Publications by authors named "Richard Potts"

30 Publications

  • Page 1 of 1

Microevolution in our megadont relative.

Authors:
Richard Potts

Nat Ecol Evol 2021 01;5(1):14-16

Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.

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http://dx.doi.org/10.1038/s41559-020-01339-2DOI Listing
January 2021

Increased ecological resource variability during a critical transition in hominin evolution.

Sci Adv 2020 Oct 21;6(43). Epub 2020 Oct 21.

Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA.

Although climate change is considered to have been a large-scale driver of African human evolution, landscape-scale shifts in ecological resources that may have shaped novel hominin adaptations are rarely investigated. We use well-dated, high-resolution, drill-core datasets to understand ecological dynamics associated with a major adaptive transition in the archeological record ~24 km from the coring site. Outcrops preserve evidence of the replacement of Acheulean by Middle Stone Age (MSA) technological, cognitive, and social innovations between 500 and 300 thousand years (ka) ago, contemporaneous with large-scale taxonomic and adaptive turnover in mammal herbivores. Beginning ~400 ka ago, tectonic, hydrological, and ecological changes combined to disrupt a relatively stable resource base, prompting fluctuations of increasing magnitude in freshwater availability, grassland communities, and woody plant cover. Interaction of these factors offers a resource-oriented hypothesis for the evolutionary success of MSA adaptations, which likely contributed to the ecological flexibility typical of foragers.
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http://dx.doi.org/10.1126/sciadv.abc8975DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7577727PMC
October 2020

Investigating Biotic Interactions in Deep Time.

Trends Ecol Evol 2021 01 13;36(1):61-75. Epub 2020 Oct 13.

School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.

Recent renewed interest in using fossil data to understand how biotic interactions have shaped the evolution of life is challenging the widely held assumption that long-term climate changes are the primary drivers of biodiversity change. New approaches go beyond traditional richness and co-occurrence studies to explicitly model biotic interactions using data on fossil and modern biodiversity. Important developments in three primary areas of research include analysis of (i) macroevolutionary rates, (ii) the impacts of and recovery from extinction events, and (iii) how humans (Homo sapiens) affected interactions among non-human species. We present multiple lines of evidence for an important and measurable role of biotic interactions in shaping the evolution of communities and lineages on long timescales.
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http://dx.doi.org/10.1016/j.tree.2020.09.001DOI Listing
January 2021

The formation of human populations in South and Central Asia.

Authors:
Vagheesh M Narasimhan Nick Patterson Priya Moorjani Nadin Rohland Rebecca Bernardos Swapan Mallick Iosif Lazaridis Nathan Nakatsuka Iñigo Olalde Mark Lipson Alexander M Kim Luca M Olivieri Alfredo Coppa Massimo Vidale James Mallory Vyacheslav Moiseyev Egor Kitov Janet Monge Nicole Adamski Neel Alex Nasreen Broomandkhoshbacht Francesca Candilio Kimberly Callan Olivia Cheronet Brendan J Culleton Matthew Ferry Daniel Fernandes Suzanne Freilich Beatriz Gamarra Daniel Gaudio Mateja Hajdinjak Éadaoin Harney Thomas K Harper Denise Keating Ann Marie Lawson Matthew Mah Kirsten Mandl Megan Michel Mario Novak Jonas Oppenheimer Niraj Rai Kendra Sirak Viviane Slon Kristin Stewardson Fatma Zalzala Zhao Zhang Gaziz Akhatov Anatoly N Bagashev Alessandra Bagnera Bauryzhan Baitanayev Julio Bendezu-Sarmiento Arman A Bissembaev Gian Luca Bonora Temirlan T Chargynov Tatiana Chikisheva Petr K Dashkovskiy Anatoly Derevianko Miroslav Dobeš Katerina Douka Nadezhda Dubova Meiram N Duisengali Dmitry Enshin Andrey Epimakhov Alexey V Fribus Dorian Fuller Alexander Goryachev Andrey Gromov Sergey P Grushin Bryan Hanks Margaret Judd Erlan Kazizov Aleksander Khokhlov Aleksander P Krygin Elena Kupriyanova Pavel Kuznetsov Donata Luiselli Farhod Maksudov Aslan M Mamedov Talgat B Mamirov Christopher Meiklejohn Deborah C Merrett Roberto Micheli Oleg Mochalov Samariddin Mustafokulov Ayushi Nayak Davide Pettener Richard Potts Dmitry Razhev Marina Rykun Stefania Sarno Tatyana M Savenkova Kulyan Sikhymbaeva Sergey M Slepchenko Oroz A Soltobaev Nadezhda Stepanova Svetlana Svyatko Kubatbek Tabaldiev Maria Teschler-Nicola Alexey A Tishkin Vitaly V Tkachev Sergey Vasilyev Petr Velemínský Dmitriy Voyakin Antonina Yermolayeva Muhammad Zahir Valery S Zubkov Alisa Zubova Vasant S Shinde Carles Lalueza-Fox Matthias Meyer David Anthony Nicole Boivin Kumarasamy Thangaraj Douglas J Kennett Michael Frachetti Ron Pinhasi David Reich

