Are we simply complex casing for bacteria?

[Guest Rex Mundi]

I'm not yet a vegetarian, I do still eat meat occasionally, but my research leads me to believe, going by the "design" of our digestive system, that we should be vegetarian.

Every year I visit an old army chum who now lives in France, he is and always has been a veggy, and while I am there I choose to go veggy too... and every time I have left there feeling fantastic, full of life and energy...

then I return to my normal diet and am suppressed and lethargic and apathetic.

Our digestive systems are too long for meat.

[Cambium]

I'm not yet a vegetarian, I do still eat meat occasionally, but my research leads me to believe, going by the "design" of our digestive system, that we should be vegetarian.

Every year I visit an old army chum who now lives in France, he is and always has been a veggy, and while I am there I choose to go veggy too... and every time I have left there feeling fantastic, full of life and energy...

then I return to my normal diet and am suppressed and lethargic and apathetic.

Our digestive systems are too long for meat.

I think we sit somewhere in the middle personally. And that fits with an omnivorous diet. Our brain size increased when we started eating and probably more importantly cooking meat as less energy was required to glean the calories from green stuff and fruit. And along with an increase in brain size, our digestive tract shrank. We never lost the requirement for vegetables and fruit, but we did develop a requirement for meat.

I often ponder how it would pan out over a geologic timescale, if the world switched to a vegan diet. Would we eventually de evolve?

[Guest Rex Mundi]

Fair point Cambium, the cooking bit especially.

I can accept that perhaps we are omnivores... but replace meat with insect protein.... wasp grubs anyone?

[Boojum]

I think we sit somewhere in the middle personally. And that fits with an omnivorous diet. Our brain size increased when we started eating and probably more importantly cooking meat as less energy was required to glean the calories from green stuff and fruit. And along with an increase in brain size, our digestive tract shrank. We never lost the requirement for vegetables and fruit, but we did develop a requirement for meat.

I often ponder how it would pan out over a geologic timescale, if the world switched to a vegan diet. Would we eventually de evolve?

Wasn't so much about calories, it was more about protein. Calories are actually pretty easy to come by from a vegetarian diet (less so with raw vegetables, starch needs breaking down, that's why a lot of grazing animals have evolved multiple stomachs, to break down raw plant matter), but protein (and essential amino acids) are much easier to get from meat.

I doubt we'd de-evolve if we switched to a vegan diet, evolution tends not to go backwards, but I think we've already stepped off the evolutionary ladder - as soon as we started manipulating the world to suit us we kinda moved away from evolution, because evolution is all about species adapting to the world, once you start changing the world to adapt it to you it kinda takes over from the evolutionary process.

Edited April 9, 2015 by Boojum

[Cambium]

Wasn't so much about calories, it was more about protein. Calories are actually pretty easy to come by from a vegetarian diet (less so with raw vegetables, starch needs breaking down, that's why a lot of grazing animals have evolved multiple stomachs, to break down raw plant matter), but protein (and essential amino acids) are much easier to get from meat.

I doubt we'd de-evolve if we switched to a vegan diet, evolution tends not to go backwards, but I think we've already stepped off the evolutionary ladder - as soon as we started manipulating the world to suit us we kinda moved away from evolution, because evolution is all about species adapting to the world, once you start changing the world to adapt it to you it kinda takes over from the evolutionary process.

Yeah proteins is what I meant. I completely understand what you're saying about evolution in that de evolving isn't a thing, its always marching on. It just tickles my fancy to think about fairly wild hypothetical futures, and in one hypothetical future, we all turn to veganism, without technology replacing the protiens i.e global trade. And over millions of years, our brains shrink and intestinal tract enlarges.

I may well just be displaying my own future ruminantary intelligence, but its certainly something I like to think about.

Edited April 9, 2015 by Cambium

[indicatoker420]

There's different types of amino acids too, the ones in say hemp seeds are different to the ones in meats. Protein is made up of several different types of amino acids. I love meat and would really struggle to become a vegetarian.

[Galactic]

Your reductionism doesn't go far enough. We're not even bacteria. We're just animate matter, i.e. an ongoing chemical chain reaction. Everything else is made up in our brains (not even colour exists outside of our minds, colour does not exist in objective physical reality).

The idea that bacteria has a conciousness and is secretly piloting our bodies and feeding our will is ludicrious, because the idea of life or conciousness is also not only ludricuous, but also undefinable. They're just handy labels to stick on matter that appears to move due to ongoing chemical reactions. There is no you. Concepts of identity are learned through socialisation.

[Mephitis]

Your reductionism doesn't go far enough. We're not even bacteria. We're just animate matter, i.e. an ongoing chemical chain reaction. Everything else is made up in our brains (not even colour exists outside of our minds, colour does not exist in objective physical reality).

The idea that bacteria has a conciousness and is secretly piloting our bodies and feeding our will is ludicrious, because the idea of life or conciousness is also not only ludricuous, but also undefinable. They're just handy labels to stick on matter that appears to move due to ongoing chemical reactions. There is no you. Concepts of identity are learned through socialisation.

The parasite Toxoplasma gondii uses a remarkable trick to spread from rodents to cats: It alters the brains of infected rats and mice so that they become attracted to—rather than repelled by—the scent of their predators. A new study reveals that rodents infected with the parasitic protozoa are drawn to the smell of cat urine, apparently having lost their otherwise natural aversion to the scent.

The parasite can only sexually reproduce in the feline gut, so it's advantageous for it to get from a rodent into a cat—if necessary, by helping the latter eat the former.

In rodents, "brain circuits for many behaviors overlap with the brain circuits responsible for fear," said Ajai Vyas of Stanford University, who led the new study.

"One would thus assume that if something messes up fear of cat pee, it will also mess up a variety of related behaviors."

But Vyas's experiments showed that not to be the case.

In fact, his test demonstrated just how precise and efficient the mind-bending parasite is. While manipulating rodents' innate fear of felines, T. gondii leaves other behaviors intact.

Toxoplasma-infected mice and rats retained most typical rodent phