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Field DL, Broadhurst LM, Elliott CP, Young AG. Population assignment in autopolyploids. Heredity (Edinb) 2017; 119:389-401. [PMID: 28976495 DOI: 10.1038/hdy.2017.51] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 07/07/2017] [Accepted: 07/24/2017] [Indexed: 11/09/2022] Open
Abstract
Understanding the patterns of contemporary gene dispersal within and among populations is of critical importance to population genetics and in managing populations for conservation. In contrast to diploids, there are few studies of gene dispersal in autopolyploids, in part due to complex polysomic inheritance and genotype ambiguity. Here we develop a novel approach for population assignment for codominant markers for autotetraploids and autohexaploids. This method accounts for polysomic inheritance, unreduced gametes and unknown allele dosage. It can also utilise information regarding the origin and genotype of one parent for population assignment of maternal or paternal parents. Using simulations, we demonstrate that our approach achieves high levels of accuracy for assignment even when population divergence is low (FST~0.06) and with only 12 microsatellite loci. We also show that substantially higher accuracy is achieved when known maternal information is utilised, regardless of whether allele dosage is known. Although this novel method exhibited near identical levels of accuracy to Structure when population divergence was high, it performed substantially better for most parameters at moderate (FST=0.06) to low levels of divergence (FST=0.03). These methods fill an important gap in the toolset for autopolyploids and pave the way for investigating contemporary gene dispersal in a widespread group of organisms.
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Affiliation(s)
- D L Field
- Department of Botany and Biodiversity Research, University of Vienna, Faculty of Life Sciences, Vienna, Austria
| | | | - C P Elliott
- Biodiversity Conservation Centre, Kings Park, Western Australia, Australia
| | - A G Young
- CSIRO Plant Industry, Canberra, ACT, Australia
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Young AG. Risky resources: Household production, food contamination, and perceptions of aflatoxin exposure among Zambian female farmers. Economic Anthropology 2017. [DOI: 10.1002/sea2.12088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Alyson G. Young
- Department of Anthropology; University of Florida; Gainesville FL 32611 USA
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Collings P, Marten MG, Pearce T, Young AG. Country food sharing networks, household structure, and implications for understanding food insecurity in Arctic Canada. Ecol Food Nutr 2015; 55:30-49. [PMID: 26595315 DOI: 10.1080/03670244.2015.1072812] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
We examine the cultural context of food insecurity among Inuit in Ulukhaktok, Northwest Territories, Canada. An analysis of the social network of country food exchanges among 122 households in the settlement reveals that a household's betweenness centrality-a measure of brokerage-in the country food network is predicted by the age of the household. The households of married couples were better positioned within the sharing network than were the households of single females or single males. Households with an active hunter or elder were also better positioned in the network. The households of single men and women appear to experience limited access to country food, a considerable problem given the increasing number of single-adult households over time. We conclude that the differences between how single women and single men experience constrained access to country foods may partially account for previous findings that single women in arctic settlements appear to be at particular risk for food insecurity.
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Affiliation(s)
- Peter Collings
- a Department of Anthropology , University of Florida , Florida , USA
| | - Meredith G Marten
- a Department of Anthropology , University of Florida , Florida , USA
| | - Tristan Pearce
- b University of the Sunshine Coast , Sippy Downs , Australia
| | - Alyson G Young
- c Department of Anthropology , University of Florida , Florida , USA
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Pickup M, Field DL, Rowell DM, Young AG. Source population characteristics affect heterosis following genetic rescue of fragmented plant populations. Proc Biol Sci 2013; 280:20122058. [PMID: 23173202 DOI: 10.1098/rspb.2012.2058] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Understanding the relative importance of heterosis and outbreeding depression over multiple generations is a key question in evolutionary biology and is essential for identifying appropriate genetic sources for population and ecosystem restoration. Here we use 2455 experimental crosses between 12 population pairs of the rare perennial plant Rutidosis leptorrhynchoides (Asteraceae) to investigate the multi-generational (F(1), F(2), F(3)) fitness outcomes of inter-population hybridization. We detected no evidence of outbreeding depression, with inter-population hybrids and backcrosses showing either similar fitness or significant heterosis for fitness components across the three generations. Variation in heterosis among population pairs was best explained by characteristics of the foreign source or home population, and was greatest when the source population was large, with high genetic diversity and low inbreeding, and the home population was small and inbred. Our results indicate that the primary consideration for maximizing progeny fitness following population augmentation or restoration is the use of seed from large, genetically diverse populations.