Science 2019 09;365(6457)

Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.

By sequencing 523 ancient humans, we show that the primary source of ancestry in modern South Asians is a prehistoric genetic gradient between people related to early hunter-gatherers of Iran and Southeast Asia. After the Indus Valley Civilization's decline, its people mixed with individuals in the southeast to form one of the two main ancestral populations of South Asia, whose direct descendants live in southern India. Simultaneously, they mixed with descendants of Steppe pastoralists who, starting around 4000 years ago, spread via Central Asia to form the other main ancestral population. The Steppe ancestry in South Asia has the same profile as that in Bronze Age Eastern Europe, tracking a movement of people that affected both regions and that likely spread the distinctive features shared between Indo-Iranian and Balto-Slavic languages.
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http://dx.doi.org/10.1126/science.aat7487DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6822619PMC
September 2019

Chronology of the Acheulean to Middle Stone Age transition in eastern Africa.

Science 2018 04 15;360(6384):95-98. Epub 2018 Mar 15.

Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA.

The origin of the Middle Stone Age (MSA) marks the transition from a highly persistent mode of stone toolmaking, the Acheulean, to a period of increasing technological innovation and cultural indicators associated with the evolution of We used argon-40/argon-39 and uranium-series dating to calibrate the chronology of Acheulean and early MSA artifact-rich sedimentary deposits in the Olorgesailie basin, southern Kenya rift. We determined the age of late Acheulean tool assemblages from 615,000 to 499,000 years ago, after which a large technological and faunal transition occurred, with a definitive MSA lacking Acheulean elements beginning most likely by ~320,000 years ago, but at least by 305,000 years ago. These results establish the oldest repository of MSA artifacts in eastern Africa.
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http://dx.doi.org/10.1126/science.aao2216DOI Listing
April 2018

Long-distance stone transport and pigment use in the earliest Middle Stone Age.

Science 2018 04 15;360(6384):90-94. Epub 2018 Mar 15.

Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA.

Previous research suggests that the complex symbolic, technological, and socioeconomic behaviors that typify had roots in the middle Pleistocene <200,000 years ago, but data bearing on human behavioral origins are limited. We present a series of excavated Middle Stone Age sites from the Olorgesailie basin, southern Kenya, dating from ≥295,000 to ~320,000 years ago by argon-40/argon-39 and uranium-series methods. Hominins at these sites made prepared cores and points, exploited iron-rich rocks to obtain red pigment, and procured stone tool materials from ≥25- to 50-kilometer distances. Associated fauna suggests a broad resource strategy that included large and small prey. These practices imply notable changes in how individuals and groups related to the landscape and to one another and provide documentation relevant to human social and cognitive evolution.
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http://dx.doi.org/10.1126/science.aao2646DOI Listing
April 2018

Environmental dynamics during the onset of the Middle Stone Age in eastern Africa.

Science 2018 04 15;360(6384):86-90. Epub 2018 Mar 15.

Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada.

Development of the African Middle Stone Age (MSA) before 300,000 years ago raises the question of how environmental change influenced the evolution of behaviors characteristic of early We used temporally well-constrained sedimentological and paleoenvironmental data to investigate environmental dynamics before and after the appearance of the early MSA in the Olorgesailie basin, Kenya. In contrast to the Acheulean archeological record in the same basin, MSA sites are associated with a markedly different faunal community, more pronounced erosion-deposition cycles, tectonic activity, and enhanced wet-dry variability. Aspects of Acheulean technology in this region imply that, as early as 615,000 years ago, greater stone material selectivity and wider resource procurement coincided with an increased pace of land-lake fluctuation, potentially anticipating the adaptability of MSA hominins.
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http://dx.doi.org/10.1126/science.aao2200DOI Listing
April 2018

New developments in sediment coring and implications for understanding human evolution.

