3 ms·
3/4 of the time period of life on earth was single-celled organisms.... but what people might miss when they look at this was that it was always an interactive
by photochemsyn 3y ago
3/4 of the time period of life on earth was single-celled organisms.... but what people might miss when they look at this was that it was always an interactive system. What we call 'life' arose on top of chemical and physical processes that were only enabled by the flows of energy from (1) our young and energetic Sun and (2) our highly radioactive earth core. From the very point where the system started cooling down enough to allow carbon-carbon bonds to form the context of an aqueous environment, life was already there, the potentiality at least.
Of course, by this measure of our own history, we should expect ~3/4 of the Earth-like planets we discover to have nothing more advanced than single-celled life.
Now, the question of how single-celled life could have given rise to multicellular life and the origination of chromosomes, etc. is a whole other question, see slime molds.
- enkid 3y agoMulticellularity evolved independently many times (25 according to Wikipedia). It first potentially to evolved 3 billion years ago.
- WalterBright 3y agoMulti-body organisms have also independently evolved - bees, termites, ants, wasps.
- defrost 3y agoLet's not forget single-body multi organisms ... More than half your body is not human https://www.bbc.com/news/health-43674270 https://www.bbc.com/news/health-43674270
- asplake 3y agoNot sure that this list illustrates that. Not only are these all insects, they are all of the same order, hymenoptera, ie somewhat closely related.
- NoZebra120vClip 3y agoThe organisms referred to by the GP are not insects. They are social colonies chiefly made up of insects as their component parts, but the whole is greater than the sum of parts. Consider fungi, microscopic plants, and even aphids which are farmed, to be parts of these organisms, not to mention the elaborate dwelling structures. These social organisms go far beyond individually embodied insects.
- enkid 3y agoAlso mantis shrimp and naked mole rats. These are all creatures that have evolved a reproducing queen and sterile workers. However, I don't like the definition of calling a colony of such creatures an "organism" because it implies the only purpose of an organism to reproduce. You then end up getting weird edge cases like fig trees and fig wasps being a "single organism." Also, male/female pairs of humans would be a strong angle organism.
- WalterBright 3y ago> it implies the only purpose of an organism to reproduce Isn't that the evolutionary purpose (if there is a purpose at all) of all life?