Ice ages & Earthworms

16,000 years ago. Whooh, that's a lot of ice. Looks cold.

In fact, it was so freakin' cold that the ground froze solid in many places, killing off the little things that lived in it. In Eurasia, the only places that did not experience that die-off were the deep river valleys: the Tigris, Euphrates, and Indus. Therefore, they still had worms. Lumbricus terrestris. Essential to agriculture. Worms are essentially self-propelled compost-makers. Little moving containers for great changes.  They break down plant and animal castoff faster than anything else, essential for the quick turnover one needs for annual plantings -- and it has to be broken down each year, because the cold, cold winter means everything hibernates and the soil must be ready for the next season's crop's demands. You can accurately gauge a garden's health by the number of worms in a shovel of soil.

So what about the rest of the world? Areas without worms?

The Americas did not have native soil-dwelling composters.  There were (and are) a lot of interesting types of worms, but nothing that were as insanely efficient at turning last year's garden into next year's garden.  That's part of the reason why the first European settlements did so poorly. The little earthworm cocoons (carried on boots, seeds, roots, etc) take time to establish. So things were a little hungry the first couple of years because the European’s standard annual-planting agriculture just didn’t have the foundation it needed.




Fun fact for this post: there are hundreds of different kinds of earthworms… perhaps thousands… and this has a really fun skit about their reproduction: Green Porno -- last tab on the right, GP #1  (It's a little tiny bit adult, but generally talks about the reproduction of bugs and other fascinating things.)