My Jacaranda tree is in full bloom!
Today’s biology lesson answers the question Why Do We Keep Getting Diseases from Bats? with a look at the differences between our respective immune systems.
…bat cells just continually assume they’re under attack and never stop fighting viruses, regardless of whether they’ve detected any. This is surprising. Interferon is a really powerful molecule, and continually producing it should have the same effect on a cell as continually putting a factory on red alert. It should make the cell run much worse, and cause a lot of collateral damage.
After all, when this sort of immune system overreaction happens in humans, humans get serious disorders, like Multiple Sclerosis and Lupus. Bats do not tend to get these. In fact, many bat species live around 20 years on average, which is not only way longer than it should have with its overactive immune system, but is exceptionally long for such a small animal. To give a comparison, rats live a year or two, as do rabbits.
There’s lots more, explaining how bats can live such relatively long lives with an “always-on” immune system, and also why their immune system evolved to be that way.
As an aside, I wasn’t aware that we had Natural Killer (NK) cells…
NK cells are as heavy duty as their name implies; while their cousins, T cells, kill any cell that displays signs of being infected, NK cells kill any cells that don’t display signs of being not infected. Viruses will frequently prevent cells from indicating that they’re infected, so NK cells just kill any cell that looks like it’s hiding something.
No messing around there!
An article that’s been sitting in my unread tabs for a while now, but is pretty cool. We’ve known for ages that spiders can fly, but we’ve only just figured out how they do it.
Ballooning spiders operate within this planetary electric field. When their silk leaves their bodies, it typically picks up a negative charge. This repels the similar negative charges on the surfaces on which the spiders sit, creating enough force to lift them into the air. And spiders can increase those forces by climbing onto twigs, leaves, or blades of grass. Plants, being earthed, have the same negative charge as the ground that they grow upon, but they protrude into the positively charged air. This creates substantial electric fields between the air around them and the tips of their leaves and branches—and the spiders ballooning from those tips.
File under ‘Nature Is Cool.’
Fascinating article on hyenas, though I’m not sure being outed as the Donald Trump of the savannah is an upgrade :-)
Even lone hyenas have been known to catch impressively large prey — one bold strategy being to lock on to the animal’s testicles and hang on until the victim bleeds out.
Grab ‘em by the bollix!