Authors:
Richard Potts

Theor Biol Forum 2018 Jan 1;111(1-2):99-104. Epub 2018 Jan 1.

Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.

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http://dx.doi.org/10.19272/201811402011DOI Listing
January 2018

Direct radiocarbon dating and DNA analysis of the Darra-i-Kur (Afghanistan) human temporal bone.

J Hum Evol 2017 06 4;107:86-93. Epub 2017 May 4.

Oxford Radiocarbon Accelerator Unit, Research Laboratory for Archaeology and the History of Art, University of Oxford, Oxford, OX1 3QY, United Kingdom.

The temporal bone discovered in the 1960s from the Darra-i-Kur cave in Afghanistan is often cited as one of the very few Pleistocene human fossils from Central Asia. Here we report the first direct radiocarbon date for the specimen and the genetic analyses of DNA extracted and sequenced from two areas of the bone. The new radiocarbon determination places the find to ∼4500 cal BP (∼2500 BCE) contradicting an assumed Palaeolithic age of ∼30,000 years, as originally suggested. The DNA retrieved from the specimen originates from a male individual who carried mitochondrial DNA of the modern human type. The petrous part yielded more endogenous ancient DNA molecules than the squamous part of the same bone. Molecular dating of the Darra-i-Kur mitochondrial DNA sequence corroborates the radiocarbon date and suggests that the specimen is younger than previously thought. Taken together, the results consolidate the fact that the human bone is not associated with the Pleistocene-age deposits of Darra-i-Kur; instead it is intrusive, possibly re-deposited from upper levels dating to much later periods (Neolithic). Despite its Holocene age, the Darra-i-Kur specimen is, so far, the first and only ancient human from Afghanistan whose DNA has been sequenced.
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http://dx.doi.org/10.1016/j.jhevol.2017.03.003DOI Listing
June 2017

Low trabecular bone density in recent sedentary modern humans.

Am J Phys Anthropol 2017 03 19;162(3):550-560. Epub 2017 Jan 19.

Department of Anthropology, Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, 20013.

Objectives: Research on a limited number of samples suggests that trabecular bone density (i.e., bone volume fraction, BVF) within specific articulations is lower among more sedentary Holocene agricultural populations compared with Holocene foragers, implying that activity levels have a significant effect on trabecular BVF. However, it is unclear to what extent BVF differs among groups with varying activity levels and how general this phenomenon is across multiple limb articulations. Here, we test two hypotheses that: (i) sedentary populations have lower BVF compared with active populations across limb articulations; and (ii) these declines are more uniform in the lower limb (because of its more direct relationship to mobility), and more variable in the upper limb.

Materials And Methods: We estimated BVF in seven lower and upper limb articulations of five Holocene population samples with subsistence strategies spanning from foraging through horticultural to industrial using pQCT (peripheral Quantitative Computed Tomography).

Results: Both hypotheses are largely supported. First, the most active groups have significantly greater BVF in most limb elements compared with more sedentary groups. Second, all sedentary groups have relatively similar (and lower) BVF in the lower limb but show more variation in upper limb articulations.

Conclusions: These results suggest that a decline in activity levels associated with the adoption of agriculture and industrialization significantly contributed to the reduction in BVF in recent modern humans, but specific behavioral changes, particularly in the upper limb, also affected these patterns.
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http://dx.doi.org/10.1002/ajpa.23138DOI Listing
March 2017

Holocene shifts in the assembly of plant and animal communities implicate human impacts.

Nature 2016 Jan 16;529(7584):80-3. Epub 2015 Dec 16.

Department of Biology, University of Vermont, Burlington, Vermont 05405, USA.

