EPOW - Ecology Picture of the Week

Of Kangaroos, French Cooking, 
and Jumping Spiders

Jumping Spider, Family Salticidae
Mindo, Ecuador

Explanation:  What do kangaroos, French cooking, and jumping spiders have in common?  

This is a lesson in convergent adaptations and the evolution of language.  Call it "ecoetymology" (my coinage).

The hero of this week's image is a diminutive jumping spider, no larger than my pinky fingernail, that I photographed in the mid-elevation tropics of the western Andes Mountains in Mindo, Ecuador.  

Jumping spiders are amazing and frenetic little creatures.  With diverse and great eyesight, they detect motion as potential predators, and with a flick of their multiple legs suddenly vanish before your own eyes in a quick leap.  
 

Note the unique eye structure of jumping spiders, by which
they can detect near and far motion and detail.  

How animals move is technically called locomotion, and locomotion by jumping is called saltation.  

So what other animals locomote by saltation?  Well, members of the family Macropodidae do ... these are the kangaroos, wallabies, euros, pademelons, and other species, that evolved uniquely in Australia to hop on hind legs.  It is quite an interesting case of convergent evolution that such dissimilar life forms -- spiders and mammals -- with such different body forms and massive differences in body mass and size, have developed the ability to hop.  The difference is that jumping spiders jump with all 8 legs.

Wait, there's more.  Jumping spiders belong to the family Salticidae, derived from saltation.  Makes sense. 

Further, the word saltation itself dates back to the 1620s from the Latin saltationem, derived from saltare, meaning to hop or dance.  Saltare also gave rise to saute, the word we now use to refer to tossing food while cooking.  If saute sounds French, it is, dating to the 1813 French sauté, meaning jumped or bounced.  

And here we come full circle, as kangaroos, jumping spiders, and French cooking all involve ... jumping! 
 

More:  Know what else jumps with saltation locomotion?  Sand!  On sand dunes, in the wind, particles of sand skip and bounce with movement technically referred to, indeed, as saltation.  

Fun fact:  if you've ever seen ripples in sand, like at the beach or in the desert, it's a fact that the average distance a grain of sand can bounce (saltate) is the width between the crests of the ripples.  Now you know.