What is the most basic agenda of all living organisms?

A fundamental question in Biology is:

What do all organisms seek to maximise, in competition/cooperation with each other?

What ultimately determines whether

  • a given area of land will be occupied by forest or by grassland, and by large or small herbivores/carnivores?
  • a given volume of water will be occupied by plankton or kelp forests, and by fishes, jellyfishes, aquatic mammals, or aquatic birds?

What does the 'scoreboard' of all Life enumerate, whereby a given organism is a winner or a loser in the quest to occupy space?

This question has seldom been tackled head-on.

So, most Biologists, if put on the spot, would probably scratch their heads rather than answer immediately.

However, in all cases where I have received an answer, it has seemed unsatisfactory.

This is because the commonly-expressed answer is 'reproduction/replication'.

Most Biologists seem to think that the most basic agenda of living organisms is to reproduce.

That is to say, that all of evolution and adaptation is ultimately geared to the maximisation of reproduction/replication, before anything else.

How much explanatory value does this answer really have?

Is it not the case that reproduction is really a means rather than an end, and a mechanism rather than a purpose?

Is it not tautological (https://www.britannica.com/topic/tautology) to assume that organisms ultimately 'reproduce in order to reproduce'?

And, even if reproduction is the ultimate criterion for the competitive/cooperative success of organisms, how could we measure it comparatively? What is the relevant parameter (https://www.merriam-webster.com/dictionary/parameter), and which is the unit of measurement, for the 'scoreboard' of this hypothetical commonality of reproduction across all organisms?

If the answer is simply the rate of reproduction of individuals, then it should be the case that microbes dominate all ecosystems. This is because the smaller the individual body, the more rapid the turnover from one individual/generation to another.

Microbes will, everywhere and always, tend to outreproduce macrobes.

What this would look like is bacterial plaques covering the land to the exclusion of vegetation, and plankton occupying the seas to the exclusion of even fishes.

If life were resolved to a reproductive contest, large trees - let alone whole forests - would surely not exist? And, most particularly, the human species - which reproduces exceptionally slowly even among primates - would be uncompetitive?

It is difficult to theorise on cause and effect in Biology without knowing the ultimate effect that life is after.

So, what could this ultimate effect be?

Posted on May 09, 2023 10:01 PM by milewski milewski

Comments

Interesting post, I'm no expert but here's my 2 cents for what it's worth.

I think that it's not rate of reproduction that organisms tend to maximize, but rather achieving a sustainable likelihood of reproduction. Yes, some organisms like single-celled bacteria or viruses do benefit from reproducing quickly. These are probably the most prolific species on the planet. But they don't take over completely, as their likelihood of reproduction can be shattered quickly with a sudden lack of resources, space, a bacteriophage, a vaccine etc. - a problem caused by what benefits them initially - rate of reproduction. They have limited capabilities to negotiate these problems. And so, they die-off in huge numbers, but the remainders build-up the new species and the cycle continues...

There are benefits of biological complexity, which can often "keep at bay" the fast rates of simpler organisms. An albatross breeding on a sub-Antarctic cliff, for instance, is one of the slowest reproducing birds in the world. Yet they exist. Why? Because their likelihood (probability) of reproducing is sustainable, like the bacteria. This assumes an unaltered environment (hence why they are now endangered, but off-topic). Any complex organism has evolved probably because they can sustain a high likelihood of reproduction throughout. Maybe they haven't "lost" to the absolute flat-out rates of bacteria reproduction because they have evolved adaptations away from rate of reproduction and towards utilizing new resources, multicellularity, methods of avoiding infection etc.

Finally, individual organisms that do not reproduce, for whatever reason, are more than likely to exist. Then they die. And so, if there is a genetic basis for this avoidance or inability to not reproduce, it will not be inherited. Hence why, generally, every organism tries to reproduce.

Posted by noahfenwick about 1 year ago

Thanks Antoni,

I'll have a read.

Posted by noahfenwick about 1 year ago

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