25/05/2012 [DMFA #1311] - Simple tasks.

[llearch n'n'daCorna]

It's possible, psilorder, but there's a _lot_ of structure behind the mechanics of how the shoulder works. If you don't have that support (and the ribcage really isn't enough, for all that we think of it like a cage, it's more like a paper-mache balloon in comparison) then while you can have an arm, you don't get to lift anything heavier than, say, a beach towel or so, without it popping out of the joint.

A dry beach towel.

Just think about that for a minute, there, and you'll see why multiple arms didn't evolve here. It's very unlikely to happen anywhere, because single pairs of arms is pretty unlikely as well, but much easier, evolutionarily speaking, to get out in a suitably numerous fashion...

[MT Hazard]

I think that extra limbs lower down the body could be usable,  a second set of set of 'shoulders' could support the extra limbs rather than attaching them to the rib cage.

If anyone wants to have a intelligent species (like an alien race) with multiple arms it should be that other less intelligent animals from their world have them as well, think having both four armed monkeys and four armed humans.

I have been considering the idea of a species with a two sets of arms dedicated to different tasks. The species I designed had a total of 9 limbs (tail included) and their lower arms are significantly different in structure that the upper arms.

Don't know how much of that makes sense, sorry.