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4. Variation in selection and its evolutionary consequences

Author

Hunter, Darren Clarke and Morrissey, Michael Blair

Subjects
576.8
Abstract

It is widely appreciated that many aspects of selection change temporally when populations experience stochastic environments. However, the long term consequences for adaptive evolution has received less consideration. The availability of long term data, including phenotypic and life history information, along with high quality pedigrees, allows old approaches and theoretical ideas to be re-considered, and applied, empirically. To investigate viability selection in a wild population of Soay sheep (Ovis aries) I estimated the sensitivity of selection to changes in population size. Using environmentally structured fitness functions I investigated pathways through which changes in population size drive changes in selection estimates. Much of the observed variation in selection was driven by changes in mean fitness. If generally true in other populations this may have important consequences regarding the occurrence of fluctuating selection. I then developed a method to estimate both individual, and cohort, success using theory based around Fisher's reproductive value. This approach overcomes some complications associated with overlapping generations and age structure common in natural populations. Using pedigree information I tracked relative contributions to the future population through time and additionally used alternative theory from demographic literature to calculate stochastic total cohort reproductive values. The different estimates corresponded closely. Finally, I weighted selection differentials by measures of cohort reproductive success. When generations overlap, correctly considering the contribution a cohort makes to the future population can greatly reduce the expected response, as cohorts that experience stronger selection typically contribute less. This might provide one explanation for the paradox of stasis. By linking approaches from multiple different fields with high quality, long term, data, I demonstrate that ecological pathways that influence selection can be identified, providing greater understanding of longer term evolutionary dynamics. Further applications of the methods developed could generate opportunities to investigate generalities in temporal evolutionary patterns not previously considered.

Published
2019
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10. Genomic prediction in the wild: A case study in Soay sheep.

Author

Ashraf, Bilal, Hunter, Darren C., Bérénos, Camillo, Ellis, Philip A., Johnston, Susan E., Pilkington, Jill G., Pemberton, Josephine M., and Slate, Jon

Subjects
*LOCUS (Genetics), *QUANTITATIVE genetics, *MOLECULAR genetics, *SHEEP, *PLANT breeding
Abstract

Genomic prediction, the technique whereby an individual's genetic component of their phenotype is estimated from its genome, has revolutionised animal and plant breeding and medical genetics. However, despite being first introduced nearly two decades ago, it has hardly been adopted by the evolutionary genetics community studying wild organisms. Here, genomic prediction is performed on eight traits in a wild population of Soay sheep. The population has been the focus of a >30 year evolutionary ecology study and there is already considerable understanding of the genetic architecture of the focal Mendelian and quantitative traits. We show that the accuracy of genomic prediction is high for all traits, but especially those with loci of large effect segregating. Five different methods are compared, and the two methods that can accommodate zero‐effect and large‐effect loci in the same model tend to perform best. If the accuracy of genomic prediction is similar in other wild populations, then there is a real opportunity for pedigree‐free molecular quantitative genetics research to be enabled in many more wild populations; currently the literature is dominated by studies that have required decades of field data collection to generate sufficiently deep pedigrees. Finally, some of the potential applications of genomic prediction in wild populations are discussed. see also the Perspective by Richard J. A. Buggs [ABSTRACT FROM AUTHOR]

Published
2022
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16. Quantification and decomposition of environment-selection relationships

Author

Hunter, Darren C, Pemberton, Josephine M, Pilkington, Jill G, Morrissey, Michael B, The Royal Society, University of St Andrews. School of Biology, and University of St Andrews. Centre for Biological Diversity

Subjects
QH301, Phenotypic selection coefficients, Quantitative genetics, Environmental heterogeneity, Natural selection, QH301 Biology, DAS, QH426 Genetics, QH426
Abstract

The long term project on St Kilda has been largely funded by the UK Natural Environment Research Council. M. B. Morrissey is supported by a University Research Fellowship from the Royal Society (London). D. C. Hunter is funded by a PhD Scholarship from the University of St Andrews. In nature, selection varies across time in most environments, but we lack an understanding of how specific ecological changes drive this variation. Ecological factors can alter phenotypic selection coefficients through changes in trait distributions or individual mean fitness even when the trait-absolute fitness relationship remains constant. We apply and extend a regression-based approach in a population of Soay sheep (Ovis aries) and suggest unbiased metrics of environment-selection relationships that can be compared across studies. We then introduce a novel method which constructs an environmentally-structured fitness function. This allows calculation of full (as in existing approaches) and partial (acting separately through the absolute fitness function slope, mean fitness, and phenotype distribution) sensitivities of selection to an ecological variable. Both approaches show positive overall effects of density on viability selection of lamb mass. However, the second approach demonstrates that this relationship is primarily driven by effects of density on mean fitness, rather than on the trait-fitness relationship slope. If such mechanisms of environmental dependence of selection are common this could have important implications regarding the frequency of fluctuating selection, and how previous selection inferences relate to longer-term evolutionary dynamics. Postprint

