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Tuesday, 29 December 2015

Life: survival versus reproduction

1.       Life is often thought of and analysed from the viewpoint of the individual organism. In a previous post (The Apparent Complexity in Life’s Evolution and Its Explanation ), I suggested defining life as a process rather than an organism, therefore clarifying tricky areas such as viruses and their status of being alive or not, and other life products that may be alive in some situations that are very conditional e.g. seeds.

In attempting to explain life from the viewpoint of the individual organism, the basic function of life appears to be survival of the organism. There have been plenty of discussions over the fundamental unit of life in the context of evolution, that have suggested various “vehicles” of life information including genes themselves, species, populations (Jablonka and Lamb, 2006), etc.

The issue of course with this viewpoint is that organisms always die. Life clearly has no interest whatsoever in the actual survival of any given organism into infinity by itself. Indeed, the same can easily be extended to species. Life has thrived not through survival of any given individual organism or species at all, and instead, through survival of life processes spanning countless individual organisms and species. This entire show has been sponsored by reproduction.

2.       Reproduction in the context of life is better or easier than plain survival – but what is it better at?
It is better at providing the opportunity for adaptation. Life cannot exist in a vacuum, and if life is to be a complement of non-life, of the environment, it must be able to change, to update, through time and space as the universe is doing.
The directionality of time explains why reproduction makes more sense than mere survival ad infinitum. Each cycle, each generation, is a change. And starting to change from square one, developmentally speaking, is far more straightforward than starting to change from square 47. Getting babies and children to learn slightly differently, or gain some new abilities that are new, is easier than getting a mature, further down the line organism to do the same.
After all, adults will have always been selected for as babies for their ability to be adapted to their present, but not the unknown future. The only way, apparently, to greet the future, the unknown pressures, is to renew the organism, or indeed the genome, via reproduction.

3.       Sexual reproduction has often been discussed as the great enabler of diversification, mutation, evolution. What about asexual reproduction? What is the point in reproducing oneself if the result is merely clones all over again? Why make them rather than simply maintain the already existing organisms?

It isn't just the diversification offered by sexual reproduction that enables life through reproduction; it is also merely the process of repeating a developmental pathway, be it a different one or the exact same one all over again, as it is in asexual reproduction.

Cycling life, which is defined as certain processes distinct from non-life, has been much easier, more environmentally or energetically amenable than producing and maintaining individual organisms themselves ad infinitum. This matter comes into sharp focus when discussing ageing, death and the role of life’s evolution in shaping organisms, reproduction, as well as potential directions to be taken by civilizations to offset these evolved truths in an attempt to break them and move forward into something else, away from past directions.

4.       The point at which we will be able to offset the reliance of life on reproduction in its original, or current, sense, is the point at which we are able to enact changes, adaptations, of mature organisms, that are at least as efficient as "natural" changes that occur in reproduction. 

This could be things like manipulating the genome, developmental paths, tissues and functions, etc. 

This obviously is a grand challenge. 

After all... Life hasn't been doing nothing all this time. Or indeed, time hasn't been doing nothing all this life. 


Reference

E. Jablonka and M. Lamb (2006), Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life, MIT Press, ISBN 978-0262600699

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