drawn from an patient on 4 August – just hours before he’d
allegedly injected Trahan – and the procedure hadn’t been recorded
in the usual way. However, Schmidt denied visiting her and giving
her the injection.[1]
Perhaps the virus itself could provide a clue about what had
happened? At the time, it was already common to use DNA testing
to match suspects to crime scenes. However, the task was trickier in
this case. Viruses like evolve relatively quickly, so the virus found
in Trahan’s blood wouldn’t necessarily be the same as the one in the
blood that infected her. Faced with a charge of attempted second-
degree murder, Schmidt argued that the virus that infected
Trahan was too different to the original patient’s virus; it just wasn’t
plausible that this had been the source of her infection. Given all the
other evidence pointing to Schmidt, the prosecution disagreed. They
just needed a way to show it.
O 20 1837, passed down the royal family
tree, from William IV to Victoria. Meanwhile, a short walk away in
Soho, a young biologist was also thinking about family trees, albeit
on a much grander scale. Back in England after his five-year voyage
on HMS Beagle, Charles Darwin would end up outlining his theories
in a new leather-bound notebook. To help clarify his thinking, he
sketched out a simplified diagram of a ‘tree of life’. The idea was that
the branches indicated the evolutionary relationships between
different species. Just like a family tree, Darwin suggested that
closely related organisms would be closer to each other, while
distinct species would be much further away. Tracing each of the
branches would lead to a shared root: a single common ancestor.