Oakley Shields
Oakley Shields | |
|---|---|
| Residence | Mariposa, CA, United States |
| Nationality | American |
| Known for | Expanding Earth |
| Scientific career | |
| Fields | Lepidopterology, Biogeography |
Oakley Shields is an American lepidopterist and biogeographer based in Mariposa, California. He is known for his taxonomic and distributional work on North American blue butterflies of the family Lycaenidae, and for his support of the Expanding Earth hypothesis, which he came to favor on biogeographic grounds.
Biography
Shields worked as an entomologist and biogeographer with a particular interest in the butterflies of western North America. His research combined field studies of butterfly biology and distribution with broader questions of historical biogeography and the arrangement of the continents. He resides in Mariposa County, California, on the western edge of the Sierra Nevada near Yosemite.
His interest in Earth expansion grew out of his biogeographic studies. In 1975 he assisted the geologist S. Warren Carey by proofing, editing, and carrying out some research for Carey's book The Expanding Earth. Shields has written that reflecting on the many trans-Pacific biotic links, and on paleontologic links between Malaysia and Australia that he regarded as difficult to reconcile with a wide Tethys seaway, led him to embrace Earth expansion.
Scientific contributions
Lepidopterology
Shields published a series of studies on North American Philotes and related blues (Lepidoptera: Lycaenidae). His work in the Bulletin of the Allyn Museum during the early 1970s examined the biology, distribution, and taxonomy of these butterflies, including their roosting behavior and their associations with tending ants, parasites, and predators, and treated the biology and distribution of Philotes sonorensis. In 1975 he described new subspecies within the group, among them the taxon later placed as Euphilotes glaucon comstocki, based on material from the Tehachapi area of California.
In 1989 Shields published "World Numbers of Butterflies" in the Journal of the Lepidopterists' Society (volume 43, number 3, pages 178–183), estimating the world total of butterfly species at about 17,280, grouped into roughly 1,855 genera, 35 subfamilies, and 7 families. He also wrote on the relationship between butterfly distribution and continental drift.
Expanding Earth
Shields is a supporter of the Expanding Earth hypothesis, arguing for it primarily from biogeography rather than geophysics. He has held that present and past trans-Pacific biotic connections, together with faunal links between now widely separated lands, are more readily explained by an Earth of formerly smaller radius than by plate tectonics. He has connected these ideas to a decreasing gravitational constant in an expanding universe, following the earlier suggestions of Egyed, and has pointed to surface features of the Moon and Mercury as possible signs of planetary expansion. These positions place Shields outside the mainstream geological consensus, which regards plate tectonics as well supported by geophysical and paleomagnetic evidence.
Abstracts
- 1997 - "Is Plate Tectonics Standing the Test of Time" (Read in full)
- 1997 - "Rapid Earth Expansion : An Eclectic View" (Read in full)