Chroniton brings us a story about research into DNA which has shown that free-floating DNA strands are able to seek out similar strands
without the assistance of other chemicals. From Imperial College London:
"The researchers observed the behaviour of fluorescently tagged DNA molecules in a pure solution. They found that DNA molecules with identical patterns of chemical bases were approximately twice as likely to gather together than DNA molecules with different sequences. Understanding the precise mechanism of the primary recognition stage of genetic recombination may shed light on how to avoid or minimise recombination errors in evolution, natural selection and DNA repair. This is important because such errors are believed to cause a number of genetically determined diseases including cancers and some forms of Alzheimer's, as well as contributing to ageing."