Speaker Series

Fall 2018

  • Paul Smaldino
  • 09-17-2018
  • Paul Smaldino
  • UC Merced, Cognitive and Information Systems
  • The Natural Selection of Bad Science
  • Science is an enterprise that uses rationality and investigation to build increasingly accurate models of the natural world. Practitioners of science have a vast toolkit of investigatory and analytic methods at their disposal—a toolkit that changes over time. Are their discernible patterns in the adoption of methods over time? Empirical science can in many cases be thought of as a problem of signal detection for facts, in which the challenge is to accurately detect a true signal among potential noise. If scientists are incentivized only or primarily by the quest for truth, then any methodological improvement to signal strength should be adopted, provided any associated costs are manageable. Instead, scientists are often rewarded for the acquisition of tokens, such as publication count or journal impact factor. If methodological strategies that maximize token counts are misaligned with those that increase signal strength, the probability that scientific results reflect reality will fall. I will present empirical evidence and the results of formal modeling to support this conclusion and suggest that many current incentive structures in professional science organization are detrimental to the ultimate aims of scientific research. I will conclude with some thoughts on how organizations can act to improve the quality of science research.

  • Carlos Botero
  • 10-01-2018
  • Carlos Botero
  • Washington University St. Louis, Biology
  • Ecological and evolutionary modeling shed light into the evolution and spread of human agriculture
  • The human species has existed for at least 100K years, mostly as a hunter-gatherer. However, around 12 KYA, a few societies in different parts of the world suddenly developed agriculture forever altering our ecology and way of life. Why did this transformative innovation originate in those specific places and around roughly the same time? How did it manage to spread so quickly throughout the world to become our predominant form of subsistence? For decades, these fundamental questions have eluded definitive answers partly because of the highly fragmentary nature of the archeological record. While careful scholarship and attention to detail have provided various plausible alternative hypotheses, quantitative analyses that investigate the relative weight of evidence supporting these ideas tend to be lacking. My talk will cover the various ways in which my collaborators and I have taken advantage of recent advances in cultural phylogenetics, computational biology, and evolution to begin filling these important gaps. Specifically, I will discuss how we (1) hind casted the population dynamics of hunter-gatherers to evaluate whether agriculture most likely originated in times of need or in times of surplus; (2) used climate niche modeling to evaluate whether the 11 to 19 areas of origin were somehow different than other places concurrently inhabited by humans; (3) investigated the ways in which switches in subsistence strategy altered the tempo and mode of evolution of the environmental tolerances of our ancestors; and (4) used machine leaning to evaluate whether the rapid spread of agriculture was most likely enabled by war, cultural diffusion (i.e., sharing), or both.

  • Virpi Lummaa
  • 10-15-2018
  • Virpi Lummaa
  • University of Turku, Finland, Biology
  • Why and how we grow old: cooperation and conflict in human families
  • With mid-life menopause, women show a radical de-coupling of senescence in reproductive and somatic systems, leading to up to half of total lifespan spent post-reproductive. By contrast, men maintain reproductive ability until much later ages. Although men thus sire offspring at older ages than women, in nearly all contemporary human populations women outlive men by on average of five years. While proximate causes for such fertility and lifespan differences between the sexes are well-known, our understanding of the underlying evolutionary forces for why and how we grow old is much more limited. My research focuses on ageing, lifespan and natural selection in contemporary human societies, using historical church records in an innovative way to look at evolutionary, ecological and demographic factors influencing birth and death rates in both men and women during the past 300 years. In this talk I address different evolutionary hypothesis for the benefits of menopause and post-reproductive longevity in women; assess whether selection on overall lifespan differs between the sexes; and reveal both cooperation and conflict between family members over the lifecourse of individuals. Understanding sex differences in rates of senescence in reproduction and survival, both key life-history traits, provides insights into how differing selection pressures can mould rates of senescence and ultimate longevity in our species. I hope to illustrate that although evolutionary studies on contemporary human populations suffer from many limitations, some of the data available on humans offer interesting research opportunities also for evolutionary biologists with potential implications for studies on demography, public health or anthropology.

  • Johannes Schul
  • 11-05-2018
  • Johannes Schul
  • University of Missouri, Biological Sciences
  • Insect Acoustic Communication as model for trait evolution in rapidly changing environments
  • Michael Roberts
  • 12-03-2018
  • Michael Roberts
  • University of Missouri, Biological Sciences
  • The evolution of the human placenta: not quite up there with the sheep or the horse
  • A still apt definition of a placenta is that it is an organ resulting from the apposition or fusion of the fetal membranes to the uterine mucosa, thereby allowing viviparity and exchange of solutes, gases and other molecules, e.g. hormones, between the maternal system and the developing offspring. By this definition, placentas have evolved within every vertebrate class other than birds. They have also emerged on multiple occasions, often within quite narrow taxonomic groups and over short periods of evolutionary time. As the placenta and the maternal system have evolved to associate more intimately, as in mammals, such that the conceptus comes to rely extensively on maternal support, the relationship leads to increased genetic conflict that drives adaptive changes on both sides. The story of vertebrate placentation, therefore, is one of convergent evolution at both the macro- and molecular levels. In this talk, I shall first describe the emergence of placental-like structures in non-mammalian vertebrates. I shall then attempt to explain the diversification of placentation encountered in mammals where, among extant species, a bewildering range of structures is encountered. I’ll emphasize the success of non-invasive placental types as encountered in horses, pigs, and domestic ruminant species in providing young born in a relatively mature and independent state. I close the review by discussing mechanisms that might have favored diversity and hence evolution of the morphology and physiology of the placentas of eutherian mammals.