Category: Uncategorized

SCALE OF LIFE. “Life is almost certainly the most complex and diverse physical system in the universe, covering more than 27 orders of magnitude in mass, from the molecules of the genetic code and metabolic process up to whales and sequoias. Organisms themselves span a mass range of over 21 orders of magnitude, ranging from the smallest microbes from 10(-13) g to the largest mammals and plants 10(8) g.” https://lnkd.in/eCs7eyu View in LinkedIn

FRAGMENT FROM NATURE continues from last week’s meditation on the place of life as we know it in the universe. Right now we are only sure of life on earth, but the probabilities are high that this obscure and tiny planet is not the only location of life in the universe. Our challenge is to look up and out, and be like the pilgrim in the Flammarion engraving of 1888 peering into the heavens. https://lnkd.in/eRnh42A View in LinkedIn

MULTIVALENT DISADVANTAGES. "Multivalent formation is often associated with mis-segregation of chromosomes as well as chromosomal rearrangements arising from recombination within multivalents, leading to reduced fertility and low-fitness offspring." https://lnkd.in/e2tp_G5 View in LinkedIn

UNRESOLVED UNIVERSALITY. "The question of why one order of meiotic divisions is almost universal therefore remains unresolved." https://lnkd.in/e2tp_G5 View in LinkedIn

BLUEPRINT. “This may indicate that metabolic organization is not only identical for all living organisms, but also complies with the design principles of robust and error-tolerant scale-free networks, and may represent a common blueprint for the large-scale organization of interactions among all cellular constituents.” https://lnkd.in/em_2tJm View in LinkedIn

REVERSE MEIOSIS. "In normal meiosis, homologous chromosomes are separated during meiotic division I whereas sister chromatids are separated during meiosis II. Why meiosis generally follows this order is unknown, but interestingly, meiosis can also take place in the reverse order in some species, including some flowering plants, mites, true bugs, and mealybugs." https://lnkd.in/e2tp_G5 View in LinkedIn

SCALING. “Here we present a systematic comparative mathematical analysis of the metabolic networks of 43 organisms representing all three domains of life. We show that, despite significant variation in their individual constituents and pathways, these metabolic networks have the same topological scaling properties and show striking similarities to the inherent organization of complex non-biological systems.” https://lnkd.in/em_2tJm View in LinkedIn

IMMENSE PROBLEM SOLVING. "Polyploidy with odd numbers of chromosome sets poses an even greater problem because aneuploid gametes are generally produced. However, there are some plant species where solutions to even this problem have evolved and odd-number polyploidy appears to persist stably." http://biorxiv.org/content/biorxiv/early/2016/04/28/050831.full.pdf View in LinkedIn

SONG OF DARWIN. "The more I study nature, the more I become impressed […] that the contrivances and beautiful adaptations [acquired through natural selection] transcend in an incomparable degree [those] which the most fertile imagination of the most imaginative man could suggest with unlimited time at his disposal." http://www.sciencedirect.com/science/article/pii/S0960982214003881 View in LinkedIn

TRANSITION MECHANISM. "Part of the answer seems to be a reduction in the number of COs, since multivalents can only form with at least two COs per chromosome. There is also mounting evidence for genes that have been selected to control pairing behaviour of chromosomes during meiosis, such as ph1 in hexaploid wheat and several candidate genes in polyploid." Arabidopsis." (CO = cross-overs). https://lnkd.in/e2tp_G5 View in LinkedIn