Understanding how ecological communities are organized and how they change through time is critical to predicting the effects of climate change. Recent work documenting the co-occurrence structure of modern communities found that most significant species pairs co-occur less frequently than would be expected by chance. However, little is known about how co-occurrence structure changes through time. Here we evaluate changes in plant and animal community organization over geological time by quantifying the co-occurrence structure of 359,896 unique taxon pairs in 80 assemblages spanning the past 300 million years. Co-occurrences of most taxon pairs were statistically random, but a significant fraction were spatially aggregated or segregated. Aggregated pairs dominated from the Carboniferous period (307 million years ago) to the early Holocene epoch (11,700 years before present), when there was a pronounced shift to more segregated pairs, a trend that continues in modern assemblages. The shift began during the Holocene and coincided with increasing human population size and the spread of agriculture in North America. Before the shift, an average of 64% of significant pairs were aggregated; after the shift, the average dropped to 37%. The organization of modern and late Holocene plant and animal assemblages differs fundamentally from that of assemblages over the past 300 million years that predate the large-scale impacts of humans. Our results suggest that the rules governing the assembly of communities have recently been changed by human activity.
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http://dx.doi.org/10.1038/nature16447DOI Listing
January 2016

Alternating high and low climate variability: The context of natural selection and speciation in Plio-Pleistocene hominin evolution.

J Hum Evol 2015 Oct 25;87:5-20. Epub 2015 Aug 25.

School of Social Science, Archaeology Program, University of Queensland, Brisbane, QLD 4072, Australia.

Interaction of orbital insolation cycles defines a predictive model of alternating phases of high- and low-climate variability for tropical East Africa over the past 5 million years. This model, which is described in terms of climate variability stages, implies repeated increases in landscape/resource instability and intervening periods of stability in East Africa. It predicts eight prolonged (>192 kyr) eras of intensified habitat instability (high variability stages) in which hominin evolutionary innovations are likely to have occurred, potentially by variability selection. The prediction that repeated shifts toward high climate variability affected paleoenvironments and evolution is tested in three ways. In the first test, deep-sea records of northeast African terrigenous dust flux (Sites 721/722) and eastern Mediterranean sapropels (Site 967A) show increased and decreased variability in concert with predicted shifts in climate variability. These regional measurements of climate dynamics are complemented by stratigraphic observations in five basins with lengthy stratigraphic and paleoenvironmental records: the mid-Pleistocene Olorgesailie Basin, the Plio-Pleistocene Turkana and Olduvai Basins, and the Pliocene Tugen Hills sequence and Hadar Basin--all of which show that highly variable landscapes inhabited by hominin populations were indeed concentrated in predicted stages of prolonged high climate variability. Second, stringent null-model tests demonstrate a significant association of currently known first and last appearance datums (FADs and LADs) of the major hominin lineages, suites of technological behaviors, and dispersal events with the predicted intervals of prolonged high climate variability. Palynological study in the Nihewan Basin, China, provides a third test, which shows the occupation of highly diverse habitats in eastern Asia, consistent with the predicted increase in adaptability in dispersing Oldowan hominins. Integration of fossil, archeological, sedimentary, and paleolandscape evidence illustrates the potential influence of prolonged high variability on the origin and spread of critical adaptations and lineages in the evolution of Homo. The growing body of data concerning environmental dynamics supports the idea that the evolution of adaptability in response to climate and overall ecological instability represents a unifying theme in hominin evolutionary history.
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http://dx.doi.org/10.1016/j.jhevol.2015.06.014DOI Listing
October 2015

Intrinsic religiousness and spirituality as predictors of mental health and positive psychological functioning in Latter-Day Saint adolescents and young adults.

J Relig Health 2015 Jun;54(3):871-87

Brigham Young University, 340 MCKB, Provo, UT, 84602, USA,

We investigated the relationships between religiousness and spirituality and various indicators of mental health and positive psychosocial functioning in three separate samples of college students. A total of 898 students at Brigham Young University participated in the three studies. The students ranged in age from 17 to 26 years old, with the average age of 20.9 across all three samples. Our results indicate that intrinsic religiousness, spiritual maturity, and self-transcendence were significantly predictive of better mental health and positive functioning, including lower levels of depression, anxiety, and obsessive-compulsiveness, and higher levels of global self-esteem, identity integration, moral self-approval, and meaning in life. Intrinsic religiousness was not predictive of shame, perfectionism, and eating disorder symptoms. These findings are consistent with many prior studies that have found religiousness and spirituality to be positively associated with better mental health and positive psychosocial functioning in adolescents and young adults.
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http://dx.doi.org/10.1007/s10943-015-0043-4DOI Listing
June 2015

Human evolution. Evolution of early Homo: an integrated biological perspective.

