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Thanks! > Death by old age is mostly a problem of the multicellular living beings (where only a small fraction of their cells are converted into the cells of n

by dsign 2y ago

Thanks! > Death by old age is mostly a problem of the multicellular living beings (where only a small fraction of their cells are converted into the cells of new young descendants), so it is not something that affects the majority of bacteria. Yes, and I know that there are multicellular organisms where senescence is pretty much a non-issue (hydra). Senescence is two processes running in parallel: one is "bad luck" crippling the capabilities of a system. For example, a gene loses functionality after an error during replication. In general, it can happen that a subsystem strands in a part of its state space that it can not exit from, and this could happen even to single-cell organisms. The second process is a response to the first, and it is a set of evolved mechanisms that increases the fitness and/or average life-expectancy of an organism by preemptively shutting down the most fragile subsystems, the ones which are likely to fail early anyway. Now, these are evolved systems, not designed. They work in an all-is-good-as-long-as-the-species-survives basis. And so comes the heretic question: what happens if the system is engineered? Can we develop and possess algorithms and workflows to design organisms with longer lifespans? Doing so for M. Genitalium is not going to do anything for humans, but once that ball is rolling, we may want to keep pushing the envelope and aiming for bigger and bigger model organisms, until we get to Canis familiaris. Then we pretty-promise to stop.

adrian_b 2y ago
For now, we still do not have a complete understanding of any living cell. The mycoplasmas have some of the simplest possible cells, so, as you suggest, they are good candidates for the first cells whose organization and functions will become completely known. While it is unlikely that understanding a mycoplasma would provide direct information about the causes of senescence in any multicellular organism, there is no doubt that when either a mycoplasma or another of the simplest bacteria will become completely known, that will bring a huge jump in the knowledge about all living beings and from that moment on it will become much easier to discover the causes of senescence and how it might be prevented. There are bacteria that have extraordinarily efficient mechanisms for DNA repair, so there is no doubt that it should be possible to improve the design of human cells to avoid the accumulation of genetic errors. However, this will not happen in a few years, but in at most a century from now it is very likely that this would be possible.

by dsign 2y ago

adrian_b 2y ago

For now, we still do not have a complete understanding of any living cell. The mycoplasmas have some of the simplest possible cells, so, as you suggest, they are good candidates for the first cells whose organization and functions will become completely known. While it is unlikely that understanding a mycoplasma would provide direct information about the causes of senescence in any multicellular organism, there is no doubt that when either a mycoplasma or another of the simplest bacteria will become completely known, that will bring a huge jump in the knowledge about all living beings and from that moment on it will become much easier to discover the causes of senescence and how it might be prevented. There are bacteria that have extraordinarily efficient mechanisms for DNA repair, so there is no doubt that it should be possible to improve the design of human cells to avoid the accumulation of genetic errors. However, this will not happen in a few years, but in at most a century from now it is very likely that this would be possible.