Leonardo and the Whale

Around 1480, when he was 28 years old, Leonardo da Vinci recorded what may have been a seminal event in his life. In writing of his travels to view nature he recounted an experience in a cave in the Tuscan countryside: Having wandered for some distance among overhanging rocks, I can to the entrance of a great cavern... [and after some hesitation I entered] drawn by a desire to see whether there might be any marvelous thing within... [excerpt

Maria Sibylla Merian\u27s Frogs

Maria Sibylla Merian (German, 1647-1717) is best known for her magnificent 1705 publication, Metamorphosis insectorum surinamensium, although she published earlier works on insect metamorphosis. Merian wrote the text and painted all of the illustrations for her books, and for the early volumes she produced most of the engravings. Contemporary scholarship has focused primarily on Merian\u27s detailed images of lepidopteran and host plant life cycles, but Merian\u27s Surinam album also portrays anuram metamorphosis, including the first European depiction of Pipa pipa

Loathsome Beasts: Images of Reptiles and Amphibians in Art and Science

The mythology and symbolism historically associated with reptiles and amphibians is unequaled by that of any other taxonomic group of animals. Even today, these creatures serve as icons - often indicating magic or evil - in a variety of media. Reptiles and amphibians also differ from other vertebrates (i.e. fish, mammals and birds) in that most have never been valued in Europe as food or for sport. Aside from some limited medicinal uses and the medical concerns related to venomous species, there was little utilitarian value in studying the natural history of reptiles and amphibians. Because of this history and other characteristics of these animals, the images of reptiles and amphibians played a unique role in the study of natural history from the Medieval through the Early Modern periods. The images I will discuss come from books that have been analyzed by other scholars, but in most cases there has been little or no scrutiny of the portrayal of the herpetofauna. Because much of my research as a biologist has focused on reptiles and amphibians, I will consider their differences from mammals and birds. In doing so, I will address image content from a somewhat different point of view than that of an art or science historian. My contention is that understanding the evolving portrayal of these “loathsome beasts” is particularly useful in tracing the development of the study of natural history. I also will address how changes in these images over time reflect a transformation in how nature was viewed and valued in western European culture. [excerpt

The History and Influence of Maria Sibylla Merian\u27s Bird-Eating Tarantula: Circulating Images and the Production of Natural Knowledge

Chapter Summary: A 2009 exhibition at the Fitzwilliam Museum on the confluence of science and the visual arts included a plate from a nineteenth-century encyclopedia owned by Charles Darwin showing a tarantula poised over a dead bird (figure 3.1).1 The genesis of this startling scene was a work by Maria Sibylla Merian (German, 1647–1717), and the history of this image says much about how knowledge of the New World was obtained, and how it was transmitted to the studies and private libraries of Europe, and from there into popular works like Darwin’s encyclopedia. It is unlikely that Merian ever imagined the future longevity and influence of her images and text, but her visual records, like those of other naturalist/artists, were employed by Buffon, Linnaeus, and others in their efforts to understand and order plants and animals from around the world. [excerpt] Book Summary: This volume offers fresh perspectives on key elements of science in societies throughout Spanish America, Europe, West Africa, India, and Asia as they overlapped increasingly during the Age of Revolutions—an era of rapidly expanding scientific investigation—as well as the role of scientific change and development in tightening global and imperial connections

Review of Eye of Newt and Toe of Frog, Adder’s Fork and Lizards’ Leg, the Lore and Mythology of Amphibians and Reptiles

A review of Marty Crump\u27s book on the folklore surrounding reptiles and amphibians. Crump\u27s book is a collection of tales and myths both ancient and contemporary, and a fascinating analysis of how humans perceive and sometimes revere snakes, frogs and other loathsome creatures

Scaling limits of weakly asymmetric interfaces

We consider three models of evolving interfaces intimately related to the weakly asymmetric simple exclusion process with $N$ particles on a finite lattice of $2N$ sites. Our Model 1 defines an evolving bridge on $[0,1]$, our Model 1-w an evolving excursion on $[0,1]$ while our Model 2 consists of an evolving pair of non-crossing bridges on $[0,1]$. Based on the observation that the invariant measures of the dynamics depend on the area under (or between) the interface(s), we characterise the scaling limits of the invariant measures when the asymmetry of the exclusion process scales like $N^{-\frac{3}{2}}$. Then, we show that the scaling limits of the dynamics themselves are expressed in terms of variants of the stochastic heat equation. In particular, in Model 1-w we obtain the well-studied reflected stochastic heat equation introduced by Nualart and Pardoux

