The retina uses visual fields to recognize objects in the environment.
a. true
b. false; visual pigments are most important
c. false; contrast is the most important feature.
d. false; absolute light intensity is more important
e. false; ganglion cells are all that’s needed

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.