Raymond Beisinger
Our understanding of evolution today stems from the combination of two very different ideas. One came from a monk who studied pea plants in a Moravian monastery in the 1850s. The other came from a Victorian gentleman who spent five years as a naturalist on a voyage around the world, 20 years previously.
Although Gregor Mendel and Charles Darwin were alive at the same time, they never met and Darwin wasn’t aware of Mendel’s work. With hindsight, the union of the two men’s work seems like a marriage made in heaven (or hell, if you’re a creationist). In fact, for many years, it wasn’t obvious that Mendel’s studies of heredity had any relevance to Darwin’s theory of evolution by natural selection. It would take nearly 60 years for this jigsaw to be pieced together and give rise to the “modern synthesis” of evolution, which framed Darwin’s idea in terms of genetics.
How exactly did this new understanding arise? And why did it take so long?
The explanation starts with natural selection itself. According to this, only the fittest – the best adapted to the local environment – survive and breed, and in this way the population as a whole gradually transforms. The idea of evolution was already accepted by many biologists in the mid-19th century, but there was considerable opposition to the notion that it happened by means of natural selection.
The plausibility of this mechanism rests on the assumption that beneficial characteristics are passed more or less intact from one generation to the next. But it was not clear how this might happen.
To explain heredity, Darwin proposed a hypothesis …