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Affiliation(s)
- M Pickup
- CSIRO Plant Industry, GPO Box 1600, Canberra, Australian Capital Territory, 2601, Australia.
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Abstract
Food preferences during pregnancy result from a complex set of biocultural interactions with important implications for maternal and child health. This article explores the social context of maternal food choice in marginal environments of East Africa. Biocultural data collected among Turkana and Datoga women living in Kenya and Tanzania indicate there is a significant social context to food choice that influences the types of food that women report craving and the food that is consumed. Our framework argues for a deeper understanding of how culture shapes food preferences and how marginalization can constrain access to favored and healthy foods.
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Affiliation(s)
- Alyson G Young
- Department of Anthropology, University of Florida, Gainesville, Florida 32611, USA.
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Field DL, Ayre DJ, Whelan RJ, Young AG. Patterns of hybridization and asymmetrical gene flow in hybrid zones of the rare Eucalyptus aggregata and common E. rubida. Heredity (Edinb) 2011; 106:841-53. [PMID: 21063438 PMCID: PMC3186239 DOI: 10.1038/hdy.2010.127] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 08/17/2010] [Accepted: 09/06/2010] [Indexed: 11/09/2022] Open
Abstract
The patterns of hybridization and asymmetrical gene flow among species are important for understanding the processes that maintain distinct species. We examined the potential for asymmetrical gene flow in sympatric populations of Eucalyptus aggregata and Eucalyptus rubida, both long-lived trees of southern Australia. A total of 421 adults from three hybrid zones were genotyped with six microsatellite markers. We used genealogical assignments, admixture analysis and analyses of spatial genetic structure and spatial distribution of individuals, to assess patterns of interspecific gene flow within populations. A high number of admixed individuals were detected (13.9-40% of individuals), with hybrid populations consisting of F(1) and F(2) hybrids and backcrosses in both parental directions. Across the three sites, admixture proportions were skewed towards the E. aggregata genetic cluster (x=0.56-0.65), indicating that backcrossing towards E. aggregata is more frequent. Estimates of long-term migration rates also indicate asymmetric gene flow, with higher migration rates from E. aggregata to hybrids compared with E. rubida. Taken together, these results indicate a greater genetic input from E. aggregata into the hybrid populations. This asymmetry probably reflects differences in style lengths (E. rubida: ~7 mm, E. aggregata: ~4 mm), which can prevent pollen tubes of smaller-flowered species from fertilizing larger-flowered species. However, analyses of fine-scale genetic structure suggest that localized seed dispersal (<40 m) and greater clustering between hybrid and E. aggregata individuals may also contribute to directional gene flow. Our study highlights that floral traits and the spatial distributions of individuals can be useful predictors of the directionality of interspecific gene flow in plant populations.
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Affiliation(s)
- D L Field
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Ontario, Canada.
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Merenstein D, Gonzalez J, Young AG, Roberts RF, Sanders ME, Petterson S. Study to investigate the potential of probiotics in children attending school. Eur J Clin Nutr 2011; 65:447-53. [DOI: 10.1038/ejcn.2010.290] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Pickup M, Young AG. Population size, self-incompatibility and genetic rescue in diploid and tetraploid races of Rutidosis leptorrhynchoides (Asteraceae). Heredity (Edinb) 2007; 100:268-74. [DOI: 10.1038/sj.hdy.6801070] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Hoebee SE, Young AG. Low neighbourhood size and high interpopulation differentiation in the endangered shrub Grevillea iaspicula McGill (Proteaceae). Heredity (Edinb) 2001; 86:489-96. [PMID: 11520349 DOI: 10.1046/j.1365-2540.2001.00857.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mating system parameters and genetic diversity were examined for five populations of the endangered shrub Grevillea iaspicula (Proteaceae). Controlled pollinations show that G. iaspicula has an effective self-incompatibility system and little potential for agamospermy. This is reflected in uniformly high multilocus outcrossing rates (tm=0.96-1.00). However, average paternal diversity within open-pollinated sibships is low (rp=0.31-0.54), suggesting that mating within populations is quite restricted. Despite the small size of most populations (four of the five populations studied have fewer than 20 reproductive individuals) the species still possesses moderate to high allelic richness (A=1.6-2.5). Interpopulation genetic differentiation is high (D=0.04-0.32), suggesting that gene flow is limited, even among populations separated by only a few kilometres.
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Affiliation(s)
- S E Hoebee
- Centre for Plant Biodiversity Research, CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia.
