Also, the overall chance of pregnancy with unprotected sex involving a man and a woman of childbearing age is 1 in 4. So, would you engage in such sex knowing that there was a 1 in 40 chance it would lead directly to your own death? (Or your partners? Bees be Krayton!)
I wonder if that's where some of our cognitive biases around risk come from? It benefits our genes that we're cavalier about certain kinds of risk.
1 in 20 (~50 in 1000) in the UK until 1940/1950. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1633559/
and lots of interesting reading here: https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1...
Also unprotected sex does not necessarily equal procreative sex, which I realize is a somewhat controversial statement, but nonetheless true.
[0] https://www.plannedparenthood.org/learn/birth-control/withdr... (there's no fragment, it's under the effectiveness section of the accordion)
[1] https://www.plannedparenthood.org/learn/birth-control/condom...
I knew that when I posted it. When I posted it, I thought I had clearly indicated it, but looking at it again, that must have been forgotten before it could be enacted. My intention was to play with the two wildly inaccurate figures together.