>How long can a cell survive without liquid water? Depends on the cell, but it’s not instant death. By definition, a cell is a membrane with some water inside

>How long can a cell survive without liquid water? Depends on the cell, but it’s not instant death. By definition, a cell is a membrane with some water inside it. Sure, move that cell to totally dry conditions and most will die. But not all, by any means. Bacterial endospores last millenia without water. Tardigrades can do years. This isn’t quite the gotcha you think it is. The metal use for multiple catalytic steps is distinct. The paper isn’t wrong about that at all. Trying to prove the closed loop metabolism of modern life is secretly open loop isn’t going to work because it isn’t open like that. An organism can survive without constant contact with any of its components. Sometimes not for very long, but nothing alive today is as dependent on something external as these proto cells were on reduced metal.