title: Fungi identify the geographic origin of dust samples.
abstract: There is a long history of archaeologists and forensic scientists using pollen found in a dust sample to identify its geographic origin or history. Such palynological approaches have important limitations as they require time-consuming identification of pollen grains, a priori knowledge of plant species distributions, and a sufficient diversity of pollen types to permit spatial or temporal identification. We demonstrate an alternative approach based on DNA sequencing analyses of the fungal diversity found in dust samples. Using nearly 1,000 dust samples collected from across the continental U.S., our analyses identify up to 40,000 fungal taxa from these samples, many of which exhibit a high degree of geographic endemism. We develop a statistical learning algorithm via discriminant analysis that exploits this geographic endemicity in the fungal diversity to correctly identify samples to within a few hundred kilometers of their geographic origin with high probability. In addition, our statistical approach provides a measure of certainty for each prediction, in contrast with current palynology methods that are almost always based on expert opinion and devoid of statistical inference. Fungal taxa found in dust samples can therefore be used to identify the origin of that dust and, more importantly, we can quantify our degree of certainty that a sample originated in a particular place. This work opens up a new approach to forensic biology that could be used by scientists to identify the origin of dust or soil samples found on objects, clothing, or archaeological artifacts.
authors: Department of Statistics, North Carolina State University, Raleigh, North Carolina, United States of America.
authors: Neal S
authors: NS
authors: Grantham
authors: Department of Statistics, North Carolina State University, Raleigh, North Carolina, United States of America.
authors: Brian J
authors: BJ
authors: Reich
authors: Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors: Krishna
authors: K
authors: Pacifici
authors: Department of Statistics, North Carolina State University, Raleigh, North Carolina, United States of America.
authors: Eric B
authors: EB
authors: Laber
authors: Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America.
authors: Holly L
authors: HL
authors: Menninger
authors: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, United States of America.
authors: Jessica B
authors: JB
authors: Henley
authors: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, United States of America.
authors: Albert
authors: A
authors: Barberán
authors: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, United States of America; Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, United States of America.
authors: Jonathan W
authors: JW
authors: Leff
authors: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, United States of America; Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, United States of America.
authors: Noah
authors: N
authors: Fierer
authors: Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America.
authors: Robert R
authors: RR
authors: Dunn
mesh_terms: D001106:Archaeology; D004391:Dust; D005658:Fungi / Q000145:classification / Q000235:genetics*; D014644:Genetic Variation; D011058:Pollen / Q000235:genetics* / Q000382:microbiology
chemical_list: D004391:Dust