Year: 2022

3D PHYSICS. “We do not yet know of any such 3-D theory that works in that way. Indeed, what surface should we use as the boundary of the universe? One step toward realizing these ideas is to study models that are simpler than our real universe.” https://lnkd.in/draqjTW View in LinkedIn

BUILDING COMPLEXITY FROM SIMPLICITY. “I argued with him, saying that hierarchically organized stereochemistry, acting according to the key-lock rule, plus electrochemistry as an ornament is an ample basis for the realization of life processes (just like any of the most primitive alphabet is an ample base for expressing the most complex thoughts)". A.D. Sakharov (2011) https://lnkd.in/da7dRTF View in LinkedIn

The gorgeous lime tree flowers, framed by their silver undersided leaves, are scenting the roads of Girona. View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend and concludes this weekend on a wonderful article about the history of the differences in philosophy between geneticists and embryologists that led to conflicts before the two disciplines came together. The two groups were founded in reductionism and holism respectively, and the two viewpoints were largely unreconcilable. Because of this they took up different camps in the cell and followed different theories. https://lnkd.in/dQuxg6Y View in LinkedIn

THE PROBLEM OF PERMEABILITY. “However, the nuclear envelope proved to be a permeable barrier. More and more, geneticists began to see some form of differential gene activity as the cause for embryogenesis. Jumping over the nuclear boundary, they claimed embryology as part of their domain as well.” https://lnkd.in/dQuxg6Y View in LinkedIn

THE HURDLE. “Genes could not be relevant to embryology until geneticists could explain how identical genes could generate different types of cells. In 1934, T. H. Morgan speculated that every gene, even though present in every cell, might not be active in every cell.” https://lnkd.in/dQuxg6Y View in LinkedIn

MORGAN OVERCAME THE HURDLE. “Cells that contain different types of cytoplasm would be able to activate different batteries of genes.” https://lnkd.in/dQuxg6Y View in LinkedIn

NUCLEAR VS CYTOPLASMIC. “Other biologists, notably Haldane (1932) and Goldschmidt (1939) were also postulating that genes acted at different times during development; but they did not place so much value on the cytoplasmic feedback. This may be a pleasant hypothesis, but there was no evidence in its favor.” https://lnkd.in/dQuxg6Y View in LinkedIn

REDEFINITION. “The evidence that differentiation is caused by the differential expression of batteries of genes from identical genomes came from the study of unicellular organisms. Differentiation is to be seen not in terms of tissue structure but "as the controlled production of unique enzyme patterns." This redefinition, he stated, would focus our attention on "the relationship between the genes in the nucleus and the properties of the cytoplasm." https://lnkd.in/dQuxg6Y View in LinkedIn

SUPPORT. “The Beadle and Tatum's studies in Neurospora “showed that an altered genotype creates altered enzymatic properties in the cytoplasm. Enzymes were the link between genotype and phenotype. Genes controlled the production of enzymes; enzymes controlled the phenotype of the cell.” https://lnkd.in/dQuxg6Y View in LinkedIn