The Science of DNA Evidence
October 14, 2011 Leave a comment
Wired has an informative article from Ars Technica on the science behind the DNA evidence used in court, in the context of the prominent Amanda Knox case – a young American originally convicted of murder in Italy, then recently released. There are two main points: first, the DNA evidence they had against Amanda Knox was weak and wouldn’t have been considered in a U.S. court. Second is the explanation of how DNA evidence is gathered, analyzed and interpreted.
A very brief summary of the science would be that everyone has short, repeated sequences in their DNA that don’t code for anything. These are repeated to different degrees in different individuals. Seeing how many times any of these sequences repeats, across a large number of types of sequences, allows you to distinguish different individuals’ DNA.
The article goes more in-depth into the science, and links to another Ars Technica article with even more specific science behind DNA sequencing and replication, so if you’re interested at all, I encourage you to check it out. If you have any questions afterwards, I’d be happy to try to address them.