Charles Darwin's 200th birthday is today. His masterwork, "On the Origin of Species," published 150 years ago, transformed our understanding of the natural world and of ourselves — and continues to do so. It has become impossible to imagine modern science without it.

Before Darwin, biology was stamp collection — a laundry list of random and disconnected facts. We could explain everything (and at the same time nothing) by saying that things were "just made that way."

Darwin's theory of evolution by natural selection showed us the patterns in, and so made sense out of, all these facts.

Darwin knew that children tend to resemble their parents, and this simple observation was critical to his theory. But exactly how inheritance works remained a mystery that puzzled him all his life. Scientists have since discovered genes, deciphered how they are constructed out of DNA and how these DNA instructions guide the production of cells, tissues and organs, as well as how they determine physical traits from eye color to which diseases we are likely to get.

Now researchers have even decoded the entire DNA sequences, or genomes, of many organisms, including humans. Remarkably, nothing emerged throughout all these discoveries that challenges the fundamentals of Darwin's theory. In all the history of science, few scientific ideas can boast such extraordinary longevity in the face of such an enormous increase in knowledge.

Just as scientific research in physics exploded when Isaac Newton discovered calculus and the laws of motion, Darwin's theory launched an explosion in biological research that continues today at breakneck speed.

In fact, now that we do biology by comparing differences between the entire genomes of, for example, a chimpanzee and a human, evolutionary theory is more central than ever. Discoveries motivated by evolution are increasingly relevant to solving the most pressing of human problems, including the treatment of genetic disease, the control of infectious disease and the sustainability of agricultural production. Evolution is so taken for granted in science today that it can be hard to define where "evolutionary biology" starts and stops. The fossil fuels we rely on are the products of ancient life forms, and geologists choose where to drill based on our knowledge of the ancient evolutionary history of those areas.

Medical researchers know that, every year, influenza virus will have evolved resistance to last year's vaccine, and so do their best to predict evolution and produce an effective new vaccine. Entomologists use evolutionary theory to help farmers use pesticides in a way that prevents insect pests from developing resistance.

From climate change to medicine, the theory of evolution is the glue that holds the disparate facts of biology together.

Darwin opened up our ability to understand the workings of the natural world by applying the scientific method. His theory continues to help us both to understand the glory and wonder of the natural world and to find solutions to the immense biological challenges facing us.

On StarNet: Syndicated columnist George Will and retired teacher Peter Bourque write about the contributions of others marking 200 — Darwin, Lincoln and Poe.

Write to Joanna Masel at