title: A fish is not a fish: patterns in fatty acid composition of aquatic food may have had implications for hominin evolution.
abstract: From c. 2 Ma (millions of years ago) onwards, hominin brain size and cognition increased in an unprecedented fashion. The exploitation of high-quality food resources, notably from aquatic ecosystems, may have been a facilitator or driver of this phenomenon. The aim of this study is to contribute to the ongoing debate on the possible role of aquatic resources in hominin evolution by providing a more detailed nutritional context. So far, the debate has focused on the relative importance of terrestrial versus aquatic resources while no distinction has been made between different types of aquatic resources. Here we show that Indian Ocean reef fish and eastern African lake fish yield on average similarly high amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA). Hence a shift from exploiting tropical marine to freshwater ecosystems (or vice versa) would entail no material difference in dietary long-chain polyunsaturated fatty acid (LC-PUFA) availability. However, a shift to marine ecosystems would likely mean a major increase in access to brain-selective micronutrients such as iodine. Fatty fish from marine temperate/cold waters yield twice as much DHA and four times as much EPA as tropical fish, demonstrating that a latitudinal shift in exploitation of African coastal ecosystems could constitute a significant difference in LC-PUFA availability with possible implications for brain development and functioning. We conclude that exploitation of aquatic food resources could have facilitated the initial moderate hominin brain increase as observed in fossils dated to c. 2 Ma, but not the exceptional brain increase in later stages of hominin evolution. We propose that the significant expansion in hominin brain size and cognition later on may have been aided by strong directional selecting forces such as runaway sexual selection of intelligence, and nutritionally supported by exploitation of high-quality food resources in stable and productive aquatic ecosystems.
authors: Faculty of Archaeology, Leiden University, P.O. Box 9515, 2300 RA Leiden, The Netherlands. Electronic address: j.c.a.joordens@arch.leidenuniv.nl.
authors: Josephine C A
authors: JC
authors: Joordens
authors: Department of Cardiology, Onze Lieve Vrouwe Gasthuis, Oosterpark 9, 1091 AC Amsterdam, The Netherlands; Laboratory Medicine, University Medical Center Groningen (UMCG), Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
authors: Remko S
authors: RS
authors: Kuipers
authors: Institute of Biology Leiden, Leiden University, P.O. Box 9505, 2300 RA Leiden, The Netherlands; Koeman en Bijkerk bv, Ecological Research and Consultancy, P.O. Box 111, 9750 AC Haren, The Netherlands.
authors: Jan H
authors: JH
authors: Wanink
authors: Laboratory Medicine, University Medical Center Groningen (UMCG), Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
authors: Frits A J
authors: FA
authors: Muskiet
mesh_terms: D000818:Animals; D000885:Anthropology, Physical; D005075:Biological Evolution; D004032:Diet; D005227:Fatty Acids / Q000032:analysis*; D005399:Fishes; D005580:Fossils; D015186:Hominidae / Q000502:physiology*; D006801:Humans; D007630:Kenya; D017747:Seafood / Q000032:analysis*
chemical_list: D005227:Fatty Acids
keywords: AA; Brain growth; DHA; Diet; EPA; LC-PUFA