In this kind of population, the make up of the population's gene pool will remain virtually the same as long as these conditions hold. In this kind of situation, no evolution can take place, all thing will remain the same. For evolution to occur, competition must exist.
They do not have a distinct head and thorax but a fused version of the two called a cephalothorax. That's one of the major differences between insects and crustaceans, both being subgroups of arthropods.
The answer seems like water. We're made up of 70% of water & many of the chemical reactions necessary for live need water as a reactant or a solvent.
Hope that helps!
Amino acids form ionic bonds called 'hydrogen bonds' with hydrogens attachjed to other amino acids. This happens to hold your DNA double helix together :)
