Income – Expenses = Life
Summary: We don’t think of it this way, but just like in modern businesses, animals and organisms in nature make investments and get returns. They don’t get these returns in money, but in calories. Over time, if their invested energy continually pays back significantly more than the energy they invest
to obtain it, they live. If not, they starve. Organisms which have strategies, locations, or skills that allow them to obtain high caloric return for each of their own calories expended have many advantages. The excess calories from a cheetah chasing and killing a large antelope with a single burst of speed might last it a week, providing vital protein and nutrients for cellular metabolism, maintenance and repair, bodily growth, or some extra to go on a cat prowl in search of a mate. 94 Animals that expend a great deal of energy and only get slightly more in return from the calories in their prey don’t survive too long, as others of their kind have spare energy to outcompete them or make it through droughts or tough times. In fact, in the struggle for existence in our planet’s history, one of the most important drivers of evolution has been the ratio of energy returned on energy invested. 95 Would a cheetah have a higher ER/EI if it chased and caught a gazelle, a rabbit, or a mouse? And what would that suggest for its survival and opportunities? It turns out that just like with a salary, there is a difference between the Gross and the Net payc heck. After the taxes are paid, what’s available to spend is less, sometimes considerably so. Nature works the same way - each organism is subject to an energy tax measured in calories spent. The ER/EI is a very big deal. TaaL: (Well if you’re asking me, i f there were enough small critters that a cheetah could grab them without moving or running much, mice might make more sense. Those horns look sharp. And in fact, I’ve seen arctic wolves switch from large prey to mice when there are mice-loads of mice around, because the risk/benefit calculation swings to favor that as an
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