Behavior, Evolution, and Culture Speaker Series

Mondays 12:00-1:30, Haines Hall 352, UCLA

Free lunch will be provided for attending UCLA faculty and graduate students, and for undergraduates who are enrolled in the BEC seminar. For budgetary reasons, non-UCLA attendees who wish to partake of the lunch will be asked to make a $7 per person donation.

Spring Quarter 2006

3 April: Peter Whybrow Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry & Biobehavioral Science, UCLA David Geffen School of Medicine http://www.peterwhybrow.com

American Mania: When More Is Not Enough

Dr. Whybrow poses the question, “Are we Americans becoming the first addicts of the technological age?” Despite an astonishing appetite for life, more and more Americans are feeling overworked and dissatisfied in the world’s most affluent nation, epidemic rates of stress, anxiety, depression, obesity, and time urgency are now grudgingly accepted as part of everyday existence—they signal the American Dream gone awry. Drawing upon economics, history, evolutionary psychology, and scientific case studies, Dr. Whybrow ground the extraordinary achievements and excessive consumption of the American nation in an understanding of the biology of human craving and the reward system of the brain—offering a comprehensive physical explanation for the addictive mania of consumerism. Whybrow shows how human biology is ill equipped to cope with the demands of the 24/7, global, information-saturated, rapid-fire culture we not only have created but also have come to crave.Dr. Whybrow concludes with a discussion of how one may step back from this treadmill to live a healthful life. But he also offers a cautionary tale: As a society if we do not learn to curtail our cravings, we may be entering a self-destructive phase. Fundamental to change will be an objective evaluation of the laissez-faire market ideology and a reinvigoration of our role as citizens in this driven consumer culture.

American Mania Quiz

10 April: Jeffrey Davis California State University Long Beach Department of Sociology

Fisher’s Sociological Imagination

Fisher is widely known for his extraordinary contributions to population genetics and evolutionary biology. His sociological insights have received far less attention, even though five of the twelve chapters of The Genetical Theory of Natural Selection are devoted to developing a theory of the evolutionary consequences of human social organization. For my presentation, I will review Fisher's sociology and the parameters of his model of social organization. I also offer some extensions to Fisher's model. In conclusion, I contend that Fisher's insights provide the basis of a rich theoretical research program in evolutionary sociology.

17 April: Chris Guzelian Searle Scholar, Northwestern University School of Law

Evolution, Selfish Lies, and Free Speech

Evidence increasingly suggests that selection between competing ideas to become a prevailing social belief may be strongly influenced by evolutionarily descended limitations on human sensory and mental capabilities. Scholars posit that these limitations permit many "selfish" ideas to gain social traction and spread epidemically, driving out and shutting out truth from collective understanding in the selection process. An evolutionary perspective, combined with settled principles of free speech law, indicates that the explicit combating of various selfish false ideas through technological, educational, legal, financial, or other means may be necessary to avoid self-sustaining mass delusions in a globalizing world.

24 April: Joseph Campos UC Berkeley Department of Psychology; President, International Society on Infant Studies

Co-sponsored by the UCLA Interdisciplinary Relationship Science Program

On the Epigenesis of Fear in the Human Infant

There is a fascinating paradox about fear of heights in humans and some animal species. Such fear has enormous biological adaptive value, represents a true life-span emotional reaction, and constitutes one of the strongest and most reliably-elicited fears in the human. As such, one would expect fear of heights to be innate, or under strong maturational control. Indeed, until recently, it was so considered. However, there is now no doubt that fear of heights develops as the result of experience, more specifically experiences linked to the onset of self-produced locomotion. It is not a maturational or innate event.

What creates fear of heights and how does locomotor experience play a role in its ontogeny? We can rule out three likely candidates as playing a causal role. Depth perception is well established before such fear develops; falling experiences are relatively rare; and maternal emotional signaling has little if any impact at the age of onset of locomotion. What, then, may be the process(es) by which such biologically-adaptive wariness comes about?

