Are you reading Lloyd's "natural selection and mutation" to mean not "these two
natural processes" but rather something like "these two natural processes only
where they are jointly and simultaneously operative"? I suspect Lloyd meant
the former, whereas your reading of him seems to be the latter.
In any event, if one wants to be extremely pedantic, there are plenty of
biological differences that are due to neither of these (e.g., a limb being
damaged by a falling rock), but I doubt Lloyd meant to cover those in his use
of "all".
--John