Mammals, like humans and apes, have five digits on their fore and hind limbs. modern horses have one. how might you reconstruct the ancestral state of mammal toe number? investigate the number of toes on all extant horses and apes
(a) either b or c investigate the number of toes for other mammals and use parsimony to deduce the ancestral state
(b) investigate the number of toes for an outgroup that is closely related to mammals, for example reptiles or amphibians
(c) all of the above

Astudent sees several ants walking up a wall following the exact same trail that an ant took earlier. she wants to apply the scientific method to determine how the ants detected the trail. which of these steps would come first in her application of the scientific method? perform an experiment by cleaning the scent away from part of the trail. draw a conclusion that the ants follow a scent trail. make a prediction about what the ants will do after she cleans away part of the trail. hypothesize that the ants are following a scent trail that the first ant left.

Animals have a variety of adaptations, including trachea and gills, which allow this key process to occur. which provides the molecules necessary for cellular respiration and efficient atp synthesis?

Which process takes place last in the human being which process takes place last in the development of a human being