In this talk, evidence is presented for the role of a discrepancy between sensory systems in the ontogeny of these fears. The discrepancy we propose to be playing a causal role is related to the discrepancy that in adults makes heights “dizzying.” More specifically, one experiences height vertigo when information reaches the brain that the head and body is moving (even minutely so), but visual information discrepantly fails to confirm such self-movement. It turns out that infants have good vestibular and kinesthetic information about self-movement from early in life, but lack responsiveness to flow in the visual periphery until after the acquisition of locomotor experience. So, only after “visual proprioception” becomes functional is the infant capable of experiencing the discrepancy that produces height vertigo.

The talk will:

(a) Visually illustrate what visual proprioception is (it is not a phenomenon well-known to behavioral scientists),

(b) Provide evidence for the role of locomotor experience on visual proprioception, and

(c) Present results of two studies showing correlations between responsiveness to optic flow and the probability of showing wariness of heights in infants at two different ages.

Click here to download the paper (Word document)

1 May: Nancy Burley UC Irvine Department of Ecology & Evolutionary Biology

Sexual Imprinting: New Approaches to an Old Problem

Sexual imprinting, a process by which early contact with parents shapes the mate preferences of developing young, has been widely documented among birds and has been reported for other vertebrates, especially mammals (including humans). Historically, studies of imprinting have emphasized causal and ontogenetic perspectives, with function and evolutionary consequences receiving less attention. Recent quantitative models have investigated a possible role for sexual imprinting in vertebrate speciation processes, but little empirical support for this possibility has been provided. Moreover, recent studies suggest that sensory drive processes exert strong, unlearned influences on mate preferences which might override tendencies to imprint on novel traits that emerge in incipiently diverging populations. Here I report results of several experiments designed to evaluate the tendency of both sexes of zebra finches to imprint on novel traits of parents with otherwise normal phenotypes. The novel (experimental) traits are crests of various colors and patterns. Previous research (Burley & Symanski 1998) indicates that female zebra finches reared with wild-type (uncrested)parents have sensory biases favoring white-crested males; normally reared males lack this bias and favor uncrested females. By rearing young with crested parents, I investigated how sensory drive and imprinting processes interact. Results suggest that imprinting responses of both sexes may vary considerably with the perceived information content of experimentally manipulated traits, and that some evolutionarily novel traits may promote reproductive isolation in diverging populations.

Click here to download the paper (PDF)

8 May: Michael Shermer Skeptic Magazine

Evonomics: Natural Selection, the Invisible Hand, and the New Science of Evolutionary Economics

There are a number of parallels between evolution and economics that we shall explore on two tiers—historical and theoretical: the parallels between natural selection and the invisible hand; the nature of evolution and the characteristics of a free market economy; the reluctance to accept the theory of evolution and free market economics; evolution and economics as emergent properties; how evolution shaped economic behavior; and contingency in evolution and path dependency in economies. In short, natural selection and the invisible hand are analogous descriptors for analogous phenomena.

15 May: Bruce Winterhalder UC Davis Department of Anthropology

Seven Reasons to Remain a Forager

Archaeological research shows that many human populations continued to hunt-and-gather for thousands of years after beginning the use of plant domesticates. This kind of mixed economy is rare in the ethnographic literature on foragers and horticulturalists; its persistence for millennia in the early stages of agricultural origins is inexplicable under much current theory. In this paper I describe models and concepts from evolutionary anthropology which may help us to explain this novel,persistent, prehistoric mode of production. The more important ones include (a) the population ecology of the domesticates themselves, (b) environmental fluctuation, (c) temporal discounting of subsistence options, (d) maintenance of technological knowledge in low-density populations, and (e) institutional mechanisms of risk-manage under changing economic regimes. Collectively these ideas are meant to demonstrate, contra Sahlins and substantivism, the utility of a selective set of micro-economic concepts in the study of pre-market economies.

22 May: Robert Hoffmann Department of Economics, Nottingham University Business School, The University of Nottingham

Religion, Religiosity and Cooperation: An Experimental Study from Malaysia

Huntington's notion of a clash of cultures has attracted a great deal of attention in recent years. In particular, religious differences as well as religious fundamentalism have been identified as crucial dimension of present culture clashes. We conducted a study to explore to what extent different religions and religiosity affect the economic interactions between individuals as a test of this notion. The study is based on religious attitude surveys and incentivised economic experiments with repeated prisoner's dilemma play among Malaysian subjects. The multi-ethnic nature of Malaysia is ideally suited to match subjects for game play from the world's major religions (Islam, Catholicism, Protestantism, Hinduism and Buddhism) while holding other socio-economic factors constant.

