According to ‘science’, life is nothing but a process through which (genetic) information is passed, with small alterations, from one generation to another and during which the environment is, however minutely, changed by whatever the living organisms do during their lifespans.
‘Individually’ – organism by organism, life takes place inside a ‘membrane’. Which you might call it ‘skin’, if you like.
That membrane separates the ‘inside’ – the living organism, from the ‘outside’ – otherwise known as the ‘environment’.
Each individual organism continues to be alive for as long as the membrane manages to keep the inside in, the outside out AND to properly regulate the exchanges between the inside and the outside.
This being the moment when we need to remember that each living organism needs to eat, to drink, to breathe and to excrete. Meaning that it needs a more or less continuous flow of certain substances from the outside and to periodically clean itself. And the moment to understand that each organism continuously changes its environment. By incorporating some of it while feeding/breathing and by ‘polluting’ it when ‘throwing out’ the by-products of its metabolism.
For all the activity above to take place, each individual organism needs to follow some ‘rules’. It’s ‘membrane’ needs to ‘know’ which substances to allow in and which to keep out. Which substances to throw out and which to keep it.
To perform all these duties, the membrane itself needs to be organized in a certain manner. For all to happen as it should, the ‘interior’ has to be organized in a certain – and specific, manner.
On the other hand, for any (set of) rule(s) to make sense, it has to be congruent to the situation it ‘attempts’ to manage. For instance, the rule about what substances are to be ‘allowed in’ has to be adapted both to the specific needs of the organism following it AND to what substances are available in the particular environment in which that organism attempts to survive/thrive.
Since the environment in which the living process attempts to take place is subjected to continuous change – both as a consequence of organisms living in it and as happenstance happening, the ‘rules of life’ cannot be ‘set in stone’.
For life to continue in a consistent manner, it has to preserve its rules while for life to survive in an ever-changing environment it has to adapt its rules to fit the changes in the environment.
This being where evolution takes charge.
That’s why the life we’re familiar with, ours, is comprised of successive generations of many individual organisms which somehow pass genetic information (rules of life) from one another. The fundamental ‘trick’ which makes everything possible being that during the ‘passing’ process the genetic information is slightly altered.
Sometimes with beneficial results – those individuals thrive and, eventually, new species appear. Other times, the results are tragic. The individuals which receive bad – read unfit, rules of life do not survive.
Equally tragic is the fate of those species, otherwise ‘successful’ until that moment, which, at some point, are confronted by so momentous changes in their environment that they are no longer able to adapt. Dinosaurs are the first examples which come to my mind but the list is so long that we’ll never learn about all of them.
A pessimist might conclude that life is all about species and that individuals are expandable.
Au contraire, mon cher ami. Since there’s no way in hell – or in heaven, for anybody to know which individual organism has that particular piece of information which will enable their successors to survive the next alteration in the environment it would be rather dense to consider any individual as being expandable. In fact, it was the ‘individualization’ of the living process that made possible the evolutionary process.
Life is about both individuals and species, simultaneously and with equal importance.