Can natural selection explain how the first single-celled organism evolved into a multi-celled organism?
Not necessarily the concept of natural selection, but I believe evolution states that organisms randomly mutate. A single-celled organism randomly genetically mutated so that it had the ability to undergo some type of division or mitosis or many mutations over time led an organism to gain this ability or the ability to sustain more than one cell. This gave it much better chances for survival so it created offspring more virulently and the trait survived and spread.
Single-celled organisms are much less motile than more complicated organisms and are heavily dependent on stuff such as food sloshing over to them. Also, their primary survival tactic is to simply reproduce as quickly as possible. They aren’t able to take advantage of some natural resources or self-defense techniques, such as physically fighting off a predator or foraging for food. Also, their simplicity precludes the possibility of developing anything more complicated than basic cell systems, such as uptake of materials to generate a bit of energy and dump a bit of waste. With that said though, this is not to say that they’re evolutionarily inferior to us multicellular beings. They are WAAAAY more of them than there are of us, and they’ll still be here when we’re long gone. It is simply that nature gave an opportunity for multicellular characters to flourish for now, but this is a comparatively recent phenomenon relative to how long the single-celled guys have been here.