Diffusion approximation of a multilocus model with assortative mating

To understand the effect of assortative mating on the genetic evolution of a population, we consider a finite population in which each individual has a type, determined by a sequence of n diallelic loci. We assume that the population evolves according to a Moran model with weak assortative mating, strong recombination and low mutation rates. With an appropriate rescaling of time, we obtain that the evolution of the genotypic frequencies in a large population can be approximated by the evolution of the product of the allelic frequencies at each locus, and the vector of the allelic frequencies is approximately governed by a diffusion. We present some features of the limiting diffusions (in particular their boundary behaviour and conditions under which the allelic frequencies at different loci evolve independently). If mutation rates are strictly positive then the limiting diffusion is reversible and, under some assumptions, the critical points of the stationary density can be characterised.Comment: 56 pages, 8 figures ; corrected typo

Maria Sibylla Merian (1647-1717): Pioneering Naturalist, Artist, and Inspiration for Catesby

Book Summary: While accessible to the interested general reader, it is a technical standard that is usable academically. Containing significant new information, this work is the most comprehensive and accurate book written about Catesby and is the legacy of the Catesby Commemorative Trust’s Mark Catesby Tercentennial symposium held in 2012. Chapter Summary: Merian\u27s books on European and Surinamese insects and plants provided new models for representing nature that were echoed in the work of artists and naturalists working in the eighteenth century and beyond. This chapter discusses how Mark Catesby, the subject of the book, was particularly influenced by Merian

Rescaling limits of the spatial Lambda-Fleming-Viot process with selection

We consider the spatial Lambda-Fleming-Viot process model for frequencies of genetic types in a population living in R^d, with two types of individuals (0 and 1) and natural selection favouring individuals of type 1. We first prove that the model is well-defined and provide a measure-valued dual process encoding the locations of the `potential ancestors' of a sample taken from such a population. We then consider two cases, one in which the dynamics of the process are driven by events of bounded radii and one incorporating large-scale events whose radii have a polynomial tail distribution. In both cases, we consider a sequence of spatial Lambda-Fleming-Viot processes indexed by n, and we assume that the fraction of individuals replaced during a reproduction event and the relative frequency of events during which natural selection acts tend to 0 as n tends to infinity. We choose the decay of these parameters in such a way that when reproduction is only local, the measure-valued process describing the local frequencies of the less favoured type converges in distribution to a (measure-valued) solution to the stochastic Fisher-KPP equation in one dimension, and to a (measure-valued) solution to the deterministic Fisher-KPP equation in more than one dimension. When large-scale extinction-recolonisation events occur, the sequence of processes converges instead to the solution to the analogous equation in which the Laplacian is replaced by a fractional Laplacian. We also consider the process of `potential ancestors' of a sample of individuals taken from these populations, which we see as a system of branching and coalescing symmetric jump processes. We show their convergence in distribution towards a system of Brownian or stable motions which branch at some finite rate. In one dimension, in the limit, pairs of particles also coalesce at a rate proportional to their collision local time.Comment: 97 page

Genealogical constructions of population models

Representations of population models in terms of countable systems of particles are constructed, in which each particle has a `type', typically recording both spatial position and genetic type, and a level. For finite intensity models, the levels are distributed on $[0,\lambda ]$, whereas in the infinite intensity limit $\lambda\rightarrow\infty$, at each time $t$, the joint distribution of types and levels is conditionally Poisson, with mean measure $\Xi (t)\times \ell$ where $\ell$ denotes Lebesgue measure and $\Xi (t)$ is a measure-valued population process. The time-evolution of the levels captures the genealogies of the particles in the population. Key forces of ecology and genetics can be captured within this common framework. Models covered incorporate both individual and event based births and deaths, one-for-one replacement, immigration, independent `thinning' and independent or exchangeable spatial motion and mutation of individuals. Since birth and death probabilities can depend on type, they also include natural selection. The primary goal of the paper is to present particle-with-level or lookdown constructions for each of these elements of a population model. Then the elements can be combined to specify the desired model. In particular, a non-trivial extension of the spatial $\Lambda$-Fleming-Viot process is constructed