Published
2018

19. The Appellate Court Declared OSHA Has No Limit on the Look-Back Period for Repeat Citations--and That's a Big Deal

Author

Hunter, Darren

Subjects
United States. Occupational Safety and Health Administration, Safety regulations, Business, Metals, metalworking and machinery industries
Abstract

The U.S. Congress created multiple classifications of citations that may be issued to employers who violate the Occupational Safety and Health Act of 1970 (OSH Act), or any regulation, standard, [...]

Published
2018

20. OSHA Takes New Approach to Safety Incentives

Author

Hunter, Darren J.

Subjects
Drug testing -- Laws, regulations and rules, Employee incentives -- Laws, regulations and rules, Occupational safety and health -- Laws, regulations and rules, Government regulation, Business, Metals, metalworking and machinery industries
Abstract

The Occupational Safety and Health Administration (OSHA) does not currently have regulations related to safety incentive programs or post-incident drug testing policies. It has nonetheless opined on the validity of [...]

Published
2018

21. Increased genetic marker density reveals high levels of admixture between red deer and introduced Japanese sika in Kintyre, Scotland.

Author

McFarlane, S. Eryn, Hunter, Darren C., Senn, Helen V., Smith, Stephanie L., Holland, Rebecca, Huisman, Jisca, and Pemberton, Josephine M.

Subjects
*RED deer, *SIKA deer, *GENETIC markers, *GENE frequency, *NUMBERS of species
Abstract

Hybridization is a natural process at species range boundaries, but increasing numbers of species are hybridizing due to direct or indirect human activities. In such cases of anthropogenic hybridization, subsequent introgression can threaten the survival of native species. To date, many such systems have been studied with too few genetic markers to assess the level of threat resulting from advanced backcrossing. Here, we use 44,999 single nucleotide polymorphisms (SNPs) and the ADMIXTURE program to study two areas of Scotland where a panel of 22 diagnostic microsatellites previously identified introgression between native red deer (Cervus elaphus) and introduced Japanese sika (Cervus nippon). In Kintyre, we reclassify 26% of deer from the pure species categories to the hybrid category whereas in the NW Highlands we only reclassify 2%. As expected, the reclassified individuals are mostly advanced backcrosses. We also investigate the ability of marker panels selected on different posterior allele frequency criteria to find hybrids assigned by the full marker set and show that in our data, ancestry informative markers (i.e. those that are highly differentiated between the species, but not fixed) are better than diagnostic markers (those markers that are fixed between the species) because they are more evenly distributed in the genome. Diagnostic loci are concentrated on the X chromosome to the detriment of autosomal coverage. [ABSTRACT FROM AUTHOR]

Published
2020
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24. The EPA's Clean Water Rule: Why Is It Controversial and Can It Be Fixed?

Author

Hunter, Darren and Rippie, Rooney

Subjects
United States. Army. Corps of Engineers, United States. Environmental Protection Agency, United States. Supreme Court, Government agencies, Business, Metals, metalworking and machinery industries
Abstract

Under the authority of the EE Clean Water Act of 1972, the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers have jurisdiction to regulate discharges and [...]

Published
2018

26. What to expect from the upcoming OSHA penalty increases

Author

Hunter, Darren J. and Higginbotham, Jason

Subjects
Safety regulations -- Interpretation and construction, Occupational safety and health -- Laws, regulations and rules, Government regulation, Business, Metals, metalworking and machinery industries, Federal Civil Penalties Inflation Adjustment Act of 1990, Occupational Safety and Health Act of 1970
Abstract

On August 1, civil penalties for violations identified by the U.S. Occupational Safety and Health Administration (OSHA) increased by 78%. The Federal Civil Penalties Inflation Adjustment Act Improvements Act of [...]

Published
2016

27. Criminal prosecution and the recent OSHA Memo

Author

Hunter, Darren J.

Subjects
Criminal liability -- Laws, regulations and rules, Scrap metals -- Safety and security measures -- Laws, regulations and rules, Occupational safety and health -- Laws, regulations and rules, Government regulation, Business, Metals, metalworking and machinery industries, Occupational Safety and Health Act of 1970
Abstract

On December 17, 2015, the U.S. Department of Labor (DOL) and the Department of Justice (DOJ) entered into a memorandum of understanding that gives the Occupational Safety and Health Administration [...]

