Historical Development
The concept of the morphogenetic field, fundamental in the early twentieth century to the study of embryological development, was first introduced in 1910 by Alexander G. Gurwitsch. Experimental support was provided by Ross Granville Harrison's experiments transplanting fragments of a newt embryo into different locations.
Harrison was able to identify "fields" of cells producing organs such as limbs, tail and gills and to show that these fields could be fragmented or have undifferentiated cells added and a complete normal final structure would still result. It was thus considered that it was the "field" of cells, rather than individual cells, that were patterned for subsequent development of particular organs. The field concept was developed further by Harrison's friend Hans Spemann, and then by Paul Weiss and others.
By the 1930s, however, the work of geneticists, especially Thomas Hunt Morgan, revealed the importance of chromosomes and genes for controlling development, and the rise of the new synthesis in evolutionary biology lessened the perceived importance of the field hypothesis. Morgan was a particularly harsh critic of fields since the gene and the field were perceived as competitors for recognition as the basic unit of ontogeny. With the discovery and mapping of master control genes, such as the homeobox genes the pre-eminence of genes seemed assured. But in the late twentieth century the field concept was "rediscovered" as a useful part of developmental biology. It was found, for example, that different mutations could cause the same malformations, suggesting that the mutations were affecting a complex of structures as a unit, a unit that might correspond to the field of early 20th century embryology.
Scott Gilbert proposes that the morphogenetic field is a middle ground between genes and evolution. That is, genes act upon fields, which then act upon the developing organism. Jessica Bolker describes morphogenetic fields not merely as incipient structures or organs, but as dynamic entities with their own localized development processes, which are central to the emerging field of evolutionary development ("evo-devo").
Read more about this topic: Morphogenetic Field
Famous quotes containing the words historical and/or development:
“Some of us still get all weepy when we think about the Gaia Hypothesis, the idea that earth is a big furry goddess-creature who resembles everybodys mom in that she knows whats best for us. But if you look at the historical recordKrakatoa, Mt. Vesuvius, Hurricane Charley, poison ivy, and so forth down the agesyou have to ask yourself: Whose side is she on, anyway?”
—Barbara Ehrenreich (b. 1941)
“For decades child development experts have erroneously directed parents to sing with one voice, a unison chorus of values, politics, disciplinary and loving styles. But duets have greater harmonic possibilities and are more interesting to listen to, so long as cacophony or dissonance remains at acceptable levels.”
—Kyle D. Pruett (20th century)