Papers by Elisabeth Lloyd
Biological Theory, Jul 9, 2015
This article discusses various dangers that accompany the supposedly benign methods in behavioral... more This article discusses various dangers that accompany the supposedly benign methods in behavioral evolutionary biology and evolutionary psychology that fall under the framework of ''methodological adaptationism.'' A ''Logic of Research Questions'' is proposed that aids in clarifying the reasoning problems that arise due to the framework under critique. The live, and widely practiced, ''evolutionary factors'' framework is offered as the key comparison and alternative. The article goes beyond the traditional critique of Stephen Jay Gould and Richard C. Lewontin, to present problems such as the disappearance of evidence, the mishandling of the null hypothesis, and failures in scientific reasoning, exemplified by a case from human behavioral ecology. In conclusion the paper shows that ''methodological adaptationism'' does not deserve its benign reputation.
Twin Research and Human Genetics, Aug 1, 2006
Archives of Sexual Behavior, Nov 10, 2017
The name of coauthor Kaytlin J. Renfro has been corrected since this article was originally publi... more The name of coauthor Kaytlin J. Renfro has been corrected since this article was originally published.
Archives of Sexual Behavior, Mar 4, 2017
Archives of Sexual Behavior, 2017
Most women report reliably experiencing orgasm from masturbation, but a smaller proportion of wom... more Most women report reliably experiencing orgasm from masturbation, but a smaller proportion of women report regularly experiencing orgasm from intercourse. Research suggests that concurrent clitoral stimulation during intercourse increases the likelihood of orgasm, yet most surveys of orgasm during intercourse leave unspecified whether vaginal intercourse does or does not include concurrent clitoral stimulation (assisted intercourse or unassisted intercourse, respectively). Using an online sample of 1569 men and 1478 women, we tested whether phrasing of questions about the occurrence of orgasm in intercourse modulates women's reported frequency and men's estimates of women's frequency of orgasm in intercourse. Participants provided estimatesof orgasm when asked explicitly about intercourse with stimulation unspecified, assisted intercourse, and unassisted intercourse. Women's reports of orgasm occurrence were highest in response to assisted intercourse (51-60%), second highest in response to intercourse with clitoral stimulation unspecified (31-40%), and lowest in response to unassisted intercourse (21-30%). Men's estimates of women's orgasms were highest in response to assisted intercourse (61-70%), and lowest in response to unassisted intercourse (41-50%); in both conditions, men's estimates were significantly higher than women's reports. When clitoral stimulation was unspecified, women interpreted''orgasm in intercourse''in three ways: as from intercourse alone, as including concurrent clitoral stimulation though it was unspecified, or as an average of assisted and unassisted intercourse. Taken together, these results demonstrate that the phrasing of questions about women's orgasm produces markedly different orgasm estimates, and suggest that concurrent clitoral stimulation increases the likelihood of women experiencing orgasm in intercourse. Keywords Female orgasm Á Intercourse Á Clitoral stimulation Á Masturbation Á Sex difference The name of coauthor Kaytlin J. Renfro has been corrected since this article was originally published.
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Proceedings of the National Academy of Sciences of the United States of America, Jan 15, 1993
Most analyses of species selection require emergent, as opposed to aggregate, characters at the s... more Most analyses of species selection require emergent, as opposed to aggregate, characters at the species level. This "emergent character" approach tends to focus on the search for adaptations at the species level. Such an approach seems to banish the most potent evolutionary property of populations-variability itself-from arguments about species selection (for variation is an aggregate character). We wish, instead, to extend the legitimate domain of species selection to aggregate characters. This extension of selection theory to the species level wil concentrate, instead, on the relation between fitness and the species character, whether aggregate or emergent. Examination of the role of genetic variability in the long-term evolution of clades illustrates the cogency of broadening the definition of species selection to include aggregate characters. We reinterpret, in this light, a classic case presented in support of species selection. As originally presented, the species selection explanation ofvolutid neogastropod evolution was vulnerable to a counterinterpretation at the organism level. Once this case is recast within a definition of species selection that reflects the essential structure and broad applicability of hierarchical selection models, the organism-level reinterpretation of variability loses its force. We conclude that species selection on variability is a major force of macroevolution.
Studies in History and Philosophy of Science Part A, 2020
Keywords in Evolutionary Biology, 1992
Is the female orgasm adaptive? This is the main question that Lloyd raises in her book and like a... more Is the female orgasm adaptive? This is the main question that Lloyd raises in her book and like all good questions, it raises a host more. What counts as an adaptation? How should we define orgasm in females (by which Lloyd explicitly means human wo-men)? How should we distinguish between evolutionary accounts of female orgasm and of the clitoris? Lloyd’s book is a fascinating philosophical and statistical analysis of the various methods and rationales with which biologists have argued for the adaptive value of female orgasm in the last forty years. The Case of the Female Orgasm also contributes to a variety of recent discussions in the history and philosophy of biology – from the separate evolutionary interests of males and females, to the value of anthropomorphism as an analytical tool in the study of human biology, and the rela-tionship of biologists ’ social values and their biological conclusions. As Lloyd explains at the outset, the main question she addresses in the book is n...
