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SO ENDS this first of two weekends thinking about what is behind the incredible diversity of flower forms. The comparative anatomy of flowers, which would fill volumes, only makes sense when considered from both an evolutionary and a developmental perspective, and fortunately, the genetics behind flower shape have been greatly illuminating, and surprisingly simple at its base. View in LinkedIn

Europe plans ban on plastic cutlery, straws and more http://money.cnn.com/2018/05/28/news/europe-plastic-ban-proposal/index.html View in LinkedIn

PURGING AND UNMASKING. "That said, haploid meiotic products have the advantage of allowing the “purging” of deleterious alleles and the “unmasking” of potentially adaptive recessive alleles, both clear benefits of the modern version of meiosis." https://lnkd.in/ebVhXPf View in LinkedIn

FALSE PREMISE. "There is no basis to the claim that the original meiotic products were haploid, other than the parsimony argument that because they are so now then they may also have been so when they originated." https://lnkd.in/ebVhXPf View in LinkedIn

PLOIDY TRANSITION. "It is worth noting explicitly that original versions of meiosis may have taken tetraploids to diploids rather than diploids to haploids, or octoploids to tetraploids for that matter because the key metric is ploidy transition rather than absolute ploidy level." https://lnkd.in/ebVhXPf View in LinkedIn

UNIQUE FEATURE. "For this to succeed, mechanisms promoting sister chromatid cohesion were required. The unique feature of meiosis compared with mitosis is meiosis I in which chromosome homologs rather than sister chromatids segregate in a reductional division." https://lnkd.in/ebVhXPf View in LinkedIn

HALLMARK OF MEIOSIS. "A key innovation—indeed, the hallmark of meiosis—was synapsis between homologs." https://lnkd.in/ebVhXPf View in LinkedIn

SURVIVAL MECHANISM. "Notably, other types of DNA lesions, such as abasic sites or nicks generated by DNA deaminase acting to convert cytosine to uracil (a substrate for uracil N-glycosylase), can restore meiotic recombination in mutants of the fission yeast Schizosaccharomyces pombe lacking Spo11 (rec12) without generating double strand breaks." https://lnkd.in/ebVhXPf View in LinkedIn

COMPETITIVE ADVANTAGE. "Such a model is supported by the finding that the meiotic defects of S. cerevisiae spo11 mutants can be in part suppressed by gamma irradiation, suggesting that random double strand breaks can suffice to enhance meiotic crossovers and increase spore viability and germination." http://cshperspectives.cshlp.org/content/6/3/a016154.full View in LinkedIn

HYPOTHESIS. "Perhaps the most interesting hypothesis for why replication occurs before meiotic recombination in meiosis I is that in the pre-Spo11 era, the sister-chromatid copies served as the source of double strand breaks. Double strand breaks are formed by replication of nicked DNA, in which the nicks might have been incurred by UV or gamma rays before Spo11, and double strand breaks (but not nicks) are potent stimulators of homologous recombination." https://lnkd.in/ebVhXPf View in LinkedIn