Science 2014 Jul;345(6192):1236828

Wenner-Gren Foundation, 470 Park Avenue South, 8th Floor, New York, NY 10016, USA. E-mail:

Integration of evidence over the past decade has revised understandings about the major adaptations underlying the origin and early evolution of the genus Homo. Many features associated with Homo sapiens, including our large linear bodies, elongated hind limbs, large energy-expensive brains, reduced sexual dimorphism, increased carnivory, and unique life history traits, were once thought to have evolved near the origin of the genus in response to heightened aridity and open habitats in Africa. However, recent analyses of fossil, archaeological, and environmental data indicate that such traits did not arise as a single package. Instead, some arose substantially earlier and some later than previously thought. From ~2.5 to 1.5 million years ago, three lineages of early Homo evolved in a context of habitat instability and fragmentation on seasonal, intergenerational, and evolutionary time scales. These contexts gave a selective advantage to traits, such as dietary flexibility and larger body size, that facilitated survival in shifting environments.
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http://dx.doi.org/10.1126/science.1236828DOI Listing
July 2014

Old stones' song: use-wear experiments and analysis of the Oldowan quartz and quartzite assemblage from Kanjera South (Kenya).

J Hum Evol 2014 Jul 14;72:10-25. Epub 2014 Apr 14.

Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA; Palaeontology Section, Earth Sciences Department, National Museums of Kenya, Box 40658, Nairobi, Kenya. Electronic address:

Evidence of Oldowan tools by ∼2.6 million years ago (Ma) may signal a major adaptive shift in hominin evolution. While tool-dependent butchery of large mammals was important by at least 2.0 Ma, the use of artifacts for tasks other than faunal processing has been difficult to diagnose. Here we report on use-wear analysis of ∼2.0 Ma quartz and quartzite artifacts from Kanjera South, Kenya. A use-wear framework that links processing of specific materials and tool motions to their resultant use-wear patterns was developed. A blind test was then carried out to assess and improve the efficacy of this experimental use-wear framework, which was then applied to the analysis of 62 Oldowan artifacts from Kanjera South. Use-wear on a total of 23 artifact edges was attributed to the processing of specific materials. Use-wear on seven edges (30%) was attributed to animal tissue processing, corroborating zooarchaeological evidence for butchery at the site. Use-wear on 16 edges (70%) was attributed to the processing of plant tissues, including wood, grit-covered plant tissues that we interpret as underground storage organs (USOs), and stems of grass or sedges. These results expand our knowledge of the suite of behaviours carried out in the vicinity of Kanjera South to include the processing of materials that would be 'invisible' using standard archaeological methods. Wood cutting and scraping may represent the production and/or maintenance of wooden tools. Use-wear related to USO processing extends the archaeological evidence for hominin acquisition and consumption of this resource by over 1.5 Ma. Cutting of grasses, sedges or reeds may be related to a subsistence task (e.g., grass seed harvesting, cutting out papyrus culm for consumption) and/or a non-subsistence related task (e.g., production of 'twine,' simple carrying devices, or bedding). These results highlight the adaptive significance of lithic technology for hominins at Kanjera.
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http://dx.doi.org/10.1016/j.jhevol.2014.03.002DOI Listing
July 2014

Understanding patient satisfaction ratings for radiology services.

AJR Am J Roentgenol 2013 Dec;201(6):1190-5; quiz 1196

1 Hypnalgesics, LLC, 157 Ivy St, Brookline, MA 02446.

Objective: Under the Hospital Value-Based Purchasing Program of the Centers for Medicare & Medicaid Services, patient satisfaction accounts for 30% of the measures of and payments for quality of care. Understanding what drives patient satisfaction data and how the data are obtained, converted into scores, and formulated into rankings is increasingly critical for imaging departments. The objectives of this article are to describe the potential impact of patient satisfaction ratings on institutions and individuals, explain how patient satisfaction is rated and ranked, identify drivers that affect the ratings and rankings, and probe the resulting challenges unique to radiology departments.

Conclusion: Research results indicate that training providers to make simple modifications in their language and behavior during patient care can significantly impact patient satisfaction, which, in turn, can impact both quality-of-care ratings and the bottom line of hospitals. Training providers is a simple and cost-effective way to potentiate the clinical expression of compassion into improvement of patient satisfaction and financial reward, a national trend that no one in the game can afford to ignore.
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http://dx.doi.org/10.2214/AJR.13.11281DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4427188PMC
December 2013

Earliest archaeological evidence of persistent hominin carnivory.

PLoS One 2013 25;8(4):e62174. Epub 2013 Apr 25.