29 May: Memorial Day Holiday

5 June: Dacher Keltner UC Berkeley Department of Psychology

Evolution's Soul: What Laughter, Smiling, Lip Puckers, and Goosebumps Tell us About the Evolution of Human Goodness

In this talk I will present recent work on the pro-social emotions. I will present studies of smiling, the relations between oxytocin and the nonverbal displays of love and desire, and recent evidence exploring the role of vagus nerve activity in compassion and pro-social dispositions. I will use these data to offer the beginnings of a theory of the emotion-related origins of pro-sociality, drawing upon Darwin's own speculations and those of recent philosophers and behavioral scientists.

Winter Quarter 2006

9 January: Dan Posner UCLA Department of Political Science http://www.polisci.ucla.edu/faculty/posner

Ethnic Diversity and Public Goods Provision in Kampala, Uganda: An Experimental Approach

16 January: Martin Luther King, Jr. Holiday

23 January: Steven Gaulin UCSB Department of Anthropology

A Real-World Foraging Task Yields a Female Advantage and Significant Content Effects.

Though Silverman and Eals division-of-foraging-labor hypothesis cannot explain the cross-species distribution of sex differences in spatial ability, it does make a novel prediction: women will more accurately remember the location of stationary resources. Unfortunately, Silverman and Eals’ own tests of this hypothesis have yielded weak and inconsistent support, possibly because the tasks used to assess the hypothesized female advantage lack ecological validity. I will present results of a controlled field study carried out at a large farmers market. Women performed significantly better than men at remembering the location of food items they had tasted, but not at remembering the location of non-food landmarks. In addition, accuracy was significantly correlated with the caloric content of food items, suggesting specialization of this particular cognitive system.

30 January: Rafael Nuñez UCSD Department of Cognitive Science

Embodied Cognition, Objectivity, and Truth: Lessons from Mathematics
and Spatial Construals of Time in Aymara

How can we "objectively" share abstract entities with others, in a stable and consistent way? How can we evaluate "Truth" when purely imaginary entities are concerned? Mathematics provides a very intriguing case for studying these questions. Indeed, mathematics, on the one hand deals with purely imaginary entities (e.g., a Euclidean point has only location, but no extension! ... And there is no such "real" thing in the entire universe!), and on the other hand, it provides extremely stable patterns of true-valued inferences (i.e., theorems) that once proved, stayed proved for ever (e.g., the Pythagorean Theorem). In this talk I will analyze these issues by looking at (1) my own work on the Cognitive Science of Mathematics (with George Lakoff) taking examples from set and hyperset theory, and (2) my field work in the Andes' highlands studying--with convergent linguistic-gestural-ethnographic methods--a very peculiar form of spatial construal of time in the Aymara culture. I'll address the question of the role of axiom systems in generating and sustaining truth, and will show that the nature of truth and objectivity in abstract conceptual systems lie on the intricacies of the underlying bodily-grounded human cognitive mechanisms (e.g., conceptual metaphors, metonymies, analogies, blends) that make them possible.

6 February: Gail Heyman UCSD Department of Psychology http://www.psy.ucsd.edu/~gheyman

Children’s Reasoning about People as Source of Information

The human capacity to acquire knowledge from others, rather than only relying upon what can be observed or experienced directly, opens vast opportunities for learning. As a result of this capacity, humans are highly adaptable across many contexts. However, the use of such
information can also pose difficulties. For example, sources may provide incorrect or misleading information, either intentionally or unintentionally. In this talk, I will focus on children's evaluation of others as sources of information within one particular context: when
people talk about themselves. The findings I will present, which include data collected in the U.S. and in China, address how children's reasoning is affected by the content of the message, and by the social context in which the communication occurs.

