Therapeutic agents from the sea: biodiversity, chemo-evolutionary insight and advances to the end of Darwin's 200th year.

Drugs from the sea? Darwin may not have considered this concept when he was thinking about mechanisms that drove diversification of life on earth. In recognition of his 200th year, and celebration of the publication in 1859 of his "On the origin of species", we review the global status of marine biodiscovery in medicinal fields, with a focus on the South Pacific. Furthermore, in the Darwinian spirit, we touch on putative evolutionary drivers and the chemical ecology of the successful leads. We argue that, for the relatively limited investment in effort to date, the success of marine leads as therapeutics promotes enhanced focus on marine biodiversity as a source of useful medicinal agents. The simple prime argument in support of this is the fact that we can exploit over four billion years of evolution in combinatorial chemistry in marine organisms, directed at relevant and effective biological activity.