Brain structure evolution in a basal vertebrate clade: evidence from phylogenetic comparative analysis of cichlid fishes

Table 4 Maximum likelihood estimates of the evolutionary parameters

Brain structure	Brownian	Lambda			Alpha
	Ln Likelihood	λ	Ln Likelihood	P	α	Ln Likelihood	P
Brain weight	5.69	0.65	7.29	0.07	1.54	7.68	0.05
Olfactory bulbs	-0.36	0.45	4.01	0.003	2.61	3.62	0.01
Telencephalon	2.12	0.80	2.53	0.60	1.57	3.74	0.07
Optic tecta	5.45	0.92	5.53	0.69	1.22	6.56	0.14
Cerebellum	-0.93	0.71	-0.40	0.30	1.42	0.56	0.08
Dorsal medulla	-1.45	0.96	-1.42	0.81	0.40	-1.26	0.53
Hypothalamus	4.79	0.51	6.83	0.04	2.02	7.32	0.02

Maximum likelihood estimators for the λ and α statistics of whole brain weight and six major brain structures. The Ln likelihoods of the null Brownian motion model and those of the two alternative models are shown for comparison. P values for the λ and α parameters were determined from likelihood ratio tests against a model with constant rates of evolution (unconstrained Brownian motion).

ISSN: 2730-7182