AASP Primary Records Program

Interview conducted November 26, 2002, in Chia, Colombia, by Hernando Dueñas.
revised 01/24/02

Good morning.

I was born in Schiedam, Netherlands in 1924, and my parents were Cornelis Van der Hammen and Josina Van der Spuy. My brother and sister are Elisabeth Cornelia and Leendert. Later I married in Columbia and I worked there in the fifties. I married Ana Malo Rojas, and three children were born also in Colombia: Tomas, Maria Clara and Cornelio Bernardo.

Well, it is near to Bogotá, and it is in the countryside. We have lived a long time in the Netherlands as a matter of fact, but when I was retired officially from the University of Amsterdam, we came back to live in Colombia. I have a long history in Colombia. Of course my wife is from here and my children were born here. And, we have made a lot of investigations in the area, in South America in general but especially in Colombia. And so, I feel at home here, and we decided to pass the last part of our life here.

That is difficult to say. I think I was a boy of about 10 years or so. I first was very much interested in astronomy, and at that time I had books that I didn't understand quite well, but I read them with much interest. And then when I was twelve years old, I became interested in geology after visiting the Geological Museum. From that time on I started to collect stones, fossils and anything; and my interest grew over in general to natural sciences, especially to biology, and we made collections of insects, plants, etc. In the same hand, we studied birds. I had a very wide interests.

My brother was interested also in biology. And we did several things together. The first contact, you see, was in the visit to the Museum. And, from there on it developed, and I think it is something that goes on all throughout your life. Once you are interested in nature, in general then it just takes a very important place in your life. It has to do with life in general. And you find life and the history of life in geology and in biology. So, that is my interest and I went on with that same interest the rest of my life.

My brother is a biologist who has also retired. As a matter of fact, he worked on spiders and mites, and he was quite an important scientist in this field. My sister studied art history and that is a different subject but I am interested in art as well.

I knew about palynology in the early years before the war. And though I knew that it existed, I did not start studying it until after the war. During the war we had some literature, but we could not start to study, because the universities were closed. In 1945, I started studying geology with a strong accent on the biological part. Shortly afterwards, Professor F. Florschutz joined the University of Leiden. He had been working in the first part of the century on palynology and paleobotany in The Netherlands, and after the war he became a teacher. So, I wrote a thesis with him and learned palynology from Professor Florschutz. That was the first phase of my knowledge and it was just what I was looking for, because I was interested in both geology and biology. I found in palynology really everything I was interested in - vegetation and vegetation history during the Pleistocene and the Quaternary, but also in the pre-Quaternary.

Well, I remember, of course, my classmates, and some of them went on in paleopalynology. But, one fellow student, who came in a few years after me was Waldo Zagwijn, who really was an important palynologist especially in the Pliocene and the Quaternary of The Netherlands and Europe. Jan Muller also learned pollen analysis with Florschutz.

Well, of course my Professor F. Florschutz was the first one who interested me in the question of palynology, but another person who was very important to me was Johannes Iversen. He was one of these palynologist who had a profound sense of ecology. He was also an ecologist. He was in the Geological Survey of Denmark, and I had the opportunity to pass several weeks in his laboratory. So I learned a lot from him, especially his ideas about vegetation and the interpretation of palynological data on an ecological basis. He was very important for me. But there were other people of course who I met. In paleopalynology there was Potonie. Potonie, Thompson and Kremp, all of these people, they were there in the beginning of paleopalynology, or pre-Quaternary palynology.

I attended some informal meetings before that time, but my first palynological meeting, I think, was the First International Botanical Congress, after the war, in 1950, in Stockholm. There was a special palynological meeting, where almost everybody in palynology was there. There was Potonie, Erdtman, Firbas, Iversen, Faegri, Thompson. Gordon and Mitchell. Jan Muller, was there already. We were young, of course. It was an excellent opportunity to give my first paper at the International Botanical Congress.

