The meaning of life is pretty simple. There are three main rules:
- Eat
- Don't get eaten
- Reproduce
That's basically it. There are also some finer points such as breathing, but the main gist is to steal as much energy as possible without letting anyone else steal yours, in order to live long enough to have children.
You have to keep eating so that you don't die of starvation. For endothermic lifeforms, this means eating occasionally. For exothermic ones (that means you), you really need to do it daily. As Neil deGrasse Tyson said in a presentation at the Beyond Belief convention1, "We have to eat constantly because we're warm blooded. A crocodile'll eat a chicken a month, it's fine."
You have to keep running away from other lifeforms trying to eat you, or defend yourself in some other way. Since we humans invented things like weapons and walls, this is pretty easy to forget, but the natural way of living is to die at a young age by, for example, being eaten by a lion.
Reproduction is where the magic happens. One or two lifeforms combine to make a new one. The parents are eventually discarded so that the child can take their place, and the whole cycle continues. In the process, the child has some random new piece of genetic code to try out. With any luck, it might give this new lifeform some advantage that improves the chances of her or his reproduction. If she's unfortunate, it'll give her a disadvantage that'll get her eaten before she can reproduce. More likely, it won't make any noticeable difference. In this manner, all lifeforms are very slowly refined.
To make the game interesting, any lifeform can have its energy stolen by being eaten by another lifeform. If your random mutations happen to have given you the inclination and the body parts necessary to steal someone else's energy in a new and interesting way, it's considered fair game. Nature is ruthless, and nothing will get you disqualified from the game on grounds of cheating.
As you might expect, this has resulted in some pretty nasty survival techniques that would give horror writers a run for their money. For example, there's a genus of wasp which injects her offspring into a caterpillar. The larvae then eat the caterpillar from the inside out, and as if that's not gruesome enough, the behaviour of the caterpillar is somehow modified to make it defend them2.
Wasps aren't alone in their ability to alter the behaviour of others to suit their own agenda. Another example is the Lancet liver fluke, which has developed an astonishingly elaborate life cycle in which it gets eaten by a snail, then an ant, which it gets to climb up to the top of a blade of grass in order to be eaten by a cow or sheep.
In case this seems too depressing, or even downright scary, there are plenty of examples of symbiotic, cooperative survival techniques. For example, plants reproduce via bees, giving them nectar, in exchange for which the bees carry their pollen from one plant to another. Crocodiles and hippos let birds clean their teeth. They forgo the temptation to eat the bird because it's more useful to have clean teeth.
So life itself is about eating and reproducing, and a side effect of life is the refinement of all lifeforms to make them better suited to their current environments, otherwise known as evolution by means of natural selection.
This is what life is about. It needn't be what we're about, now that we're clever and knowledgeable enough to have developed a society, a culture. We now have the choice of making up our own purpose, our own personal reason for getting out of bed in the morning. That's what I prefer to do. We're so privileged to live in a society, that it's an insult not to take advantage of our wonderful situation. But don't kid yourself: it's not natural. It's better than natural.
If you're looking for a clever, thought provoking point to being alive, you're going to be sorely disappointed or forever searching for something that isn't there. It all boils down to food and sex.
References
- YouTube: revtyson: What does Neil Tyson think about Intelligent Design?
- New Scientist: Zombie caterpillars controlled by voodoo wasps