Today's Google Doodle reminds us that without the meticulous work of Gregor Mendel, evolutionary biology would make no sense.
You might remember from high school biology class that Mendel mucked about with peas, and that he came up with the concept of dominant and recessive traits. But why, exactly, is any of this important in 2011?
Because without Mendel's contributions, Charles Darwin's theory of evolution would make no sense. In his 1859 book "The Origin of Species," Darwin postulated that species evolve by means of mutation and natural selection. For example, an antelope-like creature with a slightly longer neck will be able to dine on leaves that are unreachable by her peers. This advantage will make her more likely to survive into adulthood and to have more offspring, who are themselves more likely to have inherited their mother's longer neck. Eventually, over thousands of generations, the trait for longer necks spreads through the population, and they gradually become giraffes.
So far, so good. But in Darwin's time, nobody understood how traits were inherited. The dominant belief back then was that inherited traits blended together. Under this model, the daughter of a long-necked mother and a normal-necked father will be only somewhat longish necked. And when that somewhat-longish-necked daughter mates with a normal-necked male, their offspring will be only a little bit long-necked, and so on through the generations until the trait is diluted away.