The Collaborative International Dictionary of English v.0.48:

Saltation \Sal*ta"tion\, n. [L. saltatio: cf. F. saltation.]
   1. A leaping or jumping.
      [1913 Webster]

            Continued his saltation without pause. --Sir W.
                                                  Scott.
      [1913 Webster]

   2. Beating or palpitation; as, the saltation of the great
      artery.
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   3. (Biol.) An abrupt and marked variation in the condition or
      appearance of a species; a sudden modification which may
      give rise to new races.
      [1913 Webster]

            We greatly suspect that nature does make
            considerable jumps in the way of variation now and
            then, and that these saltations give rise to some of
            the gaps which appear to exist in the series of
            known forms.                          --Huxley.
      [1913 Webster]

WordNet (r) 3.0 (2006):

saltation
    n 1: (geology) the leaping movement of sand or soil particles as
         they are transported in a fluid medium over an uneven
         surface
    2: (genetics) a mutation that drastically changes the phenotype
       of an organism or species
    3: an abrupt transition; "a successful leap from college to the
       major leagues" [syn: leap, jump, saltation]
    4: taking a series of rhythmical steps (and movements) in time
       to music [syn: dancing, dance, terpsichore,
       saltation]
    5: a light, self-propelled movement upwards or forwards [syn:
       leap, leaping, spring, saltation, bound, bounce]