My first special palynological study was of a lake the Netherlands, where for the first time we discovered the whole sequence of late glacial climatic and vegetational changes. It was in Twente, it was called the Hijkermeer. It was my first more important paper in palynology. At the same time we studied the early Pleistocene and Pliocene vegetation and macro remains and pollen in the southern part of The Netherlands in the Tegelen Area a very famous site.

That is difficult. I think that other palynologists and biologists should answer that. I had a lot of pleasure, of course, in the studies we started in Colombia. After I finished my thesis work on the vegetation and climate development in the last glacial and late glacial, I started my work in Colombia. That was really the start of tropical palynology. Jan Muller started also at that time. He was working for Shell. He started also doing work in the tropics. But, really there was nothing done before on pre-Pleistocene sediments. We started with the upper Cretaceous and the Tertiary of northern Southern America. We had to think about the nomenclature and how we would describe the great number of species of pollen and spores we found.

Ever since then, we tried to interpret the data in a stratigraphic, but also in an ecological way. I think that in that time a lot of identifications were generated that are still very interesting and a contribution to paleopalynology. Later we studied a number of sections in the Plio-pleistocene of South America, where one of the most important things was the discovery of very long sections. We had in the Sabana de Bogotá in the high plane of Bogotá, lake sediments which represented 3 million years of continuous history. That work was later continued by people such as Henry Hooghiemstra. I think that is an important contribution to the history of climate and vegetation.

Finish? You never finish a research. (laughter) You only go on. As a matter of fact at this moment I am not analyzing pollen. I have a lot of students of mine who continue the work in South America and in Europe. I myself am not counting, but I am working with the data of palynology, as a matter of fact. I am still writing books and publications to try to give new visions of interesting progress in the geology and palynology of the history of, for instance, the Amazon area. I am still working on that. There are students here in the Colombian National University who are analyzing, and we are making a very interesting study of the Tertiary history of the upper Amazon Basin.

Fuquene is a still-existing lake on the high plains of the Cordillera at approximately 2540 m. The first sections were collected in the 50's and we obtained history of some 30,000 years. Now my successor Henry Hooghiemstra in Amsterdam is making a new and deep hole that we hope can represent some 150,000 years or so that can be analyzed in very great detail with 10-20 year resolution. That can be a very important contribution to the study of climatic global change, that has become very important in the last years. What really happened in detail on the scale of 20 or 10 years resolution? So we can maybe better understand what is happening today in climate change.

Yes, of course. Here in South America we started our studies of the Tertiary in 1951 when I arrived here for the first time. I worked for some 8 years in Columbia, especially dedicated to the Upper Cretaceous and the Tertiary. We wanted to produce at least a general view of the development and evolution and appearance of different groups of plants for stratigraphic purposes, especially for mining and the petroleum industry. We had in that time, in 1951, the problem of how to start the nomenclature. There were several proposals about how you could describe pollen genera. It was a very interesting period, there were several different ideas and in the meantime in the Botanical Congresses it was decided how to act in fossil pollen nomenclature.

I think it was a very interesting time. I had much correspondence about it with Professor Potonie and with Iversen of how could we go on. We had at that time an idea of how we could make a consistent system of genera based on morphology only. That of course was developed and later amplified by Potonie, how to treat the pollen grains exactly like plants and follow the botanical nomenclature. That was an interesting time because it was a time of development, and in the beginning it was not clear exactly what we had to do. And all sorts of systems were proposed by different palynologists of how to make a pollen-generic system.

Well, when we were analyzing especially the upper Cretaceous and Tertiary sediments we discovered there seemed to be cyclicity in the appearance of certain groups, which seemed to indicate local changes in ecology, partly because of sea-level changes and possibly also climate, which was more difficult to be sure of. But there was some cyclicity, and we made some calculations about the periodicity of the appearance and disappearance of certain groups. We came to an approximation of approximately 6,000,000 years and 2,000,000 years. There seemed to be a relation between the moments that such cycles started and the appearance of new species. On that basis we made the theory that the cyclicity could be from outside the Earth and could be related eventually with the sun. It could perhaps be changes of radiation of different types and of energy. The Earth, of course, depends completely on the sun.