13 February: John Patton California State University Fullerton Department of Anthropology

Coalitional Psychology and the Conundrum of Altruism: a case from the Ecuadorian Amazon

The search for solutions to the conundrum of altruism is a central focus of evolutionary approaches to the study of human behavior. The focus of this talk is to present data on cooperation collected among horticultural foragers in the Ecuadorian Amazon to argue that a better understanding of the conundrum of altruism, and its constraints, can be gained by examining human cooperation as an aspect of an evolved coalitional psychology. Coalitional psychology is that aspect of human nature designed to construct mental representations of coalitional structures, to triangulate oneself and others within coalitional structures, to reason about and pursue behavioral strategies within
coalitional contexts, and to evoke emotional states that led to actions that result from or create coalitional consequences. Apart from
explicit or implicit attempts to detect group boundaries (ethnic, spatial, or political) and the collection of basic demographic data,
evolutionary ethnographers do not routinely collect data on coalitional structures. Without such data it is difficult to assess the influences
of coalitional thinking on cooperation which predicts that people will weigh the costs and benefits of cooperating differently depending on
their position within their coalitional. Even in egalitarian societies some people are more equal than others. In this talk I will integrate
data on coalitional structure derived from network analysis techniques, with data on behavior within three separate domains of cooperation
(status allocation, meat sharing, and experimental economic games) to illustrate influences of an evolved coalitional psychology on patterns of human cooperation.

20 February: President's Day Holiday

27 February: Teresa Seeman UCLA David Geffen School of Medicine Division of Geriatrics

Exploring a Bio-Psychosocial Model of Cumulative Risk – Biological Pathways Linking Life Experience and Health Outcome in Aging

Dr. Seeman will discuss evidence linking socio-economic, social and psychological resources to trajectories of health and aging and the multiple biological pathways through which these factors appear to impact on health outcomes over the life course. Possible sex and/or ethnic differences in these patterns of association will also be discussed.

6 March: Leeat Yariv Caltech Division of Humanities and Social Sciences, UCLA Department of Economics

Conformity In The Lab

In this talk, I will briefly survey the existing literature on social learning and conformity (both theoretical and experimental) and then present evidence from an array of new experiments disentangling conformity, an intrinsic taste to follow others, from informational herding in a sequential choice setting. In these experiments, we use a design reminiscent of the standard social learning setup in which subjects choose the type of information they observe before making a decision. Namely, subjects choose between observing a private and informative signal or observing a social signal manifested in the history of play of predecessors who have not chosen a private signal. Even though the latter type is essentially a word of mouth signal, entailing no statistical information, a significant fraction of subjects choose it persistently. Allowing for payoff externalities by paying subjects according to a collective action chosen by a majority vote amplifies the results. So does an increase in the stakes. Our design allows us to rule out alternative explanations the literature proposes such as confusion and inequality aversion.

13 March: Terrence Deacon UC Berkeley Department of Anthropology

Devo-Devo: How Relaxed Selection Can Contribute To The Evolution And Self-Organization Of
Complexity

Although biologists have long recognized examples of regressive processes in evolution as well as a role for regressive processes in the development of brains, research interest tends to focus on presumably constructive and progressive processes under the influence of natural selection. Particularly in the case of human brains and their evolution, it is generally assumed that the neurological differences underlying the complexity of human language abilities must have arisen due to progressive improvements of function via selection favoring these traits. In this talk I will explore an alternative possibility: that devolutionary loss-of-function due to reduced selection,
including degradation of developmental-genetic specificity, may contribute to the evolution of novel complex neural functions, such as language. The general logic of this argument originates from a critique of a commonly cited evolutionary mechanism: the Baldwin Effect. Although this theoretical “effect” is often invoked as an evolutionary mechanism leading from functional plasticity to increased specificity of genetic control, biological examples and simulation studies will be presented that show that the opposite effect is more likely, and also that there are other surprising correlates of this process. An animal example—song production in a domesticated species of finch—illustrates this effect and its paradoxical consequence. In this breed, increasingly complex song structure, expanded involvement of forebrain mechanisms, greater flexibility of behavior, and a larger contribution from social learning evolved without positive selection for these traits. Instead, these birds were bred for feather coloration. Absence of selection on song appears to have led to evolutionary degradation of song control specificity and with it unmasking of otherwise hidden synergies among diverse brain systems able to play some role in song structure. These results suggest some informative parallels with features of human language functions, and the possibility that regressive evolutionary processes might play an important role in the evolution of biological complexity more generally.

