Category: Uncategorized

THE NUT. "What these over-simplified formulations truly mean is that variation at a given gene causes variation in a given phenotype." https://lnkd.in/d3vzXnd View in LinkedIn

OVERSIMPLIFIED CARTOON. "It is common to find headlines expressing these simplifications, trumpeting to wide audiences the discovery of the “longevity” or “well-being” gene, that sacrifice scientific accuracy to psychological impact." https://lnkd.in/d3vzXnd View in LinkedIn

TOO SIMPLE. "Under the classical scheme, a mutation is compared to a wild-type reference, and its phenotypic effects are used to infer gene function. This framework often leads to a semantic shortcut: from a genetic change causing a variation in phenotype, it is often convenient to assimilate the corresponding gene as a causal determinant of a trait." https://lnkd.in/d3vzXnd View in LinkedIn

ALL-IMPORTANT CONTEXT. "In other words, certain GP relationships are taxonomically robust and present across a large range of species. As underlined by multiple authors, genes and environment act jointly on the phenotype, and in most cases it is impossible to disentangle the effect of one from the other." (GP = genotype-phenotype relationship). https://lnkd.in/d3vzXnd View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend on the theme of genotype to phenotype conversion, or from DNA to observable traits. We have been immersed in the all-powerful theory of genes and destiny, but the truth is rather different. The radical conclusions we are arriving at today were completely unpredictable only 50 years ago. The phenotype is crafted from a combination of genes and the environment, often across diverse species, finding similar solutions in unrelated creatures. View in LinkedIn

RADICAL THINKING. "A major discovery of the past 20 years is that variation at certain genetic loci produce comparable phenotypic variation not only in various individuals of one population, but also in extremely diverse taxa." Contemplate this apparent radical heresy before moving on. https://lnkd.in/d3vzXnd View in LinkedIn

DECEPTIVELY SIMPLE. "Three characteristics contribute to the rapid evolution of these viruses: large populations, short generation times and high mutation rates. Every mutation, which enables its carrier to evade the host’s immune system, will be (positively) selected, passed on to the next generation and distributed more widely. Influenza viruses evolve 1 million times faster than mammals. Five years of virus evolution roughly correspond to the time span, which separates humans and chimpanzees from their last common ancestor." https://lnkd.in/d8xM5QF View in LinkedIn

CONTEXTUAL EFFECTS. "Gene-by-Environment (GxE) interaction occurs when the phenotypic effect of a given genetic change depends on environmental parameters. Similarly, epistasis, or GxG interaction, occurs when the phenotypic effect of a given genetic change depends on the allelic state of at least one other locus." https://lnkd.in/d3vzXnd View in LinkedIn

STREAMLINING AND OUTSOURCING. Extreme genome reduction in symbiotic bacteria. "These symbionts have numerous features in common, such as extraordinarily fast protein evolution and a high abundance of chaperones. Together, these features point to highly degenerate genomes that retain only the most essential functions, often including a considerable fraction of genes that serve the hosts." https://lnkd.in/dx2k-vt View in LinkedIn

REDUCTIONISM LIMITATIONS. "In summary, the classical genetic reductionist approach is inherently unable to elucidate all the factors responsible for observable characteristics in the living world but is a powerful and relevant method for dissecting the genetic levers of heritable phenotypic variation." https://lnkd.in/d3vzXnd View in LinkedIn