Imagine that a population of well-armored modern Indo-Pacific snail species was magically transported to Triassic seas, where suitable food and substrate were available. Would natural selection favor increase, decrease, or maintenance of the snail’s armor in its new environment?. Earth & Marine Sciences

  1. Main page
  2. Library
  3. Earth & Marine Sciences
  4. Imagine that a population of well-armored modern Indo-Pacific snail species was magically transported to Triassic seas, where suitable food and substrate were available. Would natural selection favor increase, decrease, or maintenance of the snail’s armor in its new environment?

Modern Indo-Pacific snails are much better armored than were their ancestors of the Triassic (~250 mya). Modern snails would face few predators and would easily be able to prey on the Triassic fauna. The defense features of modern snails (thickened shells, spikes etc.) all come at an energetic cost. If the benefits were few (i.e., the features were not necessary to defend them from Triassic predators), then the balance of costs and benefits for  maintaining these structures would shift, and natural selection would favor individuals with decreased armor.

Materials by theme:
Formation of primary social relationships Lections
The family: global variety Lections
Affective Maximization Lections
The Psychology of Emotions Lections
Social Psychology - Doing Social Psychology Research Lections
Ecologists are Scientists Lections
New imperialism Lections
Plans and Planning Tools Lections
Origins of Food Predictions / Origins of Complexity Lections
Evolution, Genetics and Human Biological Variation Lections