Fall Quarter 2005

3 October: Joseph Manson UCLA Department of Anthropology

Father-Daughter Inbreeding Avoidance Reduces Male Reproductive Skew

in a Wild Primate Population

Inbreeding reduces fitness in various taxa, and several behavioral and physiological mechanisms have evolved that inhibit fertile matings between close kin. Most commonly, members of one or both sexes disperse before breeding. In primates, males usually disperse and females often benefit from lifelong relationships with maternal kin within the group. Females thus risk breeding with their father if the tenure length of the dominant male, who usually sires most group offspring, exceeds the time it takes daughters to mature. Attempts to determine whether such co-resident father-daughter pairs systematically avoid inbreeding have produced equivocal results, and no published studies have addressed this question by genetically ascertaining paternity in a wild population. We determined paternity for 117 wild white-faced capuchins (Cebus capucinus) born into our study population. As expected, alpha males dominated reproduction. However, while siring the great majority (79%) of the offspring born to unrelated females, alphas sired only 6% (1 of 17) of the offspring conceived by their daughters during their tenures, providing evidence for effective inbreeding avoidance without female dispersal.

10 October: Antoine Bechara USC Department of Psychology

Decision-Making and Impulse Control After Frontal Lobe Injuries

For a long time, the prefrontal cortex has been considered a “non-functional” brain area, and understanding its function has lagged behind nearly all other areas. This is no longer true since appreciation of the vital role that this brain region plays in adaptive behaviors, and especially decision-making, is now evident more than ever. I will highlight the recent progress that has been made in this area of research. Decision-making is a term often referred to in the psychological literature as one of the “executive functions”, which play a role in managing (like an executive) other cognitive functions, such as memory, attention, and language. Considerable research efforts have been directed towards differentiating various processes of executive functions, but much of this effort in the past has focused on the dorsolateral prefrontal cortex (DLPC) sector. I will focus on decision-making and its link to the ventromedial prefrontal cortex (VMPC), and highlights the role of evolution in shaping the function of this area of the brain.

17 October: Susan Perry UCLA Department of Anthropology, Cultural Phylogeny Group, Max Planck Institute for Evolutionary Biology http://www.eva.mpg.de/phylogen

Social learning in wild capuchin monkeys

Recently, discoveries of site-specific behavioral patterns such as the use of hammers and anvils or stick tools in extractive foraging have been documented in wild ape populations. Such discoveries have given rise to much speculation regarding the evolution of cultural capacities in humans, and claims have been made that chimpanzees have a greater capacity for “culture” than any other nonhuman animal. However, theoretical models used to predict the circumstances under which social learning is expected to become important would not predict unusually high reliance on social learning to be unique to apes. Capuchin monkeys, for example, by virtue of their gregarious, tolerant nature, omnivory, extreme dependence on alliance partners, and extractive foraging niche, would be predicted to be highly reliant on social learning.

In this talk, I present the findings of a cross-site investigation (4 study sites, 13 social groups, 10 researchers, 19,000 hrs of data) documenting behavioral variation in social conventions and foraging techniques in white-faced capuchin monkeys. Whereas the ape “culture” researchers stopped at cross-site comparisons and declared the observed variation to be cultural by process of elimination, I continued to investigate the source of the variation by conducting cross-sectional and developmental studies in my data base from Lomas Barbudal (5 social groups, roughly 30,000 hrs of data dating from 1990). In this talk I present data on social conventions and also data on the acquisition of foraging techniques in young capuchins. Social influence is most important between the ages of 2-4 years, and by age 5, capuchins have conformed to the technique they observed most. This conformity takes place over a very slow time scale, contrary to theoretical expectations about the speed of social learning.

24 October: Francisco J. Ayala UCI Departments of Ecology & Evolutionary Biology and Philosophy

http://www.faculty.uci.edu/profile.cfm?faculty_id=2134

Darwin’s Greatest Discovery: Natural Selection versus Intelligent Design

Darwin is deservedly given credit for the theory of biological evolution. He accumulated evidence demonstrating that organisms evolve and diversify through time. Most important, however, is that he discovered natural selection, the process that accounts for the adaptive organization of organisms and their features; that is, their “design.” But the design of organisms is not intelligent, as it would be expected from an engineer, but imperfect and worse: the defects, dysfunctions, oddities, waste—and even cruelty and sadism if judged by human values—that pervade the living world are incompatible with their being the outcome of an intelligent designer, unless this designer would also be intentionally deceitful and malevolent.

