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Aging in Single-celled Organisms: from Bacteria to the Whole Tree of Life/LinChao

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Notes by user Lin Chao (UC San Diego) for Aging in Single-celled Organisms: from Bacteria to the Whole Tree of Life

Post-meeting Reflection

1+ paragraphs on any combination of the following:

  • Presentation highlights
  • Open questions that came up
  • How your perspective changed
  • Impact on your own work
  • e.g. the discussion on [A] that we are having reminds me of [B] conference/[C] initiative/[D] funding call-for-proposal/[E] research group


A. What is aging? Classical definition from Medawar aging is passage of time and aging is the deterioration of function with time. Aging and senescence is nowadays used to mean equivalently the deterioration with time. We will used aging and senescence in this more contemporary context, and refer to the passage of time specifically as chronological aging. However, because in some organisms the deterioration can be reversed, we will describe those instances as reversed or positive senescence or aging (discuss?).

B. Following Medawar, we also can distinguish aging that results from wear and tear from interactions with the environment much as a automobile parked by the ocean will rust and fragment. However, because the hallmark that distinguishes physical objects such as a car and a biological organism is the latter's ability to change through evolution by natural selection, aging can be accelerate in living systems beyond physical wear and tear. The acceleration results from the production of asymmetrical daughters by dividing mother cells. While the asymmetry can result from a combination of factors, some beneficial and others deleterious, a possible cause may be damaged cellular molecules and organelles. The daughter that receives more damage ages and the other rejuvenates. The aging daughter can be viewed as the continuation of the mother, the daughter receiving less can be regarded as the new juvenile offspring. This concept can be extended to metazoans and the asymmetry

Reference material notes

Some examples:

  • Here is [A] database on [B] that I pull data from to do [C] analysis that might be of interest to this group (insert link).
  • Here is a free tool for calculating [ABC] (insert link)
  • This painting/sculpture/forms of artwork is emblematic to our discussion on [X]!
  • Schwartz et al. 2017 offers a review on [ABC] migration as relate to climatic factors (add the reference as well).

Reference Materials