Department of Anthropology and Institute of Archaeology, Baylor University, Waco, Texas, USA.

The emergence of lithic technology by ≈ 2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ≈ 1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to 2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence - spanning hundreds to thousands of years - and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0062174PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3636145PMC
November 2013

Evolution: Big brains explained.

Authors:
Richard Potts

Nature 2011 Nov 30;480(7375):43-4. Epub 2011 Nov 30.

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http://dx.doi.org/10.1038/480043aDOI Listing
November 2011

Multicenter, double-blind, randomized, placebo-controlled, parallel-group study of the efficacy, safety, and tolerability of THC:CBD extract and THC extract in patients with intractable cancer-related pain.

J Pain Symptom Manage 2010 Feb 5;39(2):167-79. Epub 2009 Nov 5.

Severn Hospice, Shrewsbury, Shropshire, United Kingdom.

This study compared the efficacy of a tetrahydrocannabinol:cannabidiol (THC:CBD) extract, a nonopioid analgesic endocannabinoid system modulator, and a THC extract, with placebo, in relieving pain in patients with advanced cancer. In total, 177 patients with cancer pain, who experienced inadequate analgesia despite chronic opioid dosing, entered a two-week, multicenter, double-blind, randomized, placebo-controlled, parallel-group trial. Patients were randomized to THC:CBD extract (n = 60), THC extract (n = 58), or placebo (n = 59). The primary analysis of change from baseline in mean pain Numerical Rating Scale (NRS) score was statistically significantly in favor of THC:CBD compared with placebo (improvement of -1.37 vs. -0.69), whereas the THC group showed a nonsignificant change (-1.01 vs. -0.69). Twice as many patients taking THC:CBD showed a reduction of more than 30% from baseline pain NRS score when compared with placebo (23 [43%] vs. 12 [21%]). The associated odds ratio was statistically significant, whereas the number of THC group responders was similar to placebo (12 [23%] vs. 12 [21%]) and did not reach statistical significance. There was no change from baseline in median dose of opioid background medication or mean number of doses of breakthrough medication across treatment groups. No significant group differences were found in the NRS sleep quality or nausea scores or the pain control assessment. However, the results from the European Organisation for Research and Treatment of Cancer Quality of Life Cancer Questionnaire showed a worsening in nausea and vomiting with THC:CBD compared with placebo (P = 0.02), whereas THC had no difference (P = 1.0). Most drug-related adverse events were mild/moderate in severity. This study shows that THC:CBD extract is efficacious for relief of pain in patients with advanced cancer pain not fully relieved by strong opioids.
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http://dx.doi.org/10.1016/j.jpainsymman.2009.06.008DOI Listing
February 2010

Oldest evidence of tool making hominins in a grassland-dominated ecosystem.

PLoS One 2009 Oct 21;4(9):e7199. Epub 2009 Oct 21.

Department of Anthropology, Queens College and NYCEP, Flushing, New York, USA.

Background: Major biological and cultural innovations in late Pliocene hominin evolution are frequently linked to the spread or fluctuating presence of C(4) grass in African ecosystems. Whereas the deep sea record of global climatic change provides indirect evidence for an increase in C(4) vegetation with a shift towards a cooler, drier and more variable global climatic regime beginning approximately 3 million years ago (Ma), evidence for grassland-dominated ecosystems in continental Africa and hominin activities within such ecosystems have been lacking.

Methodology/principal Findings: We report stable isotopic analyses of pedogenic carbonates and ungulate enamel, as well as faunal data from approximately 2.0 Ma archeological occurrences at Kanjera South, Kenya. These document repeated hominin activities within a grassland-dominated ecosystem.

Conclusions/significance: These data demonstrate what hitherto had been speculated based on indirect evidence: that grassland-dominated ecosystems did in fact exist during the Plio-Pleistocene, and that early Homo was active in open settings. Comparison with other Oldowan occurrences indicates that by 2.0 Ma hominins, almost certainly of the genus Homo, used a broad spectrum of habitats in East Africa, from open grassland to riparian forest. This strongly contrasts with the habitat usage of Australopithecus, and may signal an important shift in hominin landscape usage.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0007199PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2746317PMC
October 2009

Clients' perceptions of how reorientation therapy and self-help can promote changes in sexual orientation.

Psychol Rep 2008 Feb;102(1):3-28

Department of Family and Preventive Medicine, University of Utah School of Medicine, 375 Chipeta Way, Salt Lake City, UT 84108, USA.

