Year: 2022

NATURALISM. “The traditional asthetic of embryology has been naturalism. Every species develops in a different manner, and generalizations from one species to another are very risky. So aesthetically, embryology is to molecular biology as a Michaelangelo statue is to a Brancussi.” https://lnkd.in/dQuxg6Y View in LinkedIn

THE FEAR. “One of the reasons that molecular biology has taken so long to enter embryology is the longstanding fear among embryologists that genetics—whether it be classical genetics or molecular biology—is trying to take over their discipline and bring with it all its reductionism and lack of appreciation for the complexity and species differences.” https://lnkd.in/dQuxg6Y View in LinkedIn

THE GRADUAL INVASION. “Embryology was redefined as the study of changes in gene expression over time, and evolution was redefined as changes in gene frequency over time. Thus, evolution and embryology, which had traditionally been sciences of the phenotype, were given new, genotypic, definitions. These new definitions went against the prevailing paradigms of these fields.” https://lnkd.in/dQuxg6Y View in LinkedIn

CONSEQUENCES. “The predominant problem of embryology from the 1700s through the 1950s was the creation of ordered form, morphogenesis, not differentiation. Morphogenesis was a whole-embryo question, differentiation a cellular question. The genetic redefinition of embryology collapsed the morphogenesis question into a subset of the cell differentiation question.” https://lnkd.in/dQuxg6Y View in LinkedIn

TAKEOVER BY GENETICS. “Note how embryology's main question is said to be differentiation, not morphogenesis. Note also how genetics can now take over this question. Embryology is being reduced to genetics. And why not, since the geneticists will write that they have the superior methodology.” https://lnkd.in/dQuxg6Y View in LinkedIn

HIGHER GROUND. “After this separation of genetics from embryology, the geneticists defined themselves against embryology. They often depicted embryology as being an intellectual backwater and saw themselves as the true heirs of Darwin and the question of heredity.” https://lnkd.in/dQuxg6Y View in LinkedIn

GOLDEN ERA. “But while the geneticists were making their great discoveries into the mechanism of hereditary transmission, the embryologists were also having their own golden era. Ignoring genetics altogether, embryologists embarked on the program which Joseph Needham (1936) christened "Gestaltungsgesetze, the rules of morphological order." https://lnkd.in/dQuxg6Y View in LinkedIn

FIELDS NOT GENES. “The evidence gave coalesced into a concept called the morphogenetic field, and this morphological unit, rather than the gene, was seen as being the fundamental unit of development (and in the case of planaria, inheritance).” https://lnkd.in/dQuxg6Y View in LinkedIn

CYTOPLASMIC SCIENCE. “Indeed, the concept of gene expression is absent in the major embryology books of the 1920s through the 1940s. Although experimental embryology had successfully separated itself from the earlier traditions of developmental anatomy, it remained a phenotypic science, and it identified itself as a science concerned with cytoplasmic changes.” https://lnkd.in/dQuxg6Y View in LinkedIn

CELLULAR SEPARATION. “As Frank R. Lillie wrote in his critical review of 1927, "The germ exhibits the duality of nucleus and cytoplasm; the geneticist has taken the former for his field, the embryologist the latter." https://lnkd.in/dQuxg6Y View in LinkedIn