31 October: Paul Zak Claremont Graduate University Neuroendocrine Foundations of Trust Department of Economics

http://www.pauljzak.com

Oxytocin Increases Trust in Humans

The traditional view in economics is that individuals respond to incentives, but absent strong incentives to the contrary selfishness prevails. Moreover, this “greed is good” approach is deemed “rational” behavior. Nevertheless, in daily interactions and in numerous laboratory studies, a high degree of cooperative behavior prevails—even among strangers. A possible explanation for the substantial amount of “irrational” behavior observed in markets (and elsewhere) is that humans are a highly social species and to an extent value what other humans think of them. This behavior can be termed trustworthiness—cooperating when someone places trust in us. A number of recent experiments from my lab have demonstrated that the neuroactive hormone oxytocin facilitates trust between strangers, and appears to induce trustworthiness. In rodents, oxytocin has been associated with maternal bonding, pro-social behaviors, and in some species long-term pair bonds, but prior to the work reviewed here, the behavioral effects of oxytocin in humans had not been studied. This presentation discusses the neurobiology of positive social behaviors and how these are facilitated by oxytocin. My experiments show that positive social signals cause oxytocin to be released by the brain, producing an unconscious attachment to a stranger.

7 November: Margo Wilson & Martin Daly McMaster University Department of Psychology

Carpe diem: adaptation and devaluing the future

The future is almost always worth less to organisms than the present, and evolved psychologies and physiologies 'discount' it accordingly. However, exactly how they do so, how they should do so, and whether real discount functions match theoretical expectations, are unresolved and/or controversial in various details, which will be the focus of discussion.

SPECIAL LATE-AFTERNOON DISTINGUISHED SPEAKER LECTURE -- OPEN TO THE PUBLIC, BRING A FRIEND!!

The UCLA Center for Behavior, Evolution, and Culture is proud to announce the first in an occasional series of public lectures spotlighting the work of the most distinguished scholars in evolutionary behavioral science. In addition to their BEC talk, the eminent (and dynamic!) duo of Martin Daly and Margo Wilson will speak on Monday, November 7th from 4:00 to 5:30 p.m. in 362 Royce Hall. Their focus:

Risky business: future discounting, inequality, and homicide

Homicide occurs primarily in competitive contexts, and can be considered an extreme manifestation of willingness to take risks and disregard future consequences in the pursuit of current goals. This argument suggests that factors that affect risk-taking and the perceived value of the future relative to the present will affect homicide rates. What such factors may be, and how they help explain the remarkable variability of homicide rates, will be examined in this talk.

14 November: Jeffrey Brantingham UCLA Department of Anthropology
http://paleo.sscnet.ucla.edu

Gone in 6 Seconds: the Foraging Behavior of Los Angeles Car Thieves

How specialized is your average Los Angeles "auto boost"? This talk draws on both new and classic foraging models to examine the search strategies deployed by Los Angeles car thieves and evaluates the decision making process underlying how they select individual cars to steal. It seems plausible that many of the foraging behaviors deployed by car thieves are linked to psychological and behavioral capacities that evolved among our hunter-gatherer ancestors. It is less likely that there is specialized (or broken) cognitive module linked to "deviant behavior". A dash of both trial-and-error and social learning mixed with generalized psychological and behavioral capacities is sufficient to generate very effective car thieves.

21 November: Shinobu Kitayama University of Michigan Department of Psychology

Voluntary Settlement and the Spirit of Independence

There is a general consensus that the history of voluntary settlement in the western frontier constitutes a major element of American individualism. Yet, if voluntary settlement is a causal factor that promoted tacit beliefs and practices of independent agency, there should be similar beliefs and practices among a group of people even in the midst of an entirely different cultural ethos of interdependence as long as the group had undergone voluntary settlement in the recent past. We thus examined residents of Japan’s northern island (Hokkaido). Hokkaido was extensively settled by ethnic Japanese from the 1870’s for several decades. Many of the current residents of Hokkaido are the descendents of the original settlers from this period. As predicted, Japanese socialized and/or immersed in Hokkaido were nearly as likely as European Americans in North America to commit a dispositional bias in causal attribution, to associate happiness with personal achievement, and to show a personal dissonance effect wherein self-justification is motivated by a threat to personal self-images. In contrast, these marker effects of independent agency were largely absent for non-Hokkaido residents in Japan. Implications for theories of cultural change are discussed.