Published
2016

28. OSHA updates hazard communication standards

Author

Hunter, Darren J.

Subjects
Somatotropin -- Standards, Occupational safety and health, Business, Metals, metalworking and machinery industries
Abstract

Much has been written about the new hazard communication standard (HCS 2012) from the U.S. Occupational Safety and Health Administration (OSHA) over the last four years. OSHA adopted HCS 2012 [...]

Published
2016

29. Simplifying OSHA's record retention requirements

Author

Hunter, Darren J.

Subjects
Employers -- Safety and security measures -- Laws, regulations and rules, Government regulation, Business, Metals, metalworking and machinery industries
Abstract

Many of the regulations from the U.S. Occupational Safety and Health Administration (OSHA) have been in effect for more than 40 years, with new regulations enacted every year. While the [...]

Published
2015

30. OSHA's heightened focus on temporary employees

Author

Hunter, Darren J.

Subjects
United States. Occupational Safety and Health Administration, Workers, Employment services, Employers, Overtime, Business, Metals, metalworking and machinery industries
Abstract

More than any time in recent history, employers rely on a stable of temporary or contract workers to perform at all levels, including highly specialized tasks. From an employment perspective, [...]

Published
2015

31. Efforts strengthen chemical safety in the workplace

Author

Hunter, Darren J.

Subjects
United States. Occupational Safety and Health Administration -- Safety and security measures -- Laws, regulations and rules, Hazardous substances -- Laws, regulations and rules, Government regulation, Business, Metals, metalworking and machinery industries
Abstract

Over the years, the U.S. Chemical Safety Board (CSB) has issued a number of recommendations directed to the Occupational Safety and Health Administration (OSHA) to strengthen its chemical safety regulations. [...]

Published
2014

32. I2P2 on back burner, but hazard assessment remains a priority for OSHA

Author

Hunter, Darren J.

Subjects
United States. Occupational Safety and Health Administration -- Planning -- Standards, Employers -- Laws, regulations and rules, Occupational health and safety -- Standards, Health risk assessment -- Usage -- Analysis -- Standards, Government regulation, Company business planning, Business, Metals, metalworking and machinery industries
Abstract

Recently, the Occupational Safety & Health Administration (OSHA) proclaimed the Injury and Illness Prevention Program (I2P2) a rulemaking priority and announced it would propose an I2P2 rulemaking by the fall [...]

Published
2014

33. I2P2: when will OSHA finally pull the trigger?

Author

Hunter, Darren J.

Subjects
Safety regulations, Employers, Business, Metals, metalworking and machinery industries
Abstract

Although the safety world has been gearing up for I2P2 for more than 30 years, very few employers have implemented full L2P2 programs. The reality is that few employers actually [...]

Published
2014

36. An Employer's Obligations to Provide First Aid.

Author

HUNTER, DARREN, RIPPIE, ROONEY, and LLP, RATNASWAMY

Subjects
EMPLOYERS, THERAPEUTICS, FIRST aid kits, WORK-related injuries
Abstract

The article offers the information on the guidance and regulations concerning the obligations of an employer to provide first aid and emergency medical treatment to its employees. The article also mentions about the United States. Occupational Safety & Health Administration(OSHA); precautions for the work related injuries.

Published
2018

37. Simplifying OSHA's Record Retention Requirements.

Author

HUNTER, DARREN J. and JAGER, MARIS

Subjects
REGULATORY reform, RECORDS retention, INDUSTRIAL safety, SAFETY standards
Abstract

The article discusses the revisions in the Occupational Safety and Health Administration (OSHA)rule. Topics include OSHA's initiative to simplify its record retention requirements which offers convenience of industries to comply with the working surface rule of OSHA, and discusses the provisions of the rule which include a simplified standards for floors, ladders, and stairways in facilities.

Published
2017

38. OSHA's Emerging Perspective on Safety Incentive Programs.

Author

HUNTER, DARREN J.

Subjects
SAFETY incentive programs, INDUSTRIAL safety, LABOR incentives, EMPLOYEE motivation
Abstract

The article discusses the different perspectives on safety incentive programs of the U.S. Occupational Safety and Health Administration (OSHA). Topics covered include the regulations of the OSHA regarding the programs, rules for rewarding workers for reporting illnesses and injuries and importance of the programs to the safety of workers. Also mentioned are details of the memorandum issued by the OSHA for employer incentives.

Published
2014

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