(FWIW, I’d be inclined to exclude nematodes, though. Including them feels like a mugging to me and possibly dominated by panpsychism.)
I included nematodes because they are still animals, and think seriously attempting to estimate (as opposed to guessing as I did) their moral weight would be quite valuable. From my results, the scale of welfare of an animal group tends to increase as the moral weight decreases (assuming the same intensity of the mean experience as a fraction of that of the worst possible experience). If the moral weight of nematodes turned out to be so small that the scale of their welfare was much smaller than that of wild arthropods, we would have some evidence, although very weak one, that the scale of the welfare of populations of beings less sophisticaded than nematodes[1] would also be smaller.
I suppose there is very little data relevant to assessing the moral weight of nematodes. However, it still seems worth for e.g. Rethink Priorities to do a very shallow analysis.
I included nematodes because they are still animals, and think seriously attempting to estimate (as opposed to guessing as I did) their moral weight would be quite valuable. From my results, the scale of welfare of an animal group tends to increase as the moral weight decreases (assuming the same intensity of the mean experience as a fraction of that of the worst possible experience). If the moral weight of nematodes turned out to be so small that the scale of their welfare was much smaller than that of wild arthropods, we would have some evidence, although very weak one, that the scale of the welfare of populations of beings less sophisticaded than nematodes[1] would also be smaller.
I suppose there is very little data relevant to assessing the moral weight of nematodes. However, it still seems worth for e.g. Rethink Priorities to do a very shallow analysis.
From Table S1 of Bar-On 2017, bacteria (10^30), fungi (10^27), archaea (10^29), protists (10^27), and viruses (10^31).