Which of the following examples shows how scientists continue to investigate darwin’s idea that species change over time by natural selection?

a. ornithologists study the wing shape and flight patterns of birds.
b. archaeologists uncover, catalog, and compare fossils of marine life.
c. microbiologists examine the reproduction rates of bacteria.
d. ecologists obtain samples of tree trunks to determine the trees’ ages.

Jasmine, at 33 months of age, is able to engage in some self-care behaviors but still has trouble with tasks such as putting on socks. a few months later, she accomplishes this same task relatively easily. the change in abilities is most likely due to

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased

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.