Karl J. Reinhard

Are Ascaris lumbricoides and Ascaris suum a single species

Since the original description and naming of Ascaris lumbricoides from humans by Linnaeus in 1758 and later of Ascaris suum from pigs by Goeze 1782, these species have been considered to be valid. Four hypotheses relative to the conspecificity or lack thereof (and thus origin of these species) are possible: 1) Ascaris lumbricoides (usually infecting humans) and Ascaris suum (recorded mostly from pigs) are both valid species, with the two species originating via a speciation event from a common ancestor sometime before the domestication of pigs by humans, or 2) Ascaris lumbricoides in humans is derived directly from the species A. suum found in pigs with A. suum then existing as a persistent ancestor after formation of A. lumbricoides, or 3) Ascaris suum is derived directly from A. lumbricoides with the persistent ancestor being A. lumbricoides and A. suum being the newly derived species, and finally, 4) Ascaris lumbricoides and A. suum are the same species, this hypothesis being supported by studies showing both low morphological and low genetic divergence at several genes. We present and discuss paleoparasitological and genetic evidence that complement new data to evaluate the origin and evolution of Ascaris spp. in humans and pigs, and the uniqueness of the species in both hosts. Finally, we conclude that Ascaris lumbricoides and A. suum are a single species and that the name A. lumbricoides Linnaeus 1758 has taxonomic priority; therefore A. suum Goeze 1782 should be considered a synonym of A. lumbricoides.

Parasitology As an Interpretive Tool in Archaeology

Parasitological studies of archaeological sites can be used to interpret past behavior and living conditions. During the 1980s problem-oriented research into prehistoricand historical-period parasitism developed and resulted in the field of archaeoparasitology. Archaeoparasitology attempts to integrate parasite data into archaeological theory and interpretation. Within the last decade, four major archaeoparasitological laboratories emerged. They developed interpretive frameworks that apply parasitological data to a remarkable variety of prehistoric behaviors. Parasite remains can be used to reconstruct aspects of diet, health, and other behaviors such as transhumance and trade. Finally, analysis of the distribution ofparasite remains can be used to interpret aspects of site-formation processes.

Parasite remains in archaeological sites

Organic remains can be found in many different environments. They are the most significant source for paleoparasitological studies as well as for other paleoecological reconstruction. Preserved paleoparasitological remains are found from the driest to the moistest conditions. They help us to understand past and present diseases and therefore contribute to understanding the evolution of present human sociality, biology, and behavior. In this paper, the scope of the surviving evidence will be briefy surveyed, and the great variety of ways it has been preserved in different environments will be discussed. This is done to develop to the most appropriated techniques to recover remaining parasites. Different techniques applied to the study of paleoparasitological remains, preserved in different environments, are presented. The most common materials used to analyze prehistoric human groups are reviewed, and their potential for reconstructing ancient environment and disease are emphasized. This paper also urges increased cooperation among archaeologists, paleontologists, and paleoparasitologists.

Insights from Characterizing Extinct Human Gut Microbiomes

In an effort to better understand the ancestral state of the human distal gut microbiome, we examine feces retrieved from archaeological contexts (coprolites). To accomplish this, we pyrosequenced the 16S rDNA V3 region from duplicate coprolite samples recovered from three archaeological sites, each representing a different depositional environment: Hinds Cave (∼8000 years B.P.) in the southern United States, Caserones (1600 years B.P.) in northern Chile, and Rio Zape in northern Mexico (1400 years B.P.). Clustering algorithms grouped samples from the same site. Phyletic representation was more similar within sites than between them. A Bayesian approach to source-tracking was used to compare the coprolite data to published data from known sources that include, soil, compost, human gut from rural African children, human gut, oral and skin from US cosmopolitan adults and non-human primate gut. The data from the Hinds Cave samples largely represented unknown sources. The Caserones samples, retrieved directly from natural mummies, matched compost in high proportion. A substantial and robust proportion of Rio Zape data was predicted to match the gut microbiome found in traditional rural communities, with more minor matches to other sources. One of the Rio Zape samples had taxonomic representation consistent with a child. To provide an idealized scenario for sample preservation, we also applied source tracking to previously published data for Ötzi the Iceman and a soldier frozen for 93 years on a glacier. Overall these studies reveal that human microbiome data has been preserved in some coprolites, and these preserved human microbiomes match more closely to those from the rural communities than to those from cosmopolitan communities. These results suggest that the modern cosmopolitan lifestyle resulted in a dramatic change to the human gut microbiome.

Ten thousand years of head lice infection.

9xMummies and mummification practices in the southwestern and southeastern United States. El-Najjar et al. : 121–137See all References, 10xSee all References, 11x) Diet and environment determined from analysis of prehistoric coprolites from an archaeological site near Zape Chico, Durango, Mexico. Reinhard, K.J. and Largent, F.B. J. Paleopathol. Monograph. 1989; 1: 151–156See all References, 12xArchaeoparasitology in North America. Reinhard, K.J. Am. J. Phys. Anthropol. 1990; 82: 145–162Crossref | PubMed | Scopus (67)See all References, 13xPaleoparasitology of oxyuriasis. Araujo, A. et al. Anais da Academia Nacionalde Medicina. 1997; 157: 20–24See all References, 14xHuman enterobiasis and evolution (origin, specificity and transmission) . Hugot, J.P. Parasite. 1999; 6: 106–112See all References

HELMINTH REMAINS FROM PREHISTORIC INDIAN COPROLITES ON THE COLORADO PLATEAU

Examination of coprolites excavated from archaeological sites in the Americas demonstrates excellent preservation of helminth eggs and, in some cases, larvae. To gain an understanding of helminth parasitism in prehistory on the Colorado Plateau of Arizona, New Mexico, and Utah, 319 coprolites from 5 archaeological sites were analyzed. Helminth eggs and larvae were recovered after the coprolites were rehydrated, screened, and sedimented. At a sixth site, soils excavated from 5 rooms used as latrine areas were processed with palynological techniques. The results indicate that all but 1 of the prehistoric populations examined were infected with intestinal worms. The helminths implicated are Enterobius vermicularis, Trichuris trichiura, cf. Ascaris lumbricoides, cf. Trichostrongylus sp., cf. Strongyloides sp., taeniid cestodes, and hymenolepidid cestodes. The study suggests that prehistoric hunter-gatherer peoples carried fewer helminth parasites than agriculturalists. At 1 site, it appears that increased helminth parasitism preceded abandonment of the village.

Paleoparasitology of Chagas disease: a review

One hundred years since the discovery of Chagas disease associated with Trypanosoma cruzi infection, growing attention has focused on understanding the evolution in parasite-human host interaction. This interest has featured studies and results from paleoparasitology, not only the description of lesions in mummified bodies, but also the recovery of genetic material from the parasite and the possibility of analyzing such material over time. The present study reviews the evidence of Chagas disease in organic remains excavated from archeological sites and discusses two findings in greater detail, both with lesions suggestive of chagasic megacolon and confirmed by molecular biology techniques. One of these sites is located in the United States, on the border between Texas and Mexico and the other in state of Minas Gerais, in the Brazilian cerrado (savannah). Dated prior to contact with Europeans, these results confirm that Chagas disease affected prehistoric human groups in other regions outside the Andean altiplanos and other transmission areas on the Pacific Coast, previously considered the origin of T. cruzi infection in the human host.

Parasites as Probes for Prehistoric Human Migrations

Host-specific parasites of humans are used to track ancient migrations. Based on archaeoparasitology, it is clear that humans entered the New World at least twice in ancient times. The archaeoparasitology of some intestinal parasites in the New World points to migration routes other than the Bering Land Bridge. Helminths have been found in mummies and coprolites in North and South America. Hookworms (Necator and Ancylostoma), whipworms (Trichuris trichiura) and other helminths require specific conditions for life-cycle completion. They could not survive in the cold climate of the northern region of the Americas. Therefore, humans would have lost some intestinal parasites while crossing Beringia. Evidence is provided here from published data of pre-Columbian sites for the peopling of the Americas through trans-oceanic or costal migrations.

Parasitism, the diversity of life, and paleoparasitology

The parasite-host-environment system is dynamic, with several points of equilibrium. This makes it difficult to trace the thresholds between benefit and damage, and therefore, the definitions of commensalism, mutualism, and symbiosis become worthless. Therefore, the same concept of parasitism may encompass commensalism, mutualism, and symbiosis. Parasitism is essential for life. Life emerged as a consequence of parasitism at the molecular level, and intracellular parasitism created evolutive events that allowed species to diversify. An ecological and evolutive approach to the study of parasitism is presented here. Studies of the origin and evolution of parasitism have new perspectives with the development of molecular paleoparasitology, by which ancient parasite and host genomes can be recovered from disappeared populations. Molecular paleoparasitology points to host-parasite co-evolutive mechanisms of evolution traceable through genome retrospective studies.

Human Dental Microwear Caused by Calcium Oxalate Phytoliths in Prehistoric Diet of the Lower Pecos Region, Texas

Recent research demonstrates that silica phytoliths of dietary origin are associated with microwear of human teeth. Previous research has shown that severe enamel microwear and dental wear characterizes Archaic hunter-gatherers in the lower Pecos region of west Texas. Calcium oxalate crystals are especially common in Archaic coprolites. The vast majority are derived from prickly pear and agave, which were the dietary staples in west Texas for 6,000 years. The calcium oxalate phytoliths are harder than enamel. Therefore, calcium oxalate crystals are the most likely source of previously documented dental microwear and wear in the lower Pecos region.