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Schmidt-Adam G, Young AG, Murray BG. Low outcrossing rates and shift in pollinators in New Zealand pohutukawa (Metrosideros excelsa; Myrtaceae). Am J Bot 2000; 87:1265-1271. [PMID: 10991897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
New Zealand pohutukawa (Metrosideros excelsa), a member of the Myrtaceae, is a large, mass-flowering tree endemic to northern New Zealand coastlines. Mainland populations have been reduced to fragmented stands, and the original suite of bird pollinators has been largely replaced by introduced species. The native pollinator fauna on several offshore islands is largely intact and includes three species of the New Zealand honeyeaters (Meliphagidae) and native, solitary bees. We estimated multilocus outcrossing rates for three mainland and two island populations and found that they were among the lowest in the Myrtaceae (t(m) = 0.22-0.53). The shift in pollinators had no measurable effect on the mating system. Mass-flowering facilitates geitonogamous selfing, and inbreeding depression in seedling height was detectable at 6 mo of growth. F(s) [Wright's (1965) Fixation Index] was consistently higher than F(m) in all populations, indicating that selection may eliminate selfed offspring from populations prior to achieving reproductive maturity. Results suggest that increased selfing in mainland populations due to pollinator changes is not responsible for current patterns of poor regeneration of this species.
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Affiliation(s)
- G Schmidt-Adam
- School of Biological Sciences, The University of Auckland, Private Bag 92019 Auckland, New Zealand; and
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Brown AH, Young AG. Genetic diversity in tetraploid populations of the endangered daisy Rutidosis leptorrhynchoides and implications for its conservation. Heredity (Edinb) 2000; 85 ( Pt 2):122-9. [PMID: 11012713 DOI: 10.1046/j.1365-2540.2000.00742.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polyploidy is an important variable in assessing the genetics of endangered plant species. Species consisting of populations with different chromosome numbers pose questions as to the mode of inheritance, relative variability status, population divergence and gene flow. The self-incompatible species Rutidosis leptorrhynchoides (Asteraceae) in south-eastern Australia is a good example. The remnant populations in the northern sector of the species range are diploid, whereas southern ones are either diploid or tetraploid. Allozyme analysis of the tetraploid populations showed tetrasomic inheritance confirming an autopolyploid genetic system, a modest increase in their allelic richness over diploid populations in the same region and a lack of genetic divergence. Conservation and replenishment strategies should take account of these genetic features of mixed ploidy.
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Affiliation(s)
- A H Brown
- Centre for Plant Biodiversity Research, CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia.
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Young AG, Brown AHD. Comparative analysis of the mating system of the rare woodland shrub Daviesia suaveolens and its common congener D. mimosoides. Heredity (Edinb) 1998. [DOI: 10.1046/j.1365-2540.1998.00304.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Young AG, Merriam HG, Warwick SI. The effects of forest fragmentation on genetic variation in Acer saccharum Marsh. (sugar maple) populations. Heredity (Edinb) 1993. [DOI: 10.1038/hdy.1993.136] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Young AG. Points from letters: Management of appendicitis. West J Med 1976. [DOI: 10.1136/bmj.2.6045.1201-e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Uhl CN, Young AG. Resistance to extinction as a function of incentive, percentage of reinforcement, and number of nonreinforced trials. J Exp Psychol 1967; 73:556-64. [PMID: 6034010 DOI: 10.1037/h0024389] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Young AG. Resistance to extinction as a function of number of nonreinforced trials and effortfulness of response. J Exp Psychol 1966; 72:610-3. [PMID: 5969737 DOI: 10.1037/h0023796] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Young AG. Control of the Minor Infectious Diseases. Public Health Pap Rep 1907; 33:50-52. [PMID: 19601376 PMCID: PMC2232453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Wilbur CL, Chapin CV, Young AG, Bracken HM, Fulton JS. Report of the Committee on Demography and Statistics in Their Sanitary Relation. Public Health Pap Rep 1899; 25:337-352. [PMID: 19600892 PMCID: PMC2329504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Young AG. Formaldehyd as a Milk Preservative. Public Health Pap Rep 1899; 25:136-144. [PMID: 19600862 PMCID: PMC2329554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Wilbur CL, Monjarás JE, Pelletier E, Young AG, Lewis RH. Report of the Committee on the Nomenclature of Diseases and Forms of Statistics. Public Health Pap Rep 1897; 23:337-340. [PMID: 19600780 PMCID: PMC2330008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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