On the origin of skilled forelimb movements

Homologizing behaviour was once considered unreliable, but the application of modern comparative methods has been shown to provide strong evidence of behavioural homologies. Skilled forelimb movements were thought to originat e in the primate lineage but in fact are common among tetrapod taxa and pro bably share a common origin in early tetrapods, Furthermore, skilled moveme nts are likely to have been derived from, and elaborated through, food-hand ling behaviour. In addition, it is now thought: that the role played by the lateral and medial descending pathways of the spinal cord in the execution of skilled forelimb movements could be synergistic, rather than the exclus ive responsibility of an individual pathway.