On August 12th, 2005 the world of paleobotany lost one of its greatest research minds of the last half of the 20th Century. Jack A. Wolfe was not only an extraordinary systematist with an encyclopedic knowledge of angiosperm leaf architecture, but he went where few paleobotanists dare go; he ventured into the realms of multivariate statistics in pursuit of quantifying the relationship between foliar physiognomy and climate. His ability to go well beyond botanical observation and description into using fossil leaves as tools for understanding environmental change through time has defined an area in modern palaeobotany that has found application is fields as diverse as meteorology and crustal dynamics.
Born and raised in Portland Oregon, Jack Albert Wolfe attended Franklin High School where, with the encouragement of his biology teacher Anne Bohlen, he first developed his interest in palaeobotany. Anne was the adviser to the school Science Club and in 1952 she arranged a club visit to the fossil museum that Lon Hancock, a retired postal worker had made in his home. Lon was an amateur who had helped furnish localities and material to both Ralph Chaney and Chester Arnold, and was a founder of the Oregon Museum of Science & Industry (OMSI). Lon, under the auspices of OMSI, started a summer field camp in the John Day Basin of central Oregon. Looking for a research project to write up for the Westinghouse Science Talent Search, Jack attended the second year of the OMSI field camp and became fascinated with two classic palaeobotanical sites near the camp: the Clarno nut bed and the Bridge Creek leaf flora. Jack’s project must have been impressive because, as one of 40 finalists, he won a trip to Washington and one of the contest judges, the Harvard astronomer Harlow Shapley, encouraged Jack to apply to both Harvard and Princeton. Unfortunately the application and scholarship deadlines had both passed, but still Shapley made encouraging noises. In the end Jack finished in the top 10 and went to Harvard in 1953 on a full scholarship.
At Harvard, Jack did his undergraduate research under the direction of botanist Elso S. Barghoorn and where for almost every day for 3 years Jack had lunch and coffee with the group that included I.W. Bailey, Don Whitehead, and Margaret Davis, among others, and visitors such as Sherwin Carlquist. With the stimulation of such company and building on his avid collecting in the Pacific Northwest, Jack had his first paleobotanical publication only a year after being admitted to Harvard. It was on the Collawash flora of the upper Clackamas River Basin and appeared in the Newsletter of the Geological Society of Oregon. During the summers at Harvard Jack gained further field experience joining, on separate occasions, Roland Brown, Dallas Peck and J.F. Smith who were all with the US Geological Survey (USGS). In this way Jack gained a breadth of experience that went way beyond palaeobotany and saw him mapping Cenozoic volcanic rocks of the Cascades and Palaeozoic sedimentary rocks in Nevada.
In 1957 Jack began his graduate studies in paleobotany at Berkeley under Wayne L. Fry, A.S. Foster and Herbert L. Mason and in 1959 was awarded an M.A. in Palaeontology after writing a thesis on the Tertiary Juglandaceae of Western North America. At Berkeley, Jack was particularly influenced by J. Wyatt Durham, the mollusk/echinoderm worker. Jack realized that mollusk workers had rigorous criteria for identifying their material and this prompted him to try the same approach with angiosperm leaves. With the encouragement of Adriance Foster (an I.W. Bailey connection) Jack starting leaf clearing in 1958 and by 1969 this had evolved into a project to survey modern dicots using cleared leaves. Eventually the USGS cleared leaf collection (now housed at the Smithsonian Institution in Washington) represented around 15,000 species and Jack had become, in his own words, “the largest herbarium beetle known to exist”. His rigorous approach was one of the major foundation stones of modern leaf architectural analysis in fossil angiosperm leaf identification and comparative studies.
In 1960 (when still only 23) Jack completed his PhD dissertation on the early Miocene floras of northwest Oregon. This rapid academic advancement was achieved alongside reporting on referred fossils for the US Geological Survey under the supervision of Preston E. Cloud. Jack’s industry was rewarded with a post that led him to being Research Geologist with the US Geological Survey, Menlo Park California. Jack remained with the USGS throughout much of his career, mostly at Menlo Park, but with spells in Washington DC (1961-65) and Denver (1982-1992).
