I don't know exactly, but the tread pattern isn't really what matters. Whats more important in terms of tire longevity is the rubber compound, thickness, and tire construction. I'm betting the Pasela Tourgaurds (PT) are similar in those respects. I've used PTs and they are long lasting tires and can withstand a lot of skidding. I've never used Soma tires, so I don't know how they would compare. But I'm betting the PTs are a better bargain, even if they are not exactly the same as Soma everwears.

Whatever you buy, do not ever buy Continental ultrasport tires. The low price and decent looks will tempt you, but those tires are cursed by Satan, and will puncture just by looking at them.