Monday 28 August 2017

Carnivores And The Valar

"The Valar recognized that humankind had a right to eat just as the other carnivores did..."
-SM Stirling, The Given Sacrifice (New York, 2014), Chapter Fifteen, p. 280.

Human beings are not carnivores but omnivores and can make moral choices about what to eat.

Three views:

we are accountable to deities for what we eat;
we have evolved without divine oversight and can eat what we want;
we are responsible for the conservation of the environment and sometimes acknowledge this responsibility by personifying aspects of the environment.

14 comments:

Sean M. Brooks said...

Kaor, Paul!

While as a Christian I believe all foods are kosher (following Christ's words in Mark 7.14-23, Acts 15, etc.) there are still some things humans should not do, such as killing people for food. That is to go too far and to cast out the perpetrators from human society. Sometimes this was rationalized as a command from a people's gods to sacrifice humans to them, after which the worshipers could eat the bodies. The most notorious example of that, of course, being the Aztecs.

Sean

S.M. Stirling said...

Technically humans are omnivorous, but in ecological terms until the invention of agriculture they were apex predators for a very, very long time -- since long before the emergence of H. sapiens sapiens. Stable bone isotope ratio analysis has shown that both early humans and hominins like Neanderthals got the overwhelming majority of their calories from animals and birds, and there's substantial evidence that this goes back hundreds of thousands of years.

The modern human body plan and overall size emerged with h. erectus about 1.8 million years ago -- the differences between us and them are all above the neck, apart from thinner bones. And that plan makes sense only for a cursorial hunter. The one thing we do better than any other mammal is long-distance running; the configuration of our legs and hips and our ultra-efficient cooling system gives us an edge at that, even over our closest runners-up, the wolves and the African 'jag hond'. We're not all that fast, but we're extremely enduring -- humans in really good condition can run any other animal on earth to death.

As an ability, this is useless in evading predators. But it's very useful indeed in chasing prey animals.

Sean M. Brooks said...

Dear Mr. Stirling,

Again, very interesting comments! I had not quite realized that Homo erectus and its successors had bodies designed for long distance running. Which would be useful for running down prey animals.

I'm sure you have read PA's "The Little Monster." That story interests me as showing when primitive humans really began their rise. Was it because our remote ancestors mastered FIRE that they began to become dominant over large predator animals?

And I can see how, absent agriculture, earlier humans had to live almost wholly on hunting for meat.

Sean

S.M. Stirling said...

Well, humans always foraged as well as hunting, but the design of our digestive system is biased towards meat -- meat is a much more concentrated food.

Early hominins like Australopithecus have, like chimps and gorillas, a flared rib-cage to accomodate a huge gut, necessary to process a lot of green roughage.

Humans (and our predecessors since h. erectus) have a barrel-shaped ribcage, matched to a shorter and simpler digestive tract.

This seems to indicated a transition to a more predatory lifestyle. Chimps hunt small animals and love the taste of meat, but that's a fairly rare treat for them and probably was for our own very remote ancestors.

We're an ape that first became bipedal, and then started to become a specialist predator. That required some tool use, but tool use is very old -- and all humans really need to hunt is wooden spears and clubs. Spears are definitely at least 500,000 years old and probably much older.

S.M. Stirling said...

So we -can- survive on plant foods, but humans generally don't unless they have to -- agriculture represented a step down the food chain. I suspect we retained the capacity to do so as an emergency back-up, for times of famine.

Sean M. Brooks said...

Dear Mr. Stirling,

Aha, the flared rib cage of Australopithecus, chimps, gorillas, etc., came from them being mainly plant eaters. And needed a much larger gut than meat eating lines beginning with Homo erectus.

Hmmm, crude wooden spears, clubs, and fire enabled early humans to become apex predators after becoming bipedal.

And the fact we still like to eat bread shows we cam still eat plant foods.

Sean

S.M. Stirling said...

Well, it's important to avoid the teleological fallacy when thinking about evolution. We didn't become bipedal to become predators; becoming bipedal made a predatory strategy a possible evolutionary adaptation for our ancestors.

We became bipedal about 5 million years ago, or possibly a bit more. Our particular line became predators about 2 million years ago, or a bit less.

It proved to be a very successful evolutionary adaptation, because the type of predation we developed was so generalized it could be adapted to many different environments -- hence the radiation of h. erectus out of Africa to virtually the whole of the Old World.

S.M. Stirling said...

There are other indications in the h. erectus body-plan. For example, the shoulder structure (identical to ours, pretty much) allowed efficient throwing. A trained human being can throw a fist-sized rock at over 100 mph and usually hit what they're throwing at quite a distance. Few animals can stand up to say 10 men throwing rocks at them with speed and accuracy.

Sean M. Brooks said...

Dear Mr. Stirling,

Again, many thanks for your interesting comments. Only goes to show I need to do some serious reading in anthropology. Becoming bipedal and the human shoulder structure ALLOWED early humans to become efficient hunters, etc.

Sean

S.M. Stirling said...

The more so because many adaptations are multipurpose; throwing rocks is both an offensive and defensive strategy, for example.

And we kept getting smarter long past the point where we needed more reasoning capacity to deal with the immediate challenges of our non-human environment -- hominins were a very widespread and successful group of species long before the emergence of modern human mental capacities.

We almost certainly evolved those as a means of dealing with each other -- competing for reproductive success as a social animal, basically.

But increases in mental capacities -also- affected our ability to understand our environment in ways other animals couldn't.

Eg., h. sapiens sapiens shows a much more "granular" adaptation than any other related species.

Human hunter-gatherers form smaller, more specialist cultures and do things like systematically preserving seasonal surpluses (from salmon runs, migratory animals, wild grains and that sort of thing) for consumption later.

This is apparently because of a larger time-horizon and greater ability to plan.

That means a given environment could support a lot more humans, because they were living off the -average- productivity, rather than the -minimum- one, by using seasonal peaks to make up for seasonal dearths.

Human populations were orders of magnitude greater than those of their predecessors like h. erectus or Neanderthals.

S.M. Stirling said...

Humans could also alter their subsistence strategy much more rapidly -- transitioning from specialist big-game hunting to using smaller animals and more plant resources, for example, if the big grazing beasts became less common (not least because of human hunting pressure).

This would only take humans a couple of generations. Pre-human hominins apparently took much longer -- their tool-kits stay stable over many tens of thousands of years and over very large geographical areas, compared to humans.

Sean M. Brooks said...

Dear Mr. Stirling,

Again, many thanks! Hmmm, human adaptations were multipurpose, capable of being used for more than one thing. Intelligence increased at least partly to better handle "social pressures," etc. Increased intelligence led to greater ability to store food, etc. Eventually leading to the invention of agriculture.

Also, Homo sapiens could adapt more quickly than other other hominins or hominids.

Sean

Jim Baerg said...

S.M. Stirling
About the "shorter and simpler digestive tract"

Doesn't cooking 'predigest' food so we can eat plant based food and still digest it with the shorter digestive tract?

Cooking also kills parasites, so it is an advantage for humans eating any mix of meat & plant food.

Sean M. Brooks said...

Kaor, Jim!

That makes sense to me.

Ad astra! Sean