Darwinism Evolution Intelligent Design

Why do one-celled organisms undergo programmed cell death? A real evolution puzzle

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Why would something so central for multicellularity as programmed cell death (PCD) appear in unicellular organisms?:

Abstract: In multicellular organisms, cells are frequently programmed to die. This makes good sense: cells that fail to, or are no longer playing important roles are eliminated. From the cell’s perspective, this also makes sense, since somatic cells in multicellular organisms require the cooperation of clonal relatives. In unicellular organisms, however, programmed cell death (PCD) poses a difficult and unresolved evolutionary problem. The empirical evidence for PCD in diverse microbial taxa has spurred debates about what precisely PCD means in the case of unicellular organisms (how it should be defined). In this article, we survey the concepts of PCD in the literature and the selective pressures associated with its evolution. We show that definitions of PCD have been almost entirely mechanistic and fail to separate questions concerning what PCD fundamentally is from questions about the kinds of mechanisms that realize PCD. We conclude that an evolutionary definition is best able to distinguish PCD from closely related phenomena. Specifically, we define “true” PCD as an adaptation for death triggered by abiotic or biotic environmental stresses. True PCD is thus not only an evolutionary product but must also have been a target of selection. Apparent PCD resulting from pleiotropy, genetic drift, or trade-offs is not true PCD. We call this “ersatz PCD.”

Durand, P.M., Ramsey, G. The Nature of Programmed Cell Death. Biol Theory 14, 30–41 (2019). https://doi.org/10.1007/s13752-018-0311-0

The paper is closed access.

It’s not clear just how the researchers think they have answered the question. Claiming that some types of PCD are “true” and others are “ersatz” doesn’t seem to answer the central question — why programmed death occurs at all.

6 Replies to “Why do one-celled organisms undergo programmed cell death? A real evolution puzzle

  1. 1
    martin_r says:

    Why programmed cell death occur at all

    DNA damage sensing, DNA proofreading, DNA repair, DNA replication checkpoints, cell membrane self-repair, programmed cell death (apoptosis) … all these features are the ultimate proof of designed life.

    None of it should exist in materialistic world where is no foresight.

    “A Real Evolution Puzzle” :))))

    For Darwinists for sure. For engineers and designers, no surprise. It would be surprising, if these features would not exist …

  2. 2
    zweston says:

    Duh, time and chance you guys! Obviously… 😉 They evolved to know that they needed to not survive so that the fittest could, duh. 😉

    This is pretty awesome stuff. I’m amazed at the self-repairing features of cells too…amazing!

  3. 3
    Bob O'H says:

    It’s not clear just how the researchers think they have answered the question. Claiming that some types of PCD are “true” and others are “ersatz” doesn’t seem to answer the central question — why programmed death occurs at all.

    It’s very clear, if you read the conclusion section of the paper.

  4. 4
    Lieutenant Commander Data says:

    Martin_r
    Why programmed cell death occur at all

    DNA damage sensing, DNA proofreading, DNA repair, DNA replication checkpoints, cell membrane self-repair, programmed cell death (apoptosis) … all these features are the ultimate proof of designed life.

    None of it should exist in materialistic world where is no foresight.

    “A Real Evolution Puzzle” :))))

    For Darwinists for sure. For engineers and designers, no surprise. It would be surprising, if these features would not exist …

    🙂 Should be illegal to become a biologist without having a Doctorate Degree in engineering.

  5. 5
    Belfast says:

    You are alway’s good for a laugh, Bob!
    The conclusion says no such thing.

  6. 6
    martin_r says:

    LCD @4

    in your case, any degree would help a lot …

    by the way, reverse engineering, this is exactly what e.g. molecular biologists do every day ..

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