Privileged Planet: worms' contribution to soils (Introduction)

by David Turell , Monday, March 11, 2024, 22:36 (46 days ago) @ David Turell

Not much to grow on without worms turning soil over as they work:

https://www.nature.com/articles/d41586-024-00690-9

"Nature spoke to palaeontologist Luke Parry at the University of Oxford, UK. He studies worms from the Cambrian and Ordovician periods, which together lasted from roughly 540 million to 444 million years ago.

"There are annelid worms that get up to several metres in length called eunicid worms, a type of bristle worm. They’re pretty gnarly — they have big jaws, they look a bit like Graboids from the 1990 film Tremors. Some of them are ambush predators. They eat octopuses, squid, vertebrates.

"There are some earthworms that get really big, as well. Megascolides reaches up to 2 metres. The biggest ones are from Australia.

"The worms in Dune have lots of teeth around their mouths, and that’s what the Fremen use to make their crysknives. There are worms like that, called priapulids. These are the sorts that were making the first complex burrows in the early Cambrian. They use all of these teeth, called scalids, on a proboscis to drag themselves through burrows. Alitta worms — sandworms — and ragworms have teeth for catching prey. Some leeches have teeth.

***

"Before the advent of worms, the sea floor would have been smothered with what are called microbial mats. All the sediment would have been anoxic, without oxygen. If you’ve ever gone swimming in a river or a lake and it’s muddy and you plunge your foot into it, and it’s smelly and anoxic, that’s basically what the entire sea-floor environment would have been around the world.

"Then, all of a sudden, some animals evolve a wormy body plan that allows them to move in three dimensions. They start burrowing into sediments, and that means that oxygen can get into the sediments and complex animal life can live there. It opens up new ways of making a living. Worms are part of this fundamental restructuring of the world. (my bold)

***

"There are about 30 animal body plans — what we call the animal phyla, the big groups that we chop up animal diversity into — and more than half of them are worms. It’s a really good, versatile way of making a living. Lots of things that didn’t start off as worms just become worms. There are groups of lizards that lose their limbs, like snakes and amphisbaenians, worm lizards. There are worms that live in hydrothermal vents in the deep sea."

Comment: the advent of worms following lichen breaking down rocks made the very fertile soils we have on Earth. samev old story. Life on earth modified the planet into what is present today. Taken from an interview comparing 'Dune' film worms to real ones.