28 November: Gregory F. Grether UCLA Department of Ecology and Evolutionary Biology

http://www.eeb.ucla.edu/Faculty/Grether/research.htm

Environmental Change, Phenotypic Plasticity and Genetic Compensation

Normal development depends on specific environmental inputs. Consequently, when a species encounters novel environmental conditions, some traits may develop abnormally. Changes in the environment can occur, for example, because of climate change or habitat degradation. Like genetic mutations, most environmental perturbations of development are detrimental, and thus natural selection would usually be expected to favor genetic changes that gradually restore the ancestral form of the trait in the new environment. I recently coined the term "genetic compensation" to describe this form of adaptive evolution. When genetic compensation occurs along a spatial environmental gradient, it partially or completely masks the effects of the gradient on trait development. This means that populations of a species that look the same in the wild may develop quite differently if placed in a common environment. In addition, genetic compensation may lead to a cryptic form of reproductive isolation between populations, explain some puzzling cases in which heritable traits exposed to strong directional selection fail to show the expected evolutionary response, and complicate efforts to monitor populations for signs of environmental deterioration. In this talk, I will explain how genetic compensation differs from related phenomena, such as genetic assimilation and canalization, and review putative examples to illustrate the above points.

5 December: Craig McKenzie UC San Diego Department of Psychology

http://www-psy.ucsd.edu/~mckenzie/

Framing Effects and Rationality

Framing effects are said to occur when "equivalent" redescriptions of objects or outcomes lead to different preferences or judgments. For example, a medical treatment is seen more favorably when described as resulting in "90% survival" rather than "10% mortality." Such effects are widely considered to be classic violations of rationality. However, if framing effects are to be considered irrational, it is not sufficient that the frames in question be logically equivalent. Instead, they must be information equivalent, which means that no choice-relevant inferences can be drawn from the speaker's choice of frame. However, logically equivalent frames used by researchers are often information non-equivalent. For example, we have shown that a speaker's choice of attribute frame "leaks" information about relative abundance, and that listeners "absorb" the information. Information leakage provides a natural (and rational) explanation of attribute framing effects. Extensions of the information leakage approach to framing effects in risky choice, inference tasks, consumer behavior, and policy defaults will also be discussed.

LINKS TO PREVIOUS YEARS’ BEC SPEAKER SERIES:

2004 - 2005 Speaker Series

2003 - 2004 Speaker Series

BEC Archives

The Behavior, Evolution and Culture Speaker Series is generously supported by:

UCLA Division of Social Sciences

UCLA Division of Humanities

UCLA Department of Anthropology

UCLA Department of Speech and Communication Studies

The Center for Behavior, Evolution, and Culture (BEC) unites scholars exploring the connections among evolution, culture, the mind, and society. BEC provides a framework to facilitate research and training on the interaction among natural selection, cultural transmission, social relations, and psychology. To learn more, visit the BEC homepage at http://www.bec.ucla.edu/

Everyone is welcome to attend, and to volunteer to present research.

To be added to the BEC list-serv, send a message to listserv@weber2.sscnet.ucla.edu
with the message (not subject) subscribe BEC your personal name (not user name).
To be taken off the BEC list-serv, send a message to listserv@weber2.sscnet.ucla.edu
with the message (not subject) signoff BEC

BEC holds quarterly conferences with UCSB's sister program in Evolution, Mind, and Behavior.
Links to previous conferences can be found in the archive.

For a variety of web-resources exploring the interactions between mind and culture,
see the International Culture and Cognition Program.

Some papers to be discussed may be in PDF format, which can be read only if you have previously downloaded the free Adobe Acrobat Reader .

This page is maintained by Daniel Fessler. Email: dfessler "at" anthro.ucla.edu (insert the @ symbol yourself)

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