On the mating habits of the orb-weaving spider:
These spiders are a bit unusual: females have two receptacles for storing sperm, and males have two sperm-delivery devices, called palps. Ordinarily the female will only allow the male to insert one palp at a time, but sometimes a male manages to force a copulation with a juvenile female, during which he inserts both of his palps into the female’s separate sperm-storage organs. If the male succeeds, something strange happens to him: his heart spontaneously stops beating and he dies in flagrante. This may be the ultimate mate-guarding tactic: because the male’s copulatory organs are inflated, it is harder for the female (or any other male) to dislodge the dead male, meaning that his lifeless body acts as a very effective mating plug. In species where males aren’t prepared to go to such great lengths to ensure that they sire the offspring, then the uncertainty over whether the offspring are definitely his acts as a powerful evolutionary disincentive to provide costly parental care for them.
Excellent write-up. Thanks, Elizabeth.
I’m a software engineer at a company that implements a “20%”. Every couple of months, we have a one (sometimes two) week sprint for the 20%. As you’ve pointed out, it works out to be less than 20%, and many engineers choose to keep working on their primary projects to catch up on delivery dates.
In the weeks leading up to the 20% sprint, we create a collaborative table in which engineers propose ideas and pitch those ideas in a meeting on the Monday morning of the sprint. Proposals fall into two categories:
Reducing technical debt. E.g. deprecating the usage of an old library.
Prototyping a new idea. E.g. trying out the performance of a new library.
I find the 20% sprints very valuable. A lot of the time, there is work I would like to be done that doesn’t fit well within “normal” priorities. I believe such work to be valuable based on my experience and knowledge. However, it doesn’t have sufficient visibility from the perspectives of the higher levels. Therefore, this sort of work would never make its way into our everyday work without the 20% sprint.