Apropos of Y. pestis (plague) genes being found in a 4000 year old skeleton, @Sylvia Knight was wondering out loud why the sudden catastrophic wave of the disease, the Black Death, in the 13th century.

So I did a bit of reading. There was a fringe theory a couple of decades ago that black death was not bubonic plague. One of the reasons some people thought this is from epidemiology: it spread too fast. Specifically, it travelled around Europe at the speed humans did, not at the speed rats did, suggesting rat fleas were not responsible for primary transmission, as many of us were taught at school.

Turns out that, however, human fleas can also transmit the disease, but they're really shit at it and probably not the culprit.

But body lice, they are like, actually quite good at transmitting it. Apparently coming into contact with a plague corpse 3 days post mortem, if that corpse had body lice, is sufficient to infect you with around 10 bites. Really not many.

Body lice don't live on warm human bodies - it's not comfortable for them. They live in our clothes.

Or rather, they used to. Laundry detergent eradicated them.

But laundry detergent is a 20th century invention, and the plague stopped coming to Europe in the 17th century.

Soap was around before though, a long time before.

Very popular in the Middle East towards the end of the 1st millennium.

Which means, of course, in Christian Europe, it became associated with Islam, and therefore was dubious.

Apparently there was a huge decline in soap use in Europe in the medieval period.

Which, of course, would allow the louse population to flourish.

Racism killed a third of Europe in the 13th century. Silly buggers.

By the way, I know we are increasingly encouraged to cold-wash our clothes these days for environmental reasons, but maybe ... let's not, eh?

Seen a bunch of people sharing this one idea that the Iberian orcas are attacking sailing boats because one of them was previously “traumatised”.

I think it needs to be said that this is a fringe theory and widely regarded by lots of people studying this emergent behaviour as implausible.

For a start, orcas swim at 3 times the speed a sailboat travels at. As far as they’re concerned, they are essentially stationary objects. Secondly, orcas weigh more than sailboats, and if they wanted to sink them, they could, easily, but they aren’t doing that.

What the orcas are doing is biting rudders. The sinkings that have happened have been secondary to that: water ingress caused by damage to the rudder stock.

The leading theory is that this started as hunting practice. The Iberian orcas eat tuna, and they hunt them by biting their fins off so they can’t swim away. Sailboat rudders superficially resemble tuna fins, and so are good practice.

The behaviour started with a few young males about 3-4 years ago. It’s now spread and around 15 of them are doing it. It’s nearly all young males.

It appears that what started out as practice has now become the orca equivalent of that arsehole on TikTok walking into people’s houses: they appear to be doing it because their mates do it, and they think it’s funny.

Sadly inaction by, mostly Spanish authorities is leading to people increasingly taking things into their own hands. Sailboat owners share information on orca locations and are increasingly travelling in convoys, WWII style. Initially putting the boat into reverse on engine seemed to work, but they’ve got wise to that, and so an arms race is developing. The current technique which seems to work pretty much all the time is to throw firecrackers into the water.

They’re starting to move on to other types of boats too. Small fishing boats are increasingly being attacked.

This is not going to end well. Either they will finally kill someone, which will likely result in a cull, or they’re going to fuck with the wrong boat. In a few months the tuna migrate north towards Normandy. The orcas follow them. If they start attacking French fishing boats, I can’t imagine those guys taking any shit. Sail boats are pleasure craft and our response has been to try and avoid them, but that’s not going to be the case with fishing boats, and the French are not known for calm and gentle responses to things that threaten their livelihoods.

Watch this space, I guess. The hope is that this behaviour is a fad that will go out of fashion. If it doesn’t, it’s going to end up in deaths; possibly humans, definitely orcas.