saltation
/salˈteɪʃ(ə)n
/ /sɔːlˈteɪʃ(ə)n/ /sɒlˈteɪʃ(ə)n/noun [mass noun]
1 Biology Abrupt evolutionary change; sudden large-scale mutation: new genetic characters appear suddenly by saltation [count noun]: a new concept of evolution by saltations or sudden transitions...
- He gave examples of new races formed in sudden jumps or saltations to illustrate that ‘the evolution of organisms may… be a much more rapid process than Darwin believes.’
- In a phylogenetic dendrogram, branches and twigs here and there show saltations into a new grade.
- But accepting the data at face value raises the interesting possibility that hierarchy may be quite labile, that hierarchical saltations may be relatively easy in evolution.
2 Geology The transport of hard particles over an uneven surface in a turbulent flow of air or water: the distance travelled by each grain during saltation...
- Eroded sediment can be transported by creep, saltation, or suspension, and where much fine soil or sediment is present, dust clouds can result.
- Although the dunes near Parker seem to be an extension of this same sandflow path, Muhs says that saltation couldn't carry grains of sand across the Colorado River.
- This process, in which sand grains bounce downwind, is called saltation.
3 archaic The action of leaping or dancing.In addition to the dorso-ventral flexion seen during saltation, the sacroiliac joint often allows varying degrees of lateral movement....
- These actions are important in the effective use of the hindlimbs during terrestrial saltation and swimming.
Derivatives
saltatory
- The myelin acts as a layer of high electrical resistance and low capacitance, facilitating the rapid saltatory conduction of electrical impulses from node to node for long distances along axons that may be up to 1 m in length.
- The saltatory nature of this type of flight results in extreme linear and angular displacements of the bird's body; however, birds isolate their heads from these accelerations with cervical reflexes.
- The species possesses paired, elongate lateral spines that function in saltatory sweeping motions in response to sheer disturbances by predators.
Origin
Early 17th century (in sense 3): from Latin saltatio(n-), from saltare 'to dance', frequentative of salire 'to leap'.