Adolf Seilacher
Encyclopedia
Adolf "Dolf" Seilacher is a German palaeontologist who has made major contributions to evolutionary and ecological palaeobiology in a career stretching over 60 years. He won the Crafoord Prize
in 1992, the Paleontological Society Medal in 1994 and the Palaeontological Association
's Lapworth Medal
in 2006. He is best known for his contributions to the study of trace fossils; constructional morphology and structuralism
; biostratinomy
(including "aktuopaläontologie") exceptional preservation and the Ediacaran biota.
Gaining his doctorate in 1951 on trace fossils, Seilacher moved to the University of Frankfurt (1957) and then the University of Baghdad before taking up a chair in palaeontology in Göttingen. He returned to Tübingen in 1964 as the successor to Schindewolf. Since 1987 he has held an Adjunct Professorship at Yale University in New Haven (Connecticut), and splits his time between Yale and Tübingen.
: distinctive assemblages of trace fossils controlled largely by depth. This characterisation was later expanded to include the influences of substrate, oxygen, salinity and so on. In addition, he analysed many trace fossils in terms of the behaviour they represent, leading to such work as early computer simulation of trace fossil morphology (with David Raup, in 1969). Much of this work is summarized together with new material in Trace Fossil Analysis (2007).
In 1970 he announced his programme of "Konstructions-Morphologie" where he stressed the importance of three factors in determining the form of organisms: ecological/adaptive aspects; historical/phylogenetic aspects; and architectural/constructional aspects. The latter two factors are important sources of biological constraints
; both acknowledging that both past history and constructional principles place limits on what may be achieved in at least the short term of evolution. Such a view was influential on later workers such as Stephen Jay Gould
and Richard Lewontin
, such as their famous paper on "spandrels
" that criticized panadaptionist accounts of evolution and form.
Seilacher's interest in pattern formation led him to espouse self-organisation models for the origin of certain types of form, the most famous of which are "pneu" structures. These are fluid-filled structures under tension whose form is broadly determined by the need to distribute the tension across the surface. Seilacher may thus be squarely considered to be a structuralist
.
Seilacher has published important papers on fossil Lagerstätten, including one of 1985 that proposed a widely-accepted scheme for their classification; indeed, much of his work has been concerned with preservation and taphonomy
in general.
His most controversial contributions have come in his work on the Ediacaran
assemblages, which he and Friedrich Pflüger (1994) suggested, based on their constructional morphology, to be pneu structures completely unrelated to modern metazoans. While this view has been steadily opposed by many workers, it has gained some ground in recent years as the affinities of many of these organisms has remained resistant to analysis. More recently, Seilacher has considered many of these taxa to be giant xenophyophores, i.e. large rhizopodal protists. He appeared in the film Volcanoes of the Deep Sea
, going on a dive on the DSV Alvin
to investigate the apparent trace fossil Paleodictyon
, which is a pet project.
Crafoord Prize
The Crafoord Prize is an annual science prize established in 1980 by Holger Crafoord, a Swedish industrialist, and his wife Anna-Greta Crafoord...
in 1992, the Paleontological Society Medal in 1994 and the Palaeontological Association
Palaeontological Association
The Palaeontological Association is a charitable organisation based in the UK founded in 1957 for the promotion of the study of palaeontology.-Functions:...
's Lapworth Medal
Lapworth Medal
The Lapworth Medal is the highest award of the Palaeontological Association, given to those who have made a significant contribution to the science by means of a substantial body of research.Recent winners are:*2010 - Dr Robin Cocks...
in 2006. He is best known for his contributions to the study of trace fossils; constructional morphology and structuralism
Structuralism (biology)
Biological or process structuralism is a school of biological thought that deals with the law-like behaviour of the structure of organisms and how it can change....
; biostratinomy
Biostratinomy
Biostratinomy is the study of the processes that take place after an organism dies but before its final burial. It is considered to be a subsection of the science of taphonomy, along with necrology and diagenesis...
(including "aktuopaläontologie") exceptional preservation and the Ediacaran biota.
Career
Seilacher started his career with his doctoral work under Otto Heinrich Schindewolf, professor of palaeontology at the University of Tübingen. He was also influenced by local palaeontologist Otto Linck. He served in World War II and resumed his studies at Tübingen, corresponding among others with the French ichnologist, Jacques Lessertisseur.Gaining his doctorate in 1951 on trace fossils, Seilacher moved to the University of Frankfurt (1957) and then the University of Baghdad before taking up a chair in palaeontology in Göttingen. He returned to Tübingen in 1964 as the successor to Schindewolf. Since 1987 he has held an Adjunct Professorship at Yale University in New Haven (Connecticut), and splits his time between Yale and Tübingen.