In 1969 Jack produced his first major work on fossil floras: it was a synthesis of his findings on the Late Tertiary floras of the Pacific Northwest, which he published in Madrono in time for it to be handed out to attendees of the International Botanical Congress in Seattle that year.
In the 1960’s Jack also began work on the Tertiary floras of Alaska. In publications with David Hopkins, Clyde Wahrhaftig and Estella Leopold, he presented a first cut on dating the younger floras of the Kenai Lowland as Late Tertiary. Before this biostratigraphic work, many prominent geologists considered the rocks of the Kenai Group as being of Paleogene age. Jack continued and produced in 1977 a monumental and thoughtful work on the Paleogene floras of Alaska and Wrangellia , which still stands as an exceptional monograph. One of the reasons it was so notable is that he established for the first time that truly subtropical floras existed as far north as 60° N. Lat.
Jack’s primary role at the USGS was to use plant megafossils for biostratigraphic and paleoenvironmental determinations, but through his collaboration with Elso Barghoorn he also factored the pollen record into his deliberations. He not only undertook fieldwork himself, primarily in the western US including Alaska, but also identified material brought in to him by scores of geologists working throughout the United States. After a long and highly productive career at the USGS Jack retired to and adjunct position with the University of Arizona in 1992, where he remained an active researcher and, as at Berkeley, actively supervised research students, most of whom have continued working in paleobotany and have co-authored papers with him.
One of his important monographs, published in 1979, was the climatic analysis of the forest types in eastern China described by Wang Chi Wu in the 1960’s. He adapted the quantitative comparison of mean annual temperature with seasonal range of temperatures in different forest types. It resulted in his development of nomograms that sketch out the climatic parameters of the forest types, not only for eastern China, but for eastern and western North America and Australia. His nomogram models are widely used by botanists today.
While Jack’s reputation as a systematist and biostratigrapher will be remembered for a long time, probably his most innovative work was in quantifying the relationship between leaf form and environmental conditions, primarily climate. Following on from the pioneering work of I.W. Bailey and E. W. Sinnott, Jack recognised that leaf form is controlled by an interplay between the genotype honed through evolution and a spectrum of environmental factors. As early as the late 1970’s he realised that the best way to decode the complex form/climate relationship was through multivariate analysis. He set about building and testing a unique database of foliar physiognomic characters derived from leaves of woody dicots growing in vegetation for which the climate (weather-station data) is quantified through long term observation. His rigorous collecting methodology incorporated the full observable morphological range rendering the approach remarkably robust in the face of taphonomic filters. The technique, which he named CLAMP (Climate Leaf Multivariate Programme ), has found application not only in the North America and Japan where the calibration datasets have their origin, but in Russia, Europe, South America and New Zealand. Most spectacularly the technique yields data on enthalpy, a property of a parcel of air that can be used to determine paleoelevation. In recent years this approach has been applied to the uplift of Tibet and the Andes. However for some years Jack had an interest in the uplift history of the western US and it was here that he tested the technique, something he was still working on when he died falling from an outcrop in the eastern Sierras.
Jack always had an eye for detail and abhorred what he regarded as sloppy work. This, coupled with a tendency to be fairly brusque, a trait that he sometimes resorted to in order to disguise his innate shyness, led to feuds with some colleagues and he was a critical reviewer. Nevertheless those who became his close friends discovered a man of great intellect, loyalty, warmth and generosity.
Jack Wolfe is already sorely missed by his colleagues and students. We have lost a singular leader and scholar of paleobotany. We are privileged to honour his life by following where he led in the study of the major evolutionary and stratigraphic problems, and the relationship between plants and climate: areas of endeavour where Jack blazed an important trail.
Bob Spicer and Estella Leopold.