught in an earthquake, felt) the evidence for large-scale, and long-term movements of the Erth's crust. Having worked out how coral reef ought to form he was in a position to study real reefs to confirm or refute this hypothesis.
Gathering data from soundings taken by the Beagle's Captain Fitzroy, and from a wide range of other sources Darwin confirmed that the "polypifers" that created coral reefs were shallow water organisms. Darwin was unaware of the diversity of deep-water organisms, nor of the range of organisms that contribute to reef formation- had he been, he would have needed to qualify these observations. Rosen (1982) notes that this lack of knowledge probably helped Darwin to formulate the theory.
Darwin also considered the ecology of reefs, noting that the most exposed parts of the reef are mostly home to massive corals and red algae, and this was the area of most active reef growth. Once a reef has reached sea-level it then grows outwards. In the 130-odd years these basic observations have not been seriously challenged.
It was his work on coral reefs that earnt him scientific credibility, and made him a member of the scientific establishment. So by all means raise a toast to one of Natural Selection's founding fathers, but don't forget he was more than just a biologist. He was also a geologist, oceanographer, biogeographer and ecologist, long before many of these disciplines were recongised.
What is remarkable about Darwin's theory is that the:
"...whole theory was thought out on the west coast of S. America before I had seen a true coral reef."
"But it should be observed that I had during the two previous years been incessantly attending to the effects on the shores of S. America of the intermittent elevation of the land, together with the denudation and the deposition of sediment. This necessarily led me to reflect much on the effects of subsidence, and it was easy to replace in imagination the continued deposition of sediment by the upward growth of coral."
Darwin observed volcanic islands in the Atlantic, and the second of his books on the geology observed on the voyage of the Beagle (Volcanic Islands, published in 1844) discusses the evidence for crustal uplift as caused by volcanic activity, and corresponding subsidence after the volcano became extinct. On the coast of South America he saw (and when caught in an earthquake, felt) the evidence for large-scale, and long-term movements of the Erth's crust. Having worked out how coral reef ought to form he was in a position to study real reefs to confirm or refute this hypothesis.
Gathering data from soundings taken by the Beagle's Captain Fitzroy, and from a wide range of other sources Darwin confirmed that the "polypifers" that created coral reefs were shallow water organisms. Darwin was unaware of the diversity of deep-water organisms, nor of the range of organisms that contribute to reef formation- had he been, he would have needed to qualify these observations. Rosen (1982) notes that this lack of knowledge probably helped Darwin to formulate the theory.
Darwin also considered the ecology of reefs, noting that the most exposed parts of the reef are mostly home to massive corals and red algae, and this was the area of most active reef growth. Once a reef has reached sea-level it then grows outwards. In the 130-odd years these basic observations have not been seriously challenged.
It was his work on coral reefs that earnt him scientific credibility, and made him a member of the scientific establishment. So by all means raise a toast to one of Natural Selection's founding fathers, but don't forget he was more than just a biologist. He was also a geologist, oceanographer, biogeographer and ecologist, long before many of these disciplines were recongised.