Significant work
Seilacher's publications are numerous (well over 200) and cover a range of topics. His studies on trace fossils are perhaps his best-known contributions, especially his 1967 work on the bathymetry of trace fossils. Here he established the concept of ichnofaciesIchnofacies
An ichnofacies is an assemblage of trace fossils that provide an indication of the conditions that their formative organisms inhabited.-The concept:...
: distinctive assemblages of trace fossils controlled largely by depth. This characterisation was later expanded to include the influences of substrate, oxygen, salinity and so on. In addition, he analysed many trace fossils in terms of the behaviour they represent, leading to such work as early computer simulation of trace fossil morphology (with David Raup, in 1969). Much of this work is summarized together with new material in Trace Fossil Analysis (2007).
In 1970 he announced his programme of "Konstructions-Morphologie" where he stressed the importance of three factors in determining the form of organisms: ecological/adaptive aspects; historical/phylogenetic aspects; and architectural/constructional aspects. The latter two factors are important sources of biological constraints
Biological Constraints
Biological constraints are factors which make populations resistant to evolutionary change. Constraint has played an important role in the development of such ideas as homology and body plans.- Types of constraint:...
; both acknowledging that both past history and constructional principles place limits on what may be achieved in at least the short term of evolution. Such a view was influential on later workers such as Stephen Jay Gould
Stephen Jay Gould
Stephen Jay Gould was an American paleontologist, evolutionary biologist, and historian of science. He was also one of the most influential and widely read writers of popular science of his generation....
and Richard Lewontin
Richard Lewontin
Richard Charles "Dick" Lewontin is an American evolutionary biologist, geneticist and social commentator. A leader in developing the mathematical basis of population genetics and evolutionary theory, he pioneered the notion of using techniques from molecular biology such as gel electrophoresis to...
, such as their famous paper on "spandrels
Spandrel (biology)
In evolutionary biology, a Spandrel is a phenotypic characteristic that is a byproduct of the evolution of some other characteristic, rather than a direct product of adaptive selection.-Origin of Term:...
" that criticized panadaptionist accounts of evolution and form.
Seilacher's interest in pattern formation led him to espouse self-organisation models for the origin of certain types of form, the most famous of which are "pneu" structures. These are fluid-filled structures under tension whose form is broadly determined by the need to distribute the tension across the surface. Seilacher may thus be squarely considered to be a structuralist
Structuralism (biology)
Biological or process structuralism is a school of biological thought that deals with the law-like behaviour of the structure of organisms and how it can change....
.
Seilacher has published important papers on fossil Lagerstätten, including one of 1985 that proposed a widely-accepted scheme for their classification; indeed, much of his work has been concerned with preservation and taphonomy
Taphonomy
Taphonomy is the study of decaying organisms over time and how they become fossilized . The term taphonomy was introduced to paleontology in 1940 by Russian scientist Ivan Efremov to describe the study of the transition of remains, parts, or products of organisms, from the biosphere, to the...
in general.
His most controversial contributions have come in his work on the Ediacaran
Ediacaran
The Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon...
assemblages, which he and Friedrich Pflüger (1994) suggested, based on their constructional morphology, to be pneu structures completely unrelated to modern metazoans. While this view has been steadily opposed by many workers, it has gained some ground in recent years as the affinities of many of these organisms has remained resistant to analysis. More recently, Seilacher has considered many of these taxa to be giant xenophyophores, i.e. large rhizopodal protists. He appeared in the film Volcanoes of the Deep Sea
Volcanoes of the Deep Sea
Volcanoes of the Deep Sea is a 2003 documentary film directed by Stephen Low in the IMAX format about undersea volcanoes.-Production:Richard Lutz served as Principal Investigator and Lutz and Peter Rona served as Science Directors of the film, which was funded by the National Science Foundation and...
, going on a dive on the DSV Alvin
DSV Alvin
Alvin is a manned deep-ocean research submersible owned by the United States Navy and operated by the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts. The vehicle was built by General Mills' Electronics Group in the same factory used to manufacture breakfast cereal-producing...
to investigate the apparent trace fossil Paleodictyon
Paleodictyon
Paleodictyon is a pattern, usually interpreted to be a burrow, which appears in the geologic record beginning in the Cambrian and in modern ocean environments. Both irregular and regular nets are known throughout the stratigraphic range of Paleodictyon, but it is the striking regular honeycomb...
, which is a pet project.
External links
- Form and Function: A Tribute to Adolf Seilacher - Peabody Museum of Natural History, Yale University