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DEATH FOR INCREASED FITNESS. "Programmed cell death (PCD) serves the interests of multicellular organisms in many ways. Because it increases the fitness of the organism, there is no mystery about the function of PCD in plants and animals." View in LinkedIn

REGULATED DEATH. “In all cases that have been studied to date, programmed cell death is regulated by signals provided by other cells, either in the form of cell-lineage information, of soluble mediators, or of cell-to-cell contacts." http://www.nature.com/cdd/journal/v9/n4/full/4400950a.html View in LinkedIn

WIDELY CONSERVED. “Programmed cell death has been found to operate in all multicellular animals studied so far, including cnidaria, nematodes, insects, amphibians, birds and mammals. The evolutionary conservation of programmed cell death in the animal kingdom does not only involve its existence and role, but extends to some central aspects of its genetic control, and to important aspects of its most frequent phenotype, apoptosis." http://www.nature.com/cdd/journal/v9/n4/full/4400950a.html View in LinkedIn

APOPTOSIS and cell suicide are continuous ongoing processes in living systems. It is normal and widespread. "The cells of a multicellular organism are members of a highly organized community. The number of cells in this community is tightly regulated—not simply by controlling the rate of cell division, but also by controlling the rate of cell death. If cells are no longer needed, they commit suicide by activating an intracellular death program." https://lnkd.in/eaj7Brc View in LinkedIn

SELECTION BEYOND THE INDIVIDUAL. "However, unicells undergoing POD do not leave any direct descendants. Thus, in unicells, POD (with the possible exception of autophagy) may involve adaptation through function, and selection, at levels other than the individual organism." (POD = programmed organismal death). http://www.esciencecentral.org/journals/are-internal-death-promoting-mechanisms-ever-adaptive-2329-9002.1000113.pdf View in LinkedIn

PLAUSIBLE IDEA. "However, if the unicellular organisms have the ability to recognize their kin, or simply tend to live in close proximity of each other, then this argument is no longer valid: One can easily envision that a unicellular organism could kill itself for the better good of its neighboring relatives, thus furthering the survival and multiplication of its own genes." https://lnkd.in/dVeZ2yE View in LinkedIn

DEATH AS A SIDE-EFFECT? "We must ask of unicellular organisms the same question we asked about multicellular organisms: Is death the function of POD, or merely a side effect? Multicellular organisms undergoing POD typically do leave offspring, so active death that is a byproduct of mechanisms “designed” to regulate investment in reproduction is a viable (and often supported) hypothesis for multicellular POD." (POD = programmed organismal death). http://www.esciencecentral.org/journals/are-internal-death-promoting-mechanisms-ever-adaptive-2329-9002.1000113.pdf View in LinkedIn

IMPLAUSIBLE IDEA. "It has been argued that for unicellular organisms, there would a priori appear to be no need for such a program, as cell death basically translates into organismal death and therefore would confer no evolutionary advantage (dead organisms do not procreate)." https://lnkd.in/dVeZ2yE View in LinkedIn

REF FOR TODAY’S POST. Are Internal, Death-Promoting Mechanisms Ever Adaptive?" "John W Pepper, Deborah E Shelton, Armin Rashidi and Pierre M Durand" "Journal of Phylogenetics & Evolutionary Biology View in LinkedIn

DEPTH AND DEFINITIONS. "How far “down” the evolutionary ladder one can expect programmed cell death to exist depends on how one defines the phenomenon." https://lnkd.in/dVeZ2yE View in LinkedIn