2. "the present is the key to the past." this statement rephrases the (1 point)
principle of cross-cutting relationships
law of gravity
principle of uniformitarianism
principle of original horizontality
3. why would a worm stand a poor chance of being fossilized? (1 point)
worms did not exist in the geologic past.
worms have been rare during the geologic past.
worms have no hard parts.
all of the above

What is the identity of the planets?

Female luna moths (actias luna) attract males by emitting chemical signals that spread through the air. a male hundreds of meters away can detect these molecules and fly toward their source. the sensory organs responsible for this behavior are the comblike antennae visible in the photograph shown here. each filament of an antenna is equipped with thousands of receptor cells that detect the sex attractant. based on what you learned in this chapter, propose a hypothesis to account for the ability of the male moth to detect a specific molecule in the presence of many other molecules in the air. what predictions does your hypothesis make? design an experiment to test one of these predictions.

In "the pig," what is the main effect that the piglet initially has on kibuka?