Table 2.

The output of the targeting process displays the “maximal pairings”, trait differences for each pair (e.g., log ECV brain residuals), and the score for each pairing

New species to be studied	Already-studied species	Log ECV difference	Score
Microcebus murinus	Propithecus verreauxi	1.107	0.536
Miopithecus talapoin	Gorilla gorilla	0.963	0.466
Callithrix jacchus	Cebus apella	0.878	0.425
Mandrillus sphinx	Macaca fascicularis	0.503	0.244
Daubentonia madagascariensis	Ateles geoffroyi	0.330	0.160
Hapalemur griseus	Varecia variegata	0.300	0.145
Eulemur rubriventer	Eulemur macaco	0.132	0.064
Eulemur fulvus	Eulemur mongoz	0.086	0.042

The score is a measure of each pair’s strength to test the target hypothesis based on phylogenetic relatedness and ECV variation. The species pairings are listed in order of decreasing strength to test the target hypothesis, providing a guide for which “new species” should be the highest priorities for future testing. The targeting process also allows researchers to customize species pairings using simple user-defined variables. The pairings in this table were generated using the criteria (1) there were extant data on one species in the pair and (2) that the “new species” to be studied was available for cognitive testing. When targeting species for cognitive studies, one can generate additional criteria to assure that each pair provides a good comparison using the same behavioral task. For example, a user could require that both species exhibit the same activity pattern (diurnal/nocturnal), which would avoid the pairing of species such as the aye–aye (Daubentonia) and spider monkey (Ateles)

ECV endocranial volume