Introducing DNA to Darwin

Charles Darwin knew almost nothing about genetics. Many biologists of his time thought that the characteristics of parents were blended in the offspring. The problem with this, which Darwin appreciated, was that after a few generations any variation would be blended away, giving natural selection nothing to work on. Read More…

Darwin devoted much thought to this issue but never found a satisfactory answer.

It wasn’t until the late 1940s that scientists generally agreed how their increasing understanding of genetics was consistent with natural selection and evolution. This was called the ‘modern synthesis’ and today it forms the basis of evolutionary biology. One of the creators of the modern synthesis, Theodosius Dobzhansky, memorably said that:

“… nothing in biology makes sense except in the light of evolution”.

Evolution is indeed the central unifying concept in biology, but researchers in many fields including molecular and cellular biology, developmental biology, microbiology and neuroscience have only recently begun to think seriously in terms of evolution. The chief reason for this shift in thinking is the growing list of organisms — from bacteria to primates — with sequenced genomes, plus the development of increasingly sophisticated ways of interpreting DNA and protein sequences.

Francis Crick, the co-discoverer of the structure of DNA, quickly grasped the significance of DNA to evolution, however. In June 1989, long before any genomes had been sequenced, he wrote:

“ I think the most significant aspect of DNA is the support it gives evolution by natural selection”.

Charles Darwin didn’t know about DNA, but in 1857 he wrote to his friend and colleague Thomas Henry Huxley, saying:

“ The time will come, I believe, though I shall not live to see it, when we shall have fairly true genealogical trees of each great kingdom of Nature”.

Darwin would no doubt have been delighted to see how modern genetics supports and confirms many of his ideas, and provides evidence not only for what has happened in the course of evolution, but precisely how living things evolve. DNA is the forensic evidence for evolution.

Case Studies

DNA to Darwin allows 16–19 year-old school students to explore the molecular evidence for evolution through practical bioinformatics activities that use data analysis tools and molecular data.

Each of the activities on this web site centres around an engaging story from recent research in molecular genetics encompassing microbiology, plant and animal biology and human evolution.