Presented is a summary of 882 homosexual people's responses to 5 open-ended questions about sexual reorientation therapy. Of the 882 participants, 726 reported that they had received reorientation therapy from a professional therapist or a pastoral counselor. As a group, 779 (89.7%) of the participants viewed themselves as "more homosexual than heterosexual," "almost exclusively homosexual," or "exclusively homosexual" in their orientation before receiving reorientation therapy or making self-help efforts to change. The majority reported they believed sexual reorientation therapy and various forms of self-help were helpful to them, psychologically, spiritually, and sexually.
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http://dx.doi.org/10.2466/pr0.102.1.3-28DOI Listing
February 2008

Killing of Brucella antigen-sensitized macrophages by T lymphocytes in bovine brucellosis.

Vet Immunol Immunopathol 2007 Dec 11;120(3-4):148-59. Epub 2007 Aug 11.

Center for Veterinary Health Sciences, Department of Veterinary Pathobiology, 250 McElroy Hall, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078-2007, USA.

The present study was an investigation into the role of T lymphocytes in the killing of antigen-sensitized macrophages (M Phi) in bovine brucellosis. Following confirmation of bovine T lymphocyte cell lines derived from Brucella abortus Strain 19 vaccinated steers as antigen-specific in proliferation studies using various antigens, we adapted an apoptosis assay for evaluation of cytotoxicity by these bovine T cells against autologous monocyte-derived macrophages (MDM Phi) as target cells. Various B. abortus antigen preparations were tested including whole gamma-irradiated B. abortus bacteria (gamma BA), a soluble cytosolic protein fraction and a membrane-associated protein fraction. Both polyclonal and cloned T lymphocyte cell lines exhibited cytotoxicity against MDM Phi targets in an antigen-specific fashion. Polyclonal and cloned T lymphocyte cell lines demonstrated cytotoxic responses to varying degrees against B. abortus antigens regardless of whether the antigen used was whole nonviable bacteria, a soluble protein extract or a membrane-associated fraction of extracted bacteria. To further develop correlation of these responses to an in vivo host defense mechanism, cytotoxicity was evaluated using target cells that had been infected with live B. abortus S19 or B. abortus Strain 2308. Cytotoxic responses were also demonstrated consistently against infected targets with either strain of B. abortus although in most cases, cytotoxicity was higher against target cells sensitized with gamma BA compared to those infected with live bacteria. Cloned T lymphocyte cell lines were all CD4+, CD8(-) cells indicating that the observed cytotoxic responses were most likely due to an inflammatory Th1 response and may represent an important host defense mechanism induced by vaccination with live attenuated strains of B. abortus in cattle.
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http://dx.doi.org/10.1016/j.vetimm.2007.08.004DOI Listing
December 2007

Sequence of mammalian fossils, including hominoid teeth, from the Bubing Basin caves, South China.

J Hum Evol 2007 Apr 11;52(4):370-9. Epub 2006 Nov 11.

Faculty of Earth Sciences, China University of Geoscience, Wuhan, 430074, PR China.

A Plio-Pleistocene to Holocene faunal sequence has been recovered from four carefully excavated caves in the Bubing Basin, adjacent to the larger Bose Basin of South China. The caves vary in elevation; we suggest that the higher caves were formed and filled with sediments prior to the lower caves. The highest deposits, which are from Mohui Cave, contain hominoid teeth and other fossilized remains of mammalian taxa most similar to late Pliocene and early Pleistocene faunas. Wuyun Cave ( approximately 50m lower in elevation than Mohui) contains a late middle Pleistocene fauna, which is supported by U-series age constraints from 350 to 200ka. Lower Pubu Cave ( approximately 23m below Wuyun) is assigned to the late Pleistocene, while the Cunkong Cave (the lowest, approximately 2m lower elevation than Lower Pubu) preserves a Holocene fauna. The four faunal assemblages indicate species-level changes in Ailuropoda, Stegodon, and Sus, the appearance of Elephas, the local disappearance of Stegodon, and the migration of Equus hemionus to South China. These initial results of our work call into question the continued value of the Stegodon/Ailuropoda Fauna, a category long used to characterize the Pleistocene faunas of South China. Excavation of karstic caves of varying elevation within the basins of South China holds promise for defining local sequences of mammalian fossils that can be used to investigate faunal variations related to climate change, biogeographic events, and evolutionary change over the past two million years. Stable isotopic analysis of a small sample of mammalian teeth from Bubing Basin caves is consistent with 100% C(3) vegetation in the Bubing/Bose region, with certain delta(13)C values consistent with a canopied woodland or forest. A preliminary assessment of the hominoid teeth indicates the presence of diverse molar and premolar morphologies including dental remains of Gigantopithecus blacki and a sample with similarities to the teeth reported from Longgupo.
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http://dx.doi.org/10.1016/j.jhevol.2006.10.003DOI Listing
April 2007

Small mid-Pleistocene hominin associated with East African Acheulean technology.

