Evolution of Brain Size

The metabolic cost of neural information

Laughlin et al. 1998.

This paper show that transmitting neural information is costly. Moreover, the energy can change with the type of information is been transmitted, and also with the adaptations of the organs involve in collecting information from the environment (e, g., vision). I like the way they integrate different fields, physics, chemistry and anatomy, to explore the cost of information transmitted. I have few questions, How can we put this in to evolutionary context? and where selection is acting? During the developing stage or as an adult?. I just have a few ideas about this. If storing, gathering and analyzing information is very expensive one should expect that organism that are not energetically constraint will have higher brain capacity. But this is hard to accomplish in the long term as resources has been changing throughout time which means that energy availability also had change. So been able to manipulated the constancy of this resources has been the key to maintained the energy expenditure in human brain?. On the other hand if selection is acting during the embryonic develop one may expect that organism that live in constant and energy rich environments have been able to 1) put more resource into embryo formation or 2) delay the embryonic developing to allow the formation of more complex brain networks, these are not mutually exclusive mechanism.