But that kind of omits the fact that in our modern day and age, the elderly have a lot more technical help available. For Darwin, it was a decision of leaving his family behind to go on a months-long trip. Nowadays, it'd be a 6 hour flight and you can call your friends while you're on vacation.
So the risk/reward tradeoff has massively changed since Darwin's times.
The section on Darwin was an eyebrow raiser. It makes sense to include someone like Darwin (very interesting and well known), but he's not a great example to compare to "normal" people (like the couple mentioned in the opening paragraph).
A 50 year old in the 1800s whose job was catching a ship to the other side of the planet is a little different when compared to a factory worker, software engineer, doctor, etc.
Also, what the fuck is this off-hand remark:
> Unfortunately, Mendel’s work was published in an obscure academic journal and Darwin never saw it—and in any case, Darwin did not have the mathematical ability to understand it.
This part is true. Not sure about Darwin's mathematical knowledge.
> and in any case, Darwin did not have the mathematical ability to understand it.