Can toads are large, nonnative, poisonous toads in australia. after cane toads entered australia, scientists observed that the average head size in a population of toad- eating snakes was getting smaller. snakes with smaller heads are not able to eat the large cane toads. what is this an example of? a. directional selection b. biodiversity c. speciation d. disruptive selection

This an example of directional selection

Directional selection is a type of natural selection whereby the observable traits (phenotype) such as skin color of a population evolves toward one end of a trait rather than the mean phenotype, or the opposite extreme phenotype. Directional selection usually occurs in environments that have changed over periods of time. Directional selection is caused by certain factors such as climate, weather changes, or food availability.

a and b

x would be the most and the least would be y because there are more fruit   and seeds than flock z has insects