Food (SDS RM3 E – expanded diet, Witham, Essex, UK) and water were available ad libitum.
Mice were maintained on a mixed C57BL/6×129S6/SvEv background and fed a standard diet (RM1 expanded diet, Special Diet Services Ltd ,Witham, UK).
However, Daniels (2009) argues that expanding diet breadth when high-ranked resources are stressed is an optimal foraging strategy that would not necessarily indicate active management.
This suggests some cost associated with and expanded nitrogen diet, and raises questions about why plants bother to capture amino acids from soil.
Out of 19 butterfly species examined for response across habitats, five expanded their diet but six contracted their diet with urbanization.
By the time commercial whaling was halted, there were virtually no great whales left for killer whales to eat, and so they expanded their diet first to seals then to sea lions and finally to sea otters.
However, many epigaeic (hunting aboveground) and some hypogaeic (underground) army ant species have secondarily expanded their diet breadth to include other invertebrates and even small vertebrates [ 11, 12].
Since the launch of Diet Coke in the early 1980s, we have substantially expanded the diet beverage category in the U.S., today offering more than 180 low- or no-calorie beverages.
While California's acorn eaters suffered, peoples in the Southwestern deserts expanded their diet to include new edible plants.
That suggests that our ancestors expanded their diet 1.95 million years ago, paving the way for the expansion of their brains and, perhaps, the reduction in size of their teeth and jaws something also seen in H. erectus because these foods are relatively easy to chew, even raw.
Then a neighbor hired him to be in a Crest commercial, and the residuals ("I didn't even know what residuals were," he said) expanded his diet a bit.
