Elisabeth Vrba

Elisabeth Vrba ( born May 27, 1942 in Hamburg ) is a paleontologist and professor of geology and geophysics at Yale University in New Haven ( Connecticut ). She became internationally known in 1980 by a trade publication in the South African Journal of Science. In this publication, she reached into a run since the early 1970s, debate the theory of evolution between representatives of gradualism and punctuated equilibrium in favor of the Punctuated Equilibrium and formulated at the same time for the first time today well-known hypothesis that climate change before 2.5 to 2 million years ago in Africa to an accelerated " species change" led. Your supported mainly by studies of fossil antelopes hypothesis radiated rapidly to the study of evolutionary history of man, because in this era - the transition from Pliocene to Pleistocene - in Africa emerged the Homo genus from the genus Australopithecus.

Together with Stephen Jay Gould developed Elisabeth Vrba 1982 in demarcation to adaptation, the concept of exaptation.

Career

Elisabeth Vrba was born in Hamburg. She was two years old when her mother emigrated with her to Namibia after her father - a professor of law - had fallen at sea; in Namibia was already living her mother's sister. There, her mother 's second marriage was a sheep farmer who felt qualified training of girls as useless. She could still enforce their desire to visit a high school and later in South Africa, University of Cape Town. There she earned undergraduate degrees in 1964 and 1965 of Mathematical Statistics of Zoology. Then Vrba moved for one year to the Zoological Institute of the University of Witwatersrand in Johannesburg, and from 1967 to 1968, she taught high school students of St. Alban 's College in Pretoria. In 1967 she married her husband George.

From 1969 to 1972 worked Elisabeth Vrba - initially free of charge - as experts for the Transvaal Museum in Pretoria. There, his longtime manager, Charles Kimberlin Brain, a large collection of remains of fossil antelopes had collected that had to be cleaned and sorted by attaching rocks. In the course of their building upon doctorate, she learned that antelope - unlike most other vertebrates - have a striking feature, from which their membership can be derived to a certain kind: While males and females of many species to each other, for example, based on their behavior, their plumage, or their coat color seen ( of features that are not in the fossil record ), to recognize the members of an antelope - type on the shape of their horns. This insight was the basis of her 1980 formulated considerations on the mechanisms of evolution. Your thus created international fame led to her in South Africa, the Star Women of the Year Award 1982 was awarded (and in the working woman of the year).

From 1973 to 1986 Vrba headed the Department of Paleontology and Paleoanthropology of the Transvaal Museum; In 1975, she graduated from the University of Cape Town doctoral degrees in field zoology / paleontology. From 1976 to 1986 she headed the excavation projects at the archaeological site of Kromdraai australopithecine - and in Broederstroom in South Africa's North West Province. From 1977 to 1986 she was also deputy director of the museum.

In 1986, Elisabeth Vrba of a professorship in geology and geophysics from Yale University and has taught since 1987 at the same time in field biology. Also since 1987, she has worked as a curator of vertebrate paleontology and osteology at the university's Peabody Museum of Natural History.

Research Topics

First, she published (1968 ) on fish skull. After Elisabeth Vrba in 1969 started with the assignment of antelope fossils to particular types, she noticed that the time usual definition of evolutionary success was not applicable to the antelopes: As a successful those Chrono species which were - as the wildebeest - in particularly large number of successor species had split. Vrba stated in contrast, that many wildebeest species were extinct again One million years after their first appearance, for example, while fossil relatives of Impalas, there were four million years and emerged in this period, only a few follow- types from them. Together with a colleague could Vrba also demonstrate that even among the living in the Kruger National Park recent antelopes the impala evolutionary supposedly less successful much more often occurred as the wildebeest of the various species. At the same time she noticed that wildebeest are specialized in the grasses in dry, open savanna, while impala colonize both savannas and wooded areas. From this they deduced that food specialists are more sensitive to climatic changes in their environment as generalists, and therefore the one hand, it quicker to react in terms of a species change, on the other hand also exposed to higher risk of extinction. Your 1980 published in the South African Journal of Science data and considerations wore the hitherto internationally acclaimed researcher not invitations to lectures at numerous prestigious universities, including Harvard, Oxford and Cambridge.

Since Elisabeth Vrba now also launched the paleoanthropological collection of the Transvaal Museum and excavations at Kromdraai ( where Robert Broom had discovered in 1938 the first fossil of Paranthropus robustus ), fell to her parallels the evolution of antelope and Hominini on: At the same time, as before around 5 million and then again before 2.5 to 2 million years ago changed the species composition of antelope quickly, there were significant changes in the species composition in the great apes. First, the lines of development of the chimpanzee and the Hominini parted; 2.5 million years ago it came to the transition from the " gracile " australopithecines to the " robust" australopithecines to the genus Paranthropus and parallel to the transition from the " gracile " australopithecines to the genus Homo. Vrba led these changes in terms of adaptive radiation to climate change in Africa back; this led them off from the analysis of fossil teeth antelope, the nature (with the soft leaves as food) was close and then in dry grasslands (less soft food ) before a stay in moist forest areas. Paleoclimate analysis later confirmed that the closing of the land bridge between North and South America have led to a redirection of ocean currents and to around 2.5 million years ago to a cooling in Africa (see Känozoisches Ice Age ). At the time, Africa was drier and the rain forest areas declined.

Your interpretation of the causes of the change of species has been in the English language known as the "turn -over pulse" hypothesis (eg: hypothesis about the causes that give the impetus for change ). In 1992, she linked this hypothesis with other ecological factors of evolution to a Habitat theory of macroevolution. This completes the competition paradigm ( " Survival of the Fittest " ), alleging individual species are gradually replaced by other types down to extinction. According to the Habitats theory, it is mainly dramatic environmental changes that provide the impetus both to adapt quickly - and thereby to the rapid emergence of new species - as well as a rapid disappearance of existing species.

Publications by Vrba (selection)

• Role of Environmental stimuli in Hominid Origins. In: W. Henke, H. Rothe, I. Tattersall (ed.): Handbook of Palaeoanthropology, Vol 3: Phylogeny of Hominines. Springer - Verlag, New York, 2006, pp. 1-41
• ( with D. DEGUSTA ): Do species populations really start small? New perspectives from the Late Neogene fossil record of African mammals. Phil Trans R. Soc. Lond. B, Volume 359, 2004, pp. 285-293
• Climate, heterochrony, and human evolution. Journal of Anthropological Research, Volume 52, 1996, pp. 1-28
• Elisabeth S. Vrba, GH Denton, TC Partridge, LH Burckle (eds.): Paleoclimate and evolution with emphasis on Human Origins. Yale University Press, New Haven, Connecticut, 1995
• Mammals as a key to evolutionary theory. Plenary Keynote Address, 70th Congress of the American Society of Mammalogists, June 1990, Frostburg, Maryland. Journal of Mammalogy, Volume 73 (1 ), 1992, pp. 1-28
• Environment and evolution: Alternative Causes of the temporal distribution of evolutionary events. South African Journal of Science, Vol 81 (5 ), 1985, pp. 229-236