There was life on earth for a couple of billion years before the first predators, everything we've seen on planets in ED is immobile, it's hard to hunt if you can't move. Where there is predation that provides an evolutionary pressure which can alter the shape of the prey but if there are no predators...
Are you referring to multicellular or unicellular life forms? Because both have to respond to predation. And both eventually adapt by evolving mobility. But the life forms in Elite shouldn't even be multicellular. They need an ecosystem with predators in order to achieve that.
But that's Ok with me, we need something to find and this will work until we can land on planetary biomes.