Marie Hammer

Marie Signe Hammer née Jørgensen (1907–2002) was a Danish zoologist and entomologist who specialized in moss mites. In the 1930s and 1940s, she undertook research in Iceland, the Faroe Islands and Greenland. She later extended her investigations to North and South America, New Zealand, and Asia, discovering some 150 new genera and almost a thousand new species. Her research supported the dispersal of species as a result of continental drift as described in her 1979 thesis together with John Anthony Wallwork titled A Review of the World Distribution of oribatid mites in Relation to Continental Drift.

Early life Born in Copenhagen on 20 March 1907, Jørgensen was the daughter of Niels Rasmussen Jørgensen and Alma Kristine Rasmussen. After her parents had divorced when she was seven, she was brought up by her mother on a farm in Nivå. After matriculating from Rungsted State School in 1926, she studied zoology at the University of Copenhagen, earning a master's degree in 1932. In 1933, with a view to extending her research to Greenland, she joined Knud Rasmussen on his final Thule expedition. She studied microfauna, in particular springtails (Collembola) and moss mites (Oribatida), documenting her discoveries in later publications. Commenting on how little she had earned from her life's work, she explained: "50 years for Minerva. Despite this paltry financial result, I would not swap my life with anyone — I have obtained what I wanted and lived my life in my own way."

Marie Hammer and her husband spent their later life in an old farmhouse near Fredensborg.

A biographical novel based on the life and endeavours of Marie Hammer was published in 2021 by Danish author Eva Tind entitled "Kvinden der samlede verden" ("The woman who assembled the world") referring to continental drift after the former supercontinent, Pangaea, and her scientific support of this theory.