Mutations shrink unwanted penis growth in Dogwhelks
Yes, this is a boatish story, albeit a Saturday morning one. It's about antifouling. Antifouling is the stuff we paint on our hulls to prevent (or rather discourage) marine growth. A few decades ago the active ingredient was TBT. Leeching of TBT into the water had an unfortunate side effect; it made female dogwhelks develop a penis. These penises were quite big and blocked the vulva, preventing the lady dogwhelks from releasing their eggs.
We all grumbled a bit when TBT was banned because the replacement wasn't as effective. Many boaters swear by adding chilli powder or powdered copper to their antifouling. Others like Raedwald just put up with a few more barnacles and a slimier hull.
Anyhow, around ten years ago a mutation termed 'Dumpton's Syndrome' began to appear; it shrunk the unwanted penises to a size where they no longer blocked the eggs. Good news for lady Dogwhelks. Now these mutated Dogwhelks make up to 50% of the population in some areas and numbers are recovering well. Brilliant how nature adapts.
Right, off to the boat.