Month: September 2022

DARWIN WROTE, “No other creature on earth has done so much for mankind” as earthworms. https://lnkd.in/eZmt3Ts View in LinkedIn

HISTORICAL ROLE. “It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.” (Charles Darwin 1881). " " https://lnkd.in/e3HEbhg View in LinkedIn

40 YEAR PROJECT. "Darwin’s association and interest with earthworms came shortly after his famous voyage on the HMS Beagle. His uncle showed him a spot in his garden where he had spread ashes and lime several years before. Darwin was amazed to see how soil cast up by earthworms had buried the substances. He went home and began a series of earthworm experiments that would go for the next 40 years." https://lnkd.in/ebEFwre View in LinkedIn

SPECIES VAGUENESS. "In his most famous book On the Origin of Species, Charles Darwin (1859) did not define what species are and how they can be distinguished from varieties. Darwin's relaxed opinion concerning species definitions may have been the reason why he did not identify the species of earthworms he was investigating." https://lnkd.in/e8jbAfG View in LinkedIn

WORMS AND BILLIARDS. "Darwin conducted both lab experiments in his study and billiard room and field investigations in his extensive gardens. He published his findings in 1881 in a book titled The Formation of Vegetable Mould through the Action of Worms, with Observations of their Habits. The book sold 6000 copies in its first year, selling faster than On the Origin of Species had when it was first published." https://lnkd.in/ebEFwre View in LinkedIn

DARWIN "conducted a 29-year experiment on chalk at a field near his house. Objects of all sorts "work themselves downards" as farmers say. Large stones sink because worms fill up any hollows with castings, then eject them beyond the perimeter and the ground around them starts to rise. He visited Stonehenge and found some outer stones partly buried, the turf sloping up to meet them." https://lnkd.in/exyGWjD View in LinkedIn

VAST EARTHWORKS. "Darwin described the volume of soil that earthworms swallow and eject as castings, or earthworm manure, and he reported that an acre of garden soil could contain more than 50,000 earthworms and yield 18 tons of castings per year. He studied earthworms’ ability to bury objects of every sort—from handfuls of chalk scattered on the ground to Roman ruins that had, he believed, been preserved for archaeologists by an industrious earthworm population." https://lnkd.in/eSjBc5w View in LinkedIn

"DARWIN'S estimate that more than 50,000 worms could inhabit an acre of soil was in fact quite low; scientists have shown the figure to be one million. Earthworms in the Nile River valley can deposit up to 1,000 tons of castings per acre, which helps to explain the astonishing fertility of Egypt’s agricultural land. As Darwin had only begun to suspect, earthworms pass the top few inches of soil through their guts every year." http://archive.wilsonquarterly.com/essays/darwins-worms View in LinkedIn

WORMS PER ACRE. "Darwin estimated that arable land contains up to 53,000 worms per acre (13/m2), but more recent research from Rothamsted Experimental Station has produced figures suggesting that even poor soil may support 250,000/acre (62/m2), whilst rich fertile farmland may have up to 1,750,000/acre (432/m2), meaning that the weight of earthworms beneath a farmer's soil could be greater than that of the livestock upon its surface." https://lnkd.in/erzksPW View in LinkedIn

FORMING HEALTHY SOILS. "Darwin first recognised this importance of earthworms in soil formation (pedogenesis) by them acting as agents of physical and chemical decomposition (weathering of rocks), by promoting humus formation, and by improving soil texture. More recent work has shown that they also influence soil pH and enrich the soil." https://lnkd.in/e8jbAfG View in LinkedIn