The proximate/ultimate distinction in the multiple careers of Ernst Mayr

Ernst Mayr's distinction between “ultimate” and “proximate” causes is justly considered a major contribution to philosophy of biology. But how did Mayr come to this “philosophical” distinction, and what role did it play in his earlier “scientific” work? I address these issues by dividing Mayr's work into three careers or phases: 1) Mayr the naturalist/researcher, 2) Mayr the representative of and spokesman for evolutionary biology and systematics, and more recently 3) Mayr the historian and philosopher of biology. If we want to understand the role of the proximate/ultimate distinction in Mayr's more recent career as a philosopher and historian, then it helps to consider hisearlier use of the distinction, in the course of his research, and in his promotion of the professions of evolutionary biology and systematics. I believe that this approach would also shed light on some other important “philosophical” positions that Mayr has defended, including the distinction between “essentialism: and “population thinking.”     

Ernst Mayr: Biologist-historian

Ernst Mayr's historical writings began in 1935 with his essay Bernard Altum and the territory theory and have continued up through his monumentalGrowth of Biological Thought (1982) and hisOne Long Argument: Charles Darwin and the Genesis of Modern Evolutionary Thought (1991). Sweeping in their scope, forceful in their interpretation, enlisted on behalf of the clarification of modern concepts and of a broad view of biology, these writings provide both insights and challenges for the historian of biology. Mayr's general intellectual formation was guided by the GermanBildung ideal, with its emphasis on synthetic and comprehensive knowledge. His understanding of how to write history was inspired further by the example of the historian of ideas Arthur Lovejoy. Some strengths and limitations of this approach are explored here through attention to Mayr's treatment of the French biologist J.-B. Lamarck. It is contended that Mayr's contributions to the history of biology are not restricted to his own very substantial historical writings but also include his encouragement of other scholars, his development of an invaluable archive of scientific correspondence, and his insistence that historians who write about evolution and related subjects acquire an adequate understanding of the principles of Darwinian biology.This paper was originally delivered at the biennial meeting of the International Society for the History, Philosophy, and Social Studies of Biology, held in Brandeis in July 1993, in the special session organized by John Greene on Ernst Mayr's contributions to systematics, evolutionary theory, and the history and philosophy of biology. The paper is presented here with only slight modifications of the original, oral presentation. As indicated in the text, a full assessment of Mayr's historical work, including situating that work in the context of Mayr's other work and contemporary developments in the history of science, would require a much more extensive study than I have been able to undertake here.     

Plant response to climate change along the forest‐tundra ecotone in northeastern Siberia

Russia's boreal (taiga) biome will likely contract sharply and shift northward in response to 21st century climatic change, yet few studies have examined plant response to climatic variability along the northern margin. We quantified climate dynamics, trends in plant growth, and growth–climate relationships across the tundra shrublands and Cajander larch (Larix cajanderi Mayr.) woodlands of the Kolyma river basin (657 000 km²) in northeastern Siberia using satellite‐derived normalized difference vegetation indices (NDVI), tree ring‐width measurements, and climate data. Mean summer temperatures (T_s) increased 1.0 °C from 1938 to 2009, though there was no trend (P > 0.05) in growing year precipitation or climate moisture index (CMI_gy). Mean summer NDVI (NDVI_s) increased significantly from 1982 to 2010 across 20% of the watershed, primarily in cold, shrub‐dominated areas. NDVI_s positively correlated (P < 0.05) with T_s across 56% of the watershed (r = 0.52 ± 0.09, mean ± SD), principally in cold areas, and with CMI_gy across 9% of the watershed (r = 0.45 ± 0.06), largely in warm areas. Larch ring‐width measurements from nine sites revealed that year‐to‐year (i.e., high‐frequency) variation in growth positively correlated (P < 0.05) with June temperature (r = 0.40) and prior summer CMI (r = 0.40) from 1938 to 2007. An unexplained multi‐decadal (i.e., low‐frequency) decline in annual basal area increment (BAI) occurred following the mid‐20th century, but over the NDVI record there was no trend in mean BAI (P > 0.05), which significantly correlated with NDVI_s (r = 0.44, P < 0.05, 1982–2007). Both satellite and tree‐ring analyses indicated that plant growth was constrained by both low temperatures and limited moisture availability and, furthermore, that warming enhanced growth. Impacts of future climatic change on forests near treeline in Arctic Russia will likely be influenced by shifts in both temperature and moisture, which implies that projections of future forest distribution and productivity in this area should take into account the interactions of energy and moisture limitations.     

