Topic description / abstract:
The evolutionary role of environmentally induced phenotypic variation, i.e. environmental plasticity, is an important issue in developmental evolution. One of the major physiological responses to environmental changes is cellular stress, which is counteracted by a generic stress reaction detoxifying the cell, refolding proteins, and repairing eventual DNA damage. In this contribution I will elaborate on a previous finding suggesting that the cell differentiation cascade of human decidual stromal cells, a cell type critical for embryo implantation and the maintenance of pregnancy, evolved from a cellular stress reaction. These results suggest that the stress reaction in these cells was ancestrally elicited by the inflammation caused by embryo attachment and invasion. This leads to a scenario, Stress Induced Evolutinoary Innovation (SIEI), in which the ancestral stress reaction was transformed into the phenotype of a novel cell type, the decidual stromal cell. I will be arguing that SIEI is a distinct form of plasticity based evolutionary change. The distinguishing feature being that SIEI leads to novel cell types, rather than directly to the adaptive transformation of a pre-existing character. The similarities and differences of SIEI and he “plasticity first hypothesis” of evolution will be discussed.
Günter Wagner is the Alison Richard Professor of Ecology and Evolutionary Biology at Yale University. He is a chemical engineer by training and studied zoology and mathematics at the University of Vienna where he earned a Ph. D. in zoology. From 1985 till 1991 he was at the Department of Zoology at the University of Vienna, Austria and in 1991 joined Yale’s Department of Biology. In 1997 he became the first chair of Yale’s Department of Ecology and Evolutionary Biology. Since 2010 he is a member of the Yale Systems Biology Institute. His research interests include population genetics, the evolution of gene regulation, the evolution of pregnancy, and the evolutionary medicine of cancer and female sexuality. GPW is a Mac Arthur Fellow, member of the US National Academy of Sciences, the American Academy of Arts and Sciences and a corresponding foreign member of the Austrian Academy of Sciences.