Well, it was an idea that was published in several parts, as by the New York Academy of Sciences. And, later in the beginning of the 1960's we had also a conference in Germany where the theme was discussed. Everything pointed well to the proposals of cyclicity in the Tertiary, the Cretaceous and the Jurassic, and there really seemed to be very clear indications of several periodicities on a geological scale. It was very interesting to hear, much later, two years ago, when I got a letter from paleontologists of the United States who had found very similar things in the sequence of the evolution of mammals. They found very similar values in cyclicity. I think this is a very interesting issue. It coincides with recent developments in sequence stratigraphy. I think that in the future it should be studied and elaborated because it may be a very important line of research in the future that may help us also in age determination as well as in understanding certain processes of evolution.

Well I thank you very much. It has been very interesting to have had palynology as the basic science in the research we have been doing. It has given me much satisfaction through all my life, and behind that is probably the fact that I have been working in two fields at the same time that interest me very much - both geology and biology.

AASP Newsletter 12(2): p. 7, 1989.

PROFESSOR THOMAS VAN DER HAMMEN RETIRES

On September 29th, 1989, Thomas van der Hammen (65) took his leave as Professor in Palynology and as leader of our research group 'Palynology and Palaeo-Actuoecology' at Amsterdam University. On the occasion of his leave he gave his last lecture in the monumental aula of the University, entitled "Ice age and nun forest. The Amazon basin and the Andean mountains as part of the earth's dynamic ecosystem." This lecture was preceded in the morning by a minisymposium entitled "Tropical Rain Forest and Paleoclimate." Four speakers (Dr. Servant, France; Dr. Hooghiemstra, Netherlands; Dr. Lauer, Germany; and Dr. Prance, Great Britain) addressed topics which have always been of great interest to Thomas. A series of publications, dedicated to this extremely dynamic person by many of his pupils, will be published soon in the international journals Acta Botanica Neerlandica and Geologie en Mijnbouw. Her Majesty, the Queen of The Netherlands, awarded him the order of knighthood.

Van der Hammen studied geology and botany at Leiden University.

Among his teachers were Florschutz and van der Vierk. After his doctoral examination, he remained at the laboratory of the Geological Survey in Copenhagen for some time, where Johannes Iversen taught him modern pollen morphology and botanical- and paleoecology. His Ph.D. thesis "Late-glacial flora and periglacial phenomena in the Netherlands" (1951) was a landmark in the study of the European Late Glacial. From 1951 till 1959 he worked in Colombia at the Geological Survey in Bogota, where he initiated palynological studies on sediments of Cretaceous, Tertiary and Quaternary age. He also performed studies on floristics and vegetation of northern South America, and taught palynology, paleobotany and geology at several universities in Bogota. In the period from 1959 till 1966 he continued his pioneering research in Quaternary geology and paleoclimatology at Leiden University with European and South American sediments.

In 1966 he became an Associate Professor and later Professor in Palynology at the Hugo de Vries Laboratory, University of Amsterdam. He supervised the Ph.D. programs of about 40 students. Being an enthusiastic and inspiring leader of a team of scientists, he realized many research projects in Amsterdam. Under his guidance the palynological research group was fused with the botanical-ecological group. This combination of research group was fused with the botanical-ecological group. This combination of research fields appeared very fruitful in van der Hamrnen's hands, and especially in Colombia integrated paleo/actuoecological research (Ecoandes project) was carried out. The wealth of results of these transect studies are published in the series Studies on Tropical Andean Ecosystems, of which three volumes have already appeared.

During his career Professor van der Hammen participated, often with an invitation, in many international congresses where he, as a talented speaker, could present the data of his successful research. He was appointed to membership in the Colombian and Danish Academy of Sciences.

We have known Thomas van der Hammen for more than 20 years. He can be characterized as a creative, optimistic, inspiring, energetic, stimulating and intelligent person. We hope that the new phase in his life may be of long duration and scientifically rewarding.

Bas van Geel
Henry Hooghiemstra
University of Amsterdam