北京市华北落叶松优树群体遗传多样性分析

利用SSR分子标记对北京市华北落叶松人工林5个群体的220棵优树进行遗传多样性和群体结构分析。20对SSR引物共检测到81个等位基因,每个位点等位基因数2~8个不等,平均4.05个。群体观测和期望杂合度平均值分别为0.429和0.440,Shannon信息指数和多态性信息含量分别为0.756和0.380。5个群体中,百花山和云蒙山遗传多样性水平最高,雾灵山遗传多样性水平最低。AMOVA分析结果显示,2.65%的遗传变异来自于群体间,剩余97.35%的遗传变异来自于群体内。遗传分化系数仅为0.023,表明北京市华北落叶松优树群体遗传分化程度很低。基于Nei's遗传距离可以将5个群体划分为3个类群,四海镇和雾灵山归为第Ⅰ类,松山归为第Ⅱ类,百花山和云蒙山归为第Ⅲ类。STRUCTURE群体结构分析结果与上述聚类分析结果大体一致。以上研究为华北落叶松人工林遗传多样性评价和优良种质资源收集、保护和利用提供理论依据。     

150 Jahre “Biogenetisches Grundgesetz”

150 years “Biogenetic Law” The zoologist Ernst Haeckel is one of the most well‐known, but also one of the most controversial scientists of the late 19th and early 20th centuries. He was one of the earliest Darwinists and a forceful advocate of evolutionary theory. Together with “Darwin's Bulldog” Thomas Henry Huxley, Haeckel was a central figure in the early history and popularization of Darwinism. But his name is not only a symbol for the disputes about the theory of evolution and its popularization, but also for a campaign for monism, a world‐view or philosophy created by Haeckel himself. Together with Fritz Müller, Ernst Haeckel was one of the first to formulate a “Biogenetic Law”. He also created several concepts and terms still in use in biology today, such as “ontogeny”, “phylogeny”, “ecology”, “cholorogy” and “phylum” in his first, and maybe most important book “General Morphology of Organism”, which was published in 1866, 150 years ago.     

SOFAST-HMQC Experiments for Recording Two-dimensional Deteronuclear Correlation Spectra of Proteins within a Few Seconds

Fast multidimensional NMR with a time resolution of a few seconds provides a new tool for high throughput screening and site-resolved real-time studies of kinetic molecular processes by NMR. Recently we have demonstrated the feasibility to record protein ¹H–¹⁵N correlation spectra in a few seconds of acquisition time using a new SOFAST-HMQC experiment (Schanda and Brutscher (2005) J. Am. Chem. Soc. 127, 8014). Here, we investigate in detail the performance of SOFAST-HMQC to record ¹H–¹⁵N and ¹H−¹³C correlation spectra of proteins of different size and at different magnetic field strengths. Compared to standard ¹H–¹⁵N correlation experiments SOFAST-HMQC provides a significant gain in sensitivity, especially for fast repetition rates. Guidelines are provided on how to set up SOFAST-HMQC experiments for a given protein sample. In addition, an alternative pulse scheme, IPAP-SOFAST-HMQC is presented that allows application on NMR spectrometers equipped with cryogenic probes, and fast measurement of one-bond ¹H–¹³C and ¹H–¹⁵N scalar and residual dipolar coupling constants.     

