Seventeen new species of earthworms are now a matter of scientific record, thanks to four papers published in Zootaxa this fall that were coauthored by Professor Sam James
These species were discovered in remote areas in the eastern Amazon region and the state of Rio Grande do Sul in Brazil.
Dr. James has now described around 200 new species of earthworms. In addition to many trips to Brazil, he has done fieldwork in 20 other countries: Argentina, Martinique, Thailand, India, Laos, Korea, Madagascar, Kenya, Gabon, South Africa, Ghana, Samoa, Fiji, Philippines, France, Spain, Portugal, Hungary, Romania, and the U.S.
“I was a longtime gardener and always thought of earthworms as a beneficial set of organisms,” Dr. James said. “Early in my career when I saw that there was very little research on earthworms in the U.S. and much of the world, I decided to make this a focus.”
He said that the study of earthworms helps to understand the ecology of a region and the ecological impacts of developments such as the introduction of agriculture.
“The details of an earthworm’s structure tell its ecological function,” he said. “And looking at the totality of the population of earthworms in a region helps assess the human impact. The original species don’t survive the transition to agriculture and may never come back.”
In addition to species identification, Dr. James has also researched earthworm DNA to better understand the evolution and diversification of the earthworm ancestral tree. He said this research can also be applied to ecological questions about the functional diversity of earthworms.
It also helps scientists understand the worldwide spread of organisms on Earth over the millennia.
“We look at what processes were going on then, including the movement of the continents, and what are going on now,” he said. Dr. James’s research was continually funded by the National Science Foundation from 2000–2016. In addition to studying earthworm ecology, evolution, and diversity, he said that taxonomy – describing and naming a species and putting it in context – simply helps biologists clearly communicate about what they’re doing.
Dr. James is chair of MUM’s Department of Sustainable Living. He teaches soil science, ecology, soil ecology, and fundamentals of living systems. He has a collection of additional new species that he hasn’t yet described and is continuing to work on publication of descriptions of them. He also continues to investigate earthworm evolution with genomic scale data sets, and is working with teams of researchers to study invasive earthworm ecology in the U.S.