a million years without sex

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Snarky females may rejoice and wand-waving males despair, but a million years of asexual reproduction appears to be a fact. In an evolutionary world that relies heavily on what might be called vive-la-difference survival rates, stick insects have managed to thrive without the urge to merge. Given the adaptations required over such a long period of time, scientists seem to be flummoxed by the ability of stick insects not to self-destruct.

How can anything remain "the same" and hope to survive?

I imagine the definition of "the same" will have to be nailed down before an answer appears.
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