<jats:p>The biological theory of evolution advances the view that the variety and forms of ... more <jats:p>The biological theory of evolution advances the view that the variety and forms of life on earth are the result of descent with modification from the earliest forms of life. Evolutionary theory does not attempt to explain the origin of life itself, that is, how the earliest forms of life came to exist, nor does it apply to the history of changes of the non-biological parts of the universe, which are also often described as 'evolutionary'. The mechanisms of natural selection, mutation and speciation are used in evolutionary theory to explain the relations and characteristics of all life forms. Modern evolutionary theory explains a wide range of natural phenomena, including the deep resemblances among organisms, the diversity of life forms, organisms' possession of vestigial organs and the good fit or 'adaptedness' between organisms and their environment.</jats:p> <jats:p>Often summarized as 'survival of the fittest', the mechanism of natural selection actually includes several distinct processes. There must be variation in traits among the members of a population; these traits must be passed on from parents to offspring; and the different traits must confer differential advantage for reproducing successfully in that environment. Because evidence for each of these processes can be gathered independently of the evolutionary claim, natural selection scenarios are robustly testable. When a trait in a population has arisen because it was directly selected in this fashion, it is called an adaptation.</jats:p> <jats:p>Genetic mutation is the originating source of variation, and selection processes shape that variation into adaptive forms; random genetic drift and various levels and forms of selection dynamic developed by geneticists have been integrated into a general theory of evolutionary change that encompasses natural selection and genetic mutation as complementary processes. Detailed ecological studies are used to provide evidence for selection scenarios involving the evolution of species in the wild.</jats:p> <jats:p>Evolutionary theory is supported by an unusually wide range of scientific evidence, gaining its support from fields as diverse as geology, embryology, molecular genetics, palaeontology, climatology and functional morphology. Because of tensions between an evolutionary view of homo sapiens and some religious beliefs, evolutionary theory has remained controversial in the public sphere far longer than no less well-supported scientific theories from other sciences.</jats:p>
Frontiers in Neuroscience, Sep 1, 2022
Can machine learning crack the code in the nose? Over the past decade, studies tried to solve the... more Can machine learning crack the code in the nose? Over the past decade, studies tried to solve the relation between chemical structure and sensory quality with Big Data. These studies advanced computational models of the olfactory stimulus, utilizing artificial intelligence to mine for clear correlations between chemistry and psychophysics. Computational perspectives promised to solve the mystery of olfaction with more data and better data processing tools. None of them succeeded, however, and it matters as to why this is the case. This article argues that we should be deeply skeptical about the trend to black-box the sensory system's biology in our theories of perception. Instead, we need to ground both stimulus models and psychophysical data on real causal-mechanistic explanations of the olfactory system. The central question is: Would knowledge of biology lead to a better understanding of the stimulus in odor coding than the one utilized in current machine learning models? That is indeed the case. Recent studies about receptor behavior have revealed that the olfactory system operates by principles not captured in current stimulusresponse models. This may require a fundamental revision of computational approaches to olfaction, including its psychological effects. To analyze the different research programs in olfaction, we draw on Lloyd's "Logic of Research Questions," a philosophical framework which assists scientists in explicating the reasoning, conceptual commitments, and problems of a modeling approach in question.
Philosophy of Science
Modern science’s ability to produce, store, and analyze big datasets is changing the way that sci... more Modern science’s ability to produce, store, and analyze big datasets is changing the way that scientific research is practiced. Philosophers have only begun to comprehend the changed nature of scientific reasoning in this age of “big data.” We analyze data-focused practices in biology and climate modeling, identifying distinct species of data-centric science: phenomena-laden in biology and phenomena-agnostic in climate modeling, each better suited for its own domain of application, though each entail trade-offs. We argue that data-centric practices in science are not monolithic because the opportunities and challenges presented by big data vary across scientific domains.
In this brief chapter, Lloyd sets the stage for the following three papers, most centrally, Sante... more In this brief chapter, Lloyd sets the stage for the following three papers, most centrally, Santer et al. (2008a), which discusses whether the satellite data fit with climate models. Its target is a paper by Douglass et al. (Douglass DH, Christy JR, Pearson BD, Singer SF, A comparison of tropical temperature trends with model predictions. Int J Climatology 28:1693–1701, 2008), which claimed that satellite and weather balloon data showed that the climate models were wrong and could not be trusted. The Santer and Wigley “Fact Sheet” (Chap. 4) gives a nontechnical summary of what is wrong with the Douglass paper, while the full story is in Chap. 5, a reprint of the Santer et al. (2008a) paper. The context and import of this work is discussed in Lloyd (Chap. 6). In this introduction, Lloyd emphasizes the timeliness of this work, as climate deniers testify in Congress presently.
Biological Theory, 2017
Holobionts, consisting of a host and diverse microbial symbionts, function as distinct biological... more Holobionts, consisting of a host and diverse microbial symbionts, function as distinct biological entities anatomically, metabolically, immunologically, and developmentally. Symbionts can be transmitted from parent to offspring by a variety of vertical and horizontal methods. Holobionts can be considered levels of selection in evolution because they are welldefined interactors, replicators/reproducers, and manifestors of adaptation. An initial mathematical model is presented to help understand how holobionts evolve. The model offered combines the processes of horizontal symbiont transfer, within-host symbiont proliferation, vertical symbiont transmission, and holobiont selection. The model offers equations for the population dynamics and evolution of holobionts whose hologenomes differ in gene copy number, not in allelic or loci identity. The model may readily be extended to include variation among holobionts in the gene identities of both symbionts and host.
Epistemology & Philosophy of Science, 2019
Perspectives in Biology and Medicine, 2006
Pickering & Chatto, Dec 1, 2014
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Papers by Elisabeth Lloyd