A joke.<p>How many geneticist does it take to change a lightbulb?<p>We’ve found 12,000 switches hidden around the house. Some of them turn
this lightbulb on, some of them don’t; some of them only work
sometimes; and some of them work sometimes, but twenty years after you
flick them. Some of the switches only work, sometimes, twenty years
later, if one of the other switches is flicked too (and at the right
time). In any case the wiring’s rusty, everything’s completely
different in the house next door, and by the way there are lots of
people selling spare bulbs who tell lies about houses, switches, and
fingers.<p>We can change the lightbulb, but I’m not sure that’ll stop you dying
from cancer in this metaphor.