1	Proximate Explanation		_____	two species that are more closely related to each other than any other species
2	Ultimate Explanation		_____	a trait found in the common ancestor of two or more specie; also known as a plesiomorphic trait
3	Observational Research		_____	operant chamber that is used to study animal behavior
4	Experimental Research		_____	method of studying animals by comparing traits between species; seeks to understand the evolution of behavioral traits
5	Control Group		_____	learning by pairing an instinctual stimulus-response relationship with an unrelated stimulus; also known as Pavlovian conditioning
6	Comparative Research		_____	traits that are similar due to shared common ancestry
7	Ancestral Trait		_____	learning by association of a behavior with its consequence; also known as instrumental conditioning or trial-and-error learning
8	Derived Trait		_____	the idea that the simplest psychological process possible should be used to interpret animal behaviors
9	Phylogeny		_____	hypothesized evolutionary ancestor-descendent relationships among different species
10	Sister Species		_____	a stimulus that initiates a FAP
11	Clades		_____	method of studying animals by observing and recording their behaviors; does not involve the manipulation of environment or animal
12	Homologies		_____	explanation that focuses on understanding the immediate causes of behavior
13	Outgroup		_____	explanation that focuses on understanding the evolutionary reasoning for behavior
14	Synapomorphies		_____	a trait found in an organism that was not present in its common ancestor; also known as an apomorphic trait
15	Parsimony		_____	groups of organisms that are all descended from a common ancestor
16	Morgan's Cannon		_____	rapid observational learning in young animals
17	Classical Conditioning		_____	using technology in place of animals to study animal behavior
18	Operant Conditioning		_____	branch of math that deals with probability
19	Skinner Box		_____	the group in an experiment that is not manipulated; exists to serve as a comparison to the manipulated groups
20	Imprinting		_____	the idea that simplicity is more probable in nature
21	Fixed Action Patterns (FAP)		_____	violation of ethical behavior in science
22	Releaser Stimulus		_____	improving procedures to minimize pain and suffering of animals during research
23	Scientific Misconduct		_____	method of studying animals by manipulating a variable to see how it affects an animal's behavior
24	Replacement		_____	species that are distantly related to each other
25	Reduction		_____	instinctual behaviors that are invariant, unlearned, and always brought to completion once initiated
26	Refinement		_____	limiting the number of animals used to study animal behavior
27	Statistics		_____	shared derived traits