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ALTERNATIVE HYPOTHESIS, A BYPRODUCT. "We investigate an alternate hypothesis that has been suggested, but heretofore untested, which is that modularity evolves not because it conveys evolvability, but as a byproduct from selection to reduce connection costs in a network." https://lnkd.in/eX5AfaH View in LinkedIn

HYDROGEN AND HELIUM LINEAGE. “Supernova nucleosynthesis is a theory of the production of many different chemical elements in supernova explosions. The nucleosynthesis, or fusion of lighter elements into heavier ones, occurs during explosive oxygen burning and silicon burning processes. Those fusion reactions create the elements silicon, sulfur, chlorine, argon, sodium, potassium, calcium, scandium, titanium and iron peak elements: vanadium, chromium, manganese, iron, cobalt, and nickel. These are called "primary elements", in that they can be fused from pure hydrogen and helium in massive stars.” https://lnkd.in/eFGMPQy View in LinkedIn

BIRTH OF ELEMENTS. “Stellar nucleosynthesis is the process by which the natural abundances of the chemical elements within stars change due to nuclear fusion reactions in the cores. A star loses most of its mass when it is ejected late in the star's lifetime, thereby increasing the abundance of elements heavier than helium in the interstellar medium. The term supernova nucleosynthesis is used to describe the creation of elements during the evolution and explosion of a pre-supernova star, a concept put forth by Fred Hoyle in 1954.” https://lnkd.in/eEjZ4jp View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend on the synthesis of the biogenic and other chemical elements. At the heart of the matter of the universe that we can see and touch (about 5%) are protons. Add protons and you get different elements. Dying stars are proton adding factories, churning out elements, the bits that make you and me. View in LinkedIn

ASYMMETRICAL ARMS RACE. "We apply this theory to explain a longstanding paradox in biology and medicine: the evolution of excessive defences against enemies. These so-called extraordinary defences can evolve in response to asymmetrical selection when marginal risks of insufficient defence exceed marginal costs of excessive defence." https://lnkd.in/e5R5vQe View in LinkedIn

ASYMMETRIC SELECTION. “Examples of asymmetric selection include human birth weight, parasitic gall size, and bill depth in Darwin’s finches." https://lnkd.in/e5R5vQe View in LinkedIn

SYMMETRIC SELECTION. “Although examples of symmetric stabilizing selection exist (for example, Bumpus’ sparrows), many individual fitness distributions are skewed." https://lnkd.in/e5R5vQe View in LinkedIn

ADDING ASYMMETRY. "Here we revisit Lande’s adaptive landscape and introduce novel analytical theory that includes asymmetric selection. Asymmetric selection and the resulting skewed trait distributions bias equilibrium mean phenotypes away from fitness peaks, usually toward the flatter shoulder of the individual fitness surface." https://lnkd.in/e5R5vQe View in LinkedIn

ADAPTIVE LANDSCAPE. "Lande’s analytical approach is commonly used to describe the evolution of the mean phenotype on an adaptive landscape. Lande showed that an evolving population climbs the adaptive landscape to a local fitness peak through evolution." https://lnkd.in/e5R5vQe View in LinkedIn

DEVIATIONS FROM SYMMETRY. "Evolutionary biologists typically predict future evolutionary responses to natural selection by analysing evolution on an adaptive landscape. Much theory assumes symmetric fitness surfaces even though many stabilizing selection gradients deviate from symmetry." https://lnkd.in/e5R5vQe View in LinkedIn