The Origin of Life



One possible objection to the idea that populations come to utilise their resources with increasing efficiency is that populations are fundamentally lacking in harmony - by virtue of being divided into discrete individuals with conflicting objectives.

I think it is worth examining this issue before going any further.

There are a number of sorts of inefficiency involved:

  • Prudent predator

    The discussion of whether ecosystems succeed in maximising energy flow through them in the long term has been previously discussed under the rubric of the "prudent predator".

    A group of prudent predators refrains from consuming too many prey - in order to preserve a healthy breeding population, for use on future occasions.

    This necessarily involves individual predators refraining from destroying prey - in order to avoid depleting prey numbers to the point where the next generation of predators suffers starvation.

    If the predators succeed in refraining from over- exploitation of their resources, they are described as "prudent" - and making "efficient" use of their prey.

    The benefit of eating one of the few remaining prey individuals is immediate and accrues to the individual who eats it. The cost of not being able to eat all that organisms descendants is less immediate - and is borne by the group.

    It appears that many predators are not prudent. They selfishly maximise short-term benefit to themselves - and drive the ecosystem they are part of into a cycle of fluctuations which resucts in a less stable population for all concerned.

  • Tragedy of the commons

    The tragedy of the commons [1] arises when a resource is available to all, but an individual gains from his exploitation of it - wheras the cost of having the resource exploited is paid by everyone.

    The classic example is a pasture. Individuals benefit from having more animals grase the pasture, but having the pasture over-grazed causes everyone severe problems.

    A common result is that everyone tries to reap maximum benefit from the pasture by grabbing as much for themselves as possible - but the result is that the pasture is soon depleted - and the animals all starve.

    It can be seen that the problem of the prudent predator is really a type of "tragedy of the commons" problem - with the additional complication that the resource is self-reproducing.

Decreasing discord

Populations need to find ways of diminishing inefficiences within them if they are going to be successful in the long term.

There are opportunities available to them which would help them be more efficient:

  • Selection on higher levels

    While there seems to have been some success in using models of group selection to illustrate that the prudent predator is a possibility (e.g. [2]), group selection has several "traditional" problems that seem likely to result in this solution not being widely applicable.

    In particular, the formation of distinct groups in nature depends of gene flow between the populations being very low.

    In sexual populations, groups may arise and fall only rather infrequently.

    If differential group reproduction is insufficiently rapid there is a danger that individual level selection will destroy the variability between groups that group selection needs to work.

    Selection at higher levels has the best chance of working when it can prevent variation in individuals for the trait in question from occurring - by controlling how they are constructed.

    It seems that it would have a hard time doing something like that for complex, social traits - such as prudence.

    I think populations will eventually succeed in coming to terms with the "inefficiency" represented by these problems - but I don't think it should be relied on to sort the problem out - and think that the main solution lies elsewhere.

  • Social solutions

    Collective problems sometimes require collective solutions - and one way of dealing with these sorts of problem involves monitoring of the behaviour of individuals by representatives of the population - and punishing predators who are not prudent.

    Provided the cost of the monitoring is not too large - and is sufficiently widespread - this strategy can be effective at reducing the frequency of selfishness.

    This sort of mechanism can be seen in action in some places where "fishing quotas" have been imposed by authorities in an attempt to manage populations of resources that can be over-exploited.

    This type of solution has been described in some detail by Matt Ridley - in his book, The Origins of Virtue: Human Instincts and the Evolution of Cooperation [3].

  • Integration

    One way to resolve problems caused by a system being made up of components with different goals is to make the system more uniform, eliminating the conditions that cause the conflict completely.

    My example of doing this would be human mitochondria. Mitochondria have different reproductive paths to the nuclear DNA. This means, for example, that it is normally in the interests of any mitochondria in male humans to commit suicide - causing any parental investment to be diverted into females.

    It also means that selection between the (oftem thousands of) mitochondria in human cells might favour traits which are counter-productive for thi individual thay occur in [4]. Engineering the mitochondria's genes out and putting them on the nuclear chromosomes would probably solve a lot of health problems - if it could be done.

    This sort of thing can usually be done - at least in principle - by substituting a collection of organisms with a single, more harmonious super-organism.

    In the future, such collective arrangements seem more likely to be nipped in the bud. These days there is an alternative to symbiosis - if you want to take advantage of an adaptation located by another creature - you can steal their genes.


  1. The Tragedy of the Commons - Garrett Hardin (1968).

  2. Multilevel Selection and the Evolution of Predatory Restraint - Joshua Mitteldorf, David H. Croll, and S. Chandu Ravela.

  3. The Origins of Virtue: Human Instincts and the Evolution of Cooperation - Matt Ridley.

  4. Conflicting levels of selection in the accumulation of mitochondrial defects in Saccharomyces cerevisiae - Douglas R. Taylor, Clifford Zeyl, and Erin Cooke

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