The Ibis: Transformations in a Twentieth Century British Natural History Journal

The contents of the British Ornithologists' Union's journal, The Ibis, during the first half of the 20th century illustrates some of the transformations that have taken place in the naturalist tradition. Although later generations of ornithologists described these changes as logical and progressive, their historical narratives had more to do with legitimizing the infiltration of the priorities of evolutionary theory, ecology, and ethology than analyzing the legacy of the naturalist tradition on its own terms. Despite ornithologists' claim that the journal's increasing focus on "biology" represented a natural development after the preliminary phase of systematics and geographical ornithology, in fact a small group campaigned to bring the priorities of population ecology, behavior, and selection theory into the journal and British ornithology more generally. The problems involved in this transition highlight the importance of methodological and institutional context in determining and reinforcing appropriate research programs for ornithologists. Comparing the discipline-building rhetoric of moderns with the contents of the past illustrates how modern evaluations of 19th century research programs have been enmeshed in ornithologists' endeavors to forge new identities for traditional disciplines.     

The Discovery of Stereoselectivity at Biological Receptors: Arnaldo Piutti and the Taste of the Asparagine Enantiomers—History and Analysis on the 125th Anniversary

In 1886, Italian chemist Arnaldo Piutti isolated, for the first time, d ‐asparagine, the enantiomer of the known l ‐asparagine. He obtained 100 g of d ‐asparagine from 6500 kg of vetches. Using an ingenious synthetic scheme, Piutti established the chemical structure of asparagine and demonstrated that his isolation of d ‐asparagine from plants was not the result of the racemization of l ‐asparagine during the extraction procedure. He found a striking difference in the taste of asparagine: l ‐asparagine was without taste, while d ‐asparagine was intensely sweet. This was the first example of enantioselectivity in a receptor‐mediated biological activity. Receptors constitute one of the most important and most intensively studied phenomena in biology, and enantioselectivity in receptor‐mediated activity, including at the sweetness receptor, is today an important and commonly seen aspect of receptor function. Therefore, Piutti's discovery, although made ca. 15 years before the emergence of the receptor concept, was a milestone. The publication of Piutti's asparagine work prompted several eminent scientists, including Louis Pasteur and Arthur Cushny, a leading pharmacologist of the time, to remark on the importance of the discovery. Piutti also carried out investigations in many other fields, e.g., other organic compounds and reactions, pharmaceuticals, alimentary products, radioactivity, noble gases, and spectroscopy. Considerable progress has been made in recent decades concerning the biology and chemistry of sweet taste, but the details of the interactions of chiral molecules with the sweetness receptor remain poorly understood. Piutti and his discovery are largely forgotten today; they deserve the attention of the chirality and receptor “communities.” Chirality 24:959–976, 2012. © 2012 Wiley Periodicals, Inc.     

Evolutionary Morphology in Belgium

In historical literature, Edouard van Beneden (1846–1910) is mostly remembered for his cytological discoveries. Less well known, however, is that he also introduced evolutionary morphology – and indeed evolutionary theory as such – in the Belgian academic world. The introduction of this research programme cannot be understood without taking both the international and the national context into account. It was clearly the German example of the Jena University that inspired van Beneden in his research interests. The actual launch of evolutionary morphology at his University of Liège was, however, also connected with the dynamic of Belgian university reforms and the local rationale of creating a research “school.” Thanks to his networks, his mastering of the rhetoric of the “new” biology, his low ideological profile and his capitalising on the new academic élan in late-19th century Belgium, van Beneden managed to turn his programme into a local success from the 1870s onwards. Two decades later, however, the conceptual underpinnings of evolutionary morphology came under attack and the “Van Beneden School” lost much of its vitality. Despite this, van Beneden’s evolutionary morphology was prototypical for the research that was to come. He was one of the first scientific heavyweights in Belgium to turn the university laboratory into a centre of scientific practice and the hub of a research school.     

Speciation on islands: what are we learning?

Systematics and the Origin of Species from the Viewpoint of a Zoologist has remained an essential text on the bookshelves of evolutionary biologists since it was first published. Here, I expand upon several topics touched upon by Ernst Mayr to look at how our thinking has evolved, and is evolving, with particular reference to molecular phylogenetic studies on islands. At the time of publication, apart from the fossil record, inferences of temporal trends or patterns could only be speculative, deduced from the distributions of species and the patterns that these present. Much like the subject material itself, evolutionary biology evolves as a discipline, with an increasing availability of tools and resources. The development of molecular phylogenetics and molecular markers has given biologists a new window on the past and, as such, the ideas and explanations of Mayr have become more accessible to testing. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 47–52.