Science 2004 Jul;305(5680):75-8

Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560-0112, USA.

Hominin fossils from the African mid-Pleistocene are rare despite abundant Acheulean tools in Africa and apparently African-derived hominins in Eurasia between 1.0 and 0.5 million years ago (Ma). Here we describe an African fossil cranium constrained by 40Ar/39Ar analyses, magnetostratigraphy, and sedimentary features to 0.97 to 0.90 Ma, and stratigraphically associated with Acheulean handaxes. Although the cranium represents possibly the smallest adult or near-adult known between 1.7 and 0.5 Ma, it retains features observed in larger Homo erectus individuals, yet shows a distinct suite of traits indicative of wide population variation in the hominins of this period.
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http://dx.doi.org/10.1126/science.1097661DOI Listing
July 2004

Paleoenvironmental basis of cognitive evolution in great apes.

Authors:
Richard Potts

Am J Primatol 2004 Mar;62(3):209-28

Human Origins Program, National Museum of Natural History, Smithsonian Institution, D.C., USA.

A bias favoring tree-dominated habitats and ripe-fruit frugivory has persisted in great ape evolution since the early Miocene. This bias is indicated by fossil ape paleoenvironments, molar morphology, dental microwear, the geographic pattern of extinctions, and extant apes' reliance on wooded settings. The ephemeral aspect of high-quality fruit has placed a premium on cognitive and social means of finding and defending food sources, and appears related to great apes' affinity since the Miocene for wooded, fruit-rich environments. These habitats have, however, undergone a severe withdrawal toward the low latitudes of Africa and Southeast Asia since the late Miocene, corresponding to a decline in the diversity of great apes beginning 9.5 million years ago. Plio-Pleistocene records imply that wooded settings of Africa and SE Asia were prone to substantial fragmentation and coalescence. Once apes were confined to equatorial settings, therefore, habitat instability heightened the spatial/temporal uncertainty of ripe-fruit sources. Prolonged learning, the assignment of attributes to distant places, mental representation, and reliance on fallback foods were all favored in this dynamic environmental context. These abilities helped sustain forest frugivory in most lineages. Fluid social grouping afforded the animals opportunities to locate ephemeral foods in continuous and fragmented forests. Fission-fusion grouping also magnified the problems of object impermanence (of individuals) and dispersion manifested by food sources in the ecological realm. Thus the spatial and temporal dynamics of fruit and wooded habitats since the Miocene are reflected in important components of great ape cognition, foraging, and sociality. In contrast to great apes, cercopithecoid monkeys have increased their plant dietary options and diversified in seasonal environments since the late Miocene. Early hominins eventually severed the habitat bias that characterized the evolution of great apes, and later expanded into diverse environments.
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http://dx.doi.org/10.1002/ajp.20016DOI Listing
March 2004

An inquiry-based approach to teaching research design: asking the right questions.

Psychol Rep 2002 Jun;90(3 Pt 2):1064-8

Oklahoma State University, Stillwater 74078, USA.

To describe an inquiry-based learning activity and discuss the advantages of using such activities to demonstrate research design to undergraduate psychology students the authors presented students with the research problem of eyewitness memory recall and asked students to solve the problem, using the information provided by the course. Working in small groups, students reviewed eyewitness studies and designed their own research materials, including a videotaped theft and a CD-ROM version of the eyewitness survey and potential suspect line-up. Poststudy interviews showed that the students enjoyed the activity and felt that they had a better understanding of experimental research design than they had before the exercise. It is proposed that this activity may be a useful hands-on tool for instructors who have difficulty teaching students fundamental topics such as literature reviews, hypothesis testing, reliability and validity of research measures, and experimental design.
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http://dx.doi.org/10.2466/pr0.2002.90.3c.1064DOI Listing
June 2002