Read the selection from the section "Vestigial Structures." These are leftovers from an earlier form of the species before it changed. Over time, a species can collect several adaptations that eventually render a particular structure useless, however, this structure does not completely disappear.

Hydrogen and helium are both members of?

If a balloon is taken outside on a very cold day, what will occur?

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.