Primitive Ladder-of-Life Thinking Has Evolved—Response

Abstract

![Figure][1] CREDIT: LUC VIATOUR/WIKIMEDIA COMMONS Kutschera questions our use of the word “primitive” when referring to jellyfishes as compared with zooplanktivorous fishes. We did not intend to invoke the idea of a “lower rank” in the “ladder-of -life,” an old, yet popular, prejudice ([ 1 ][2]). We limited our use of the word to the context of prey encounter mechanisms. We argued that the jellyfish mechanism—stirring water to increase the chance that prey will collide with their collection surfaces—is less complex than the visual predation by the zooplanktivorous fishes. However, we then showed how the simple mechanism of contact predation is bioenergetically as efficient (i.e., as evolved) as the seemingly more complex visual mechanism. In other words, the main point of our Report could well be used in support of Kutschera's contention. 1. [↵][3] , The Origin of Species (John Murray, London, ed. 6, 1872). [1]: pending:yes [2]: #ref-1 [3]: #xref-ref-1-1 View reference 1 in text