Blood, Bulbs, and Bunodonts: On Evolutionary Ecology and the Diets ofArdipithecus,Australopithecus, and EarlyHomo

Abstract

Beginning with Darwin, some have argued that predation on other vertebrates dates to the earliest stages of hominid evolution, and can explain many uniquely human anatomical and behavioral characters. Other recent workers have focused instead on scavenging, or particular plant foods. Foraging theory suggests that inclusion of any food is influenced by its profitability and distribution within the consumer’s habitat. The morphology and likely cognitive abilities of Ardipithecus, Australopithecus, and early Homo suggest that while hunting and scavenging occurred, their profitability generally would have been considerably lower than in extant primates and/or modern human hunter-gatherers. On the other hand, early hominid diet modelers should not focus solely on plant foods, as this overlooks standard functional interpretations of the early hominid dentition, their remarkable demographic success, and the wide range of available food types within their likely day ranges. Any dietary model focusing too narrowly on any one food type or foraging strategy must be viewed with caution. We argue that early hominid diet can best be elucidated by consideration of their entire habitat-specific resource base, and by quantifying the potential profitability and abundance of likely available foods.

A neurochemical hypothesis for the origin of hominids

“…Ardipithecus was uniquely equipped with a relatively primitive (late Miocene-like) postcanine dentition combined with a substantially reduced sectorial canine complex (14,85). Essentially an omnivore, it is inferred to have relied significantly on forest floor foods requiring a search-intensive collection strategy (14,(86)(87)(88).…”

A complex adaptive system may be essential for cumulative modifications in tool design

“…60 billion neurons would have needed to spend nearly 9 hrs per day feeding, which was probably impossible on a chimpanzee-like diet of mostly collected food. H. erectus had a richer diet than previous hominins, with softer foods (Sayers & Lovejoy, 2014). Craniodental chartacteristics (e.g.…”

“…Most diets of modern hunter-gatherer societies appear to consist of 65% plant foods, which yields an estimate of 35% meat in pre-agricultural hominins (Walker et al, 2002;Luca et al, 2010). However, some authors propose that the diet of H. erectus contained less meat than the diet of modern humans living in similar habitats, and that H. erectus was characterised by great diet flexibility according to habitat differences (Sayers & Lovejoy, 2014).…”

Alternative Ernährungsformen

“…B. mittels Isotopenverfahren) erlauben es allenfalls, Tendenzen im Essverhalten unserer prähistorischen Vorfahren auszuma-Tab. 1 Angaben zu den lebensmittel-und nährstoffbezogenen Charakteristika "der" paläolithischen Ernährung im Verlauf der letzten 30 Jahre (zusammengestellt nach Daten von [11,38,40,41] chen [42]. Erschwerend kommt hinzu, dass die etwa 2,6 Mio.…”