Following the Path of Discovery
Repeat Famous Experiments and Inventions
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Under the constant struggle to exist, inferior organisms are more likely to die before they can reproduce. On average, superior living things with useful traits are more likely to survive and reproduce and thus to pass on their helpful features. As a result, the next generation changes slightly, the struggle for survival goes on among the descendants and the process is repeated. In other words, the struggle for existence selects organisms with helpful variations but makes others die out.
Another useful definition of evolution: A gradual development, from a less adaptable to a more adaptable form through the process of natural selection.
Darwin outlined his theory in his book On the Origin of Species by Means of Natural Selection in 1859 which was met with ridicule, antagonism and skepticism before it was accepted.
Less known are Darwin's botany experiments, especially with orchids.
In 1862 Darwin showed that orchid's beauty was not “designed” by God to please humans but honed by natural selection to attract insect cross-pollinators.
But why the importance of cross-pollination? Darwin's botanical work was always related to his evolutionary mechanism. He believed that cross-pollinated plants would produce fitter offspring than self-pollinators, and he used considerable ingenuity in conducting thousands of crossings to prove the point.
Darwin published his results in a few books:
The Various Contrivances by which British and Foreign Orchids are Fertilised by Insects (1862)
The Effects of Cross and Self Fertilization in the Vegetable Kingdom (1876)
The Different Forms of Flowers on Plants of the Same Species (1877)
More resources about Darwin’s experiments with orchids:
Charles Darwin - Botany Online, University of Hamburg
Darwin Correspondence Project (Vol. 10) - University Library, Cambridge
Darwin Correspondence Project (Vol. 11) - University Library, Cambridge
On the various contrivances by which British and foreign orchids are fertilised by insects (Chap. VI)
Reasonings February 2002
Darwin from Orchids to Variation - Wikipedia
Ironically named 'Star of Bethlehem' orchid supports Darwin's theory of evolution - gizmodo.com.au
Darwin got some support for his cross-pollination idea from modern science evidence:
Orchids Profit From False Advertising - James Owen, National Geographic News
Pollen Carryover, Geitonogamy, And The Evolution Of Deceptive Pollination Systems In Orchids
The effects of nectar addition on pollen removal and geitonogamy in the non-rewarding orchid Anacamptis Morio
Darwin also studied insectivorous plants, climbing plants, and the response of plants to gravity and light (sunlight, he thought, activated something in the shoot tip, an idea that guided future work on growth hormones in plants).
A few good general links about Darwin and evolution:
Darwin - American Museum of Natural History
Evolution Website - BBC
The Complete Work of Charles Darwin Online - John van Wyhe
Evolution - PBS
Do You Believe in Evolution? - Bob Riggins
Rocky Road: Charles Darwin - Strange Science
Robert Fitzroy: The Captain of the HMS Beagle
Darwin Jokes and Evolution - Jokes and Science
Evolution Science Fair Projects and Experiments
How to grow orchids
Orchid Growing Instructions & Background Information