Seventy thousand species.
That’s the best guess for the tally of life, including plants, animals and fungi, found in Britain and Ireland.
And it’s the target of one of biology’s most ambitious projects – scientists want to map the DNA of every single one of these organisms.
Having these genomes – each a complete set of genetic information for a species – could transform how we understand the natural world. And there could be benefits for us too in the hunt for nature-inspired medicines and materials.
In Plymouth, the starting point for this immense task is some thick, sticky mud.
Sediment scooped up from the bottom of the Plymouth Sound has been hoisted onto the deck of the research vessel that belongs to the Marine Biological Association.
It’s placed in a sieve and hosed off, revealing a host of wriggling creatures.
“You can see we’ve got some bivalves, which are related to clams and mussels. We’ve also got a gastropod shell – these are quite similar to terrestrial garden snails. And we’ve got some brittle stars. So lots of different taxa (groups of organisms), lots of different types of animals, which is great,” explains marine biologist Patrick Adkins.
Today he’s focussing on marine worms known as polychaetes, and there are lots living in the sediment.
Some look like earthworms and others are covered in tiny bristles, squiggling about. But the weirdest is the mud owl. If you squint, its markings look a bit like the face of an owl, until it extends a tubular proboscis, shattering the illusion.
All of them will have their genomes sequenced for the project, which is called the Darwin Tree of Life.
“Even if you look at polychaetes, which is just one group of worms, it’s a big task with hundreds and hundreds of species,” Patrick says.
“We’ve now got over 100 species of polychaetes collected – it seems like a lot, but really, it’s just the beginning.”