Category: Uncategorized

THREE IN THE BED. "Progressive or sequential senescence occurs during vegetative growth in herbaceous species when continued leaf production at the stem apex is frequently at the expense of the senescence of preceding leaves on the shoot. For example, in certain temperate pasture grasses, each vegetative branch (tiller) generally carries about three mature leaves at any given time, and every new leaf that appears must be balanced by senescence of the lowermost leaf." https://lnkd.in/dPac2Jv View in LinkedIn

ALL ABOUT INFORMATION. "A major evolutionary transition has been most broadly defined as a change in the way that heritable information is stored and transmitted." Think this over. http://www.pnas.org/content/112/33/10112.full View in LinkedIn

SHUNTING THE GOODIES. "Internal redistribution of N between sources and sinks can also account, at least in part, for other patterns of senescence. Before leaf fall in deciduous species, salvaged N is transferred to bark tissues, where it accumulates as defined storage proteins that will be mobilized to provide amino acids to support the resumption of growth in the spring." https://lnkd.in/dPac2Jv View in LinkedIn

REPETITIVE CHALLENGE. "The major transitions approach provides a conceptual framework that facilitates comparison across pivotal moments in the history of life. It suggests that the same problem arises at each transition: How are the potentially selfish interests of individuals overcome to form mutually dependent cooperative groups?" http://www.pnas.org/content/112/33/10112.full View in LinkedIn

AUTO-DIGESTION. "Young, actively growing vegetative sinks, and storage organs accumulating reserve proteins, have a rapacious appetite for N. When the demand cannot be met by import from the rhizosphere alone, N is withdrawn from older tissues. In extreme cases – monocarpic reproduction, for example – N remobilization from older tissues can occur on such a scale that the plant ‘self-destructs’." https://lnkd.in/dPac2Jv View in LinkedIn

LIFE AS A SERIES OF COLLABORATIONS. "In each transition, a group of individuals that could previously replicate independently cooperate to form a new, more complex life form. For example, genes cooperated to form genomes, archaea and eubacteria formed eukaryotic cells, and cells cooperated to form multicellular organisms." http://www.pnas.org/content/112/33/10112.full View in LinkedIn

TRANSITIONS. "Twenty years ago, Maynard Smith and Szathmáry revolutionized our understanding of life on earth by showing how the key steps in the evolution of life on earth had been driven by a small number of “major evolutionary transitions.” http://www.pnas.org/content/112/33/10112.full View in LinkedIn

2ND DRIVER. "Second, comparative genomic analysis reveals numerous cases of recruitment of genes with essential functions in cellular life forms, including those that enable evolutionary transitions." https://lnkd.in/dwWBEqU View in LinkedIn

1ST DRIVER. "Selfish elements drive evolutionary transitions at two distinct levels. First, mathematical modelling of evolutionary processes, such as evolution of primitive replicator populations or unicellular organisms, indicates that only increasing organizational complexity, e.g. emergence of multicellular aggregates, can prevent the collapse of the host–parasite system under the pressure of parasites." Re-read and digest. https://lnkd.in/dwWBEqU View in LinkedIn

GENETIC PARASITES. "All or nearly all cellular life forms are hosts to diverse selfish genetic elements with various levels of autonomy including plasmids, transposons and viruses. I present evidence that, at least up to and including the origin of multicellularity, evolutionary transitions are driven by the coevolution of hosts with these genetic parasites along with sharing of ‘public goods’." https://lnkd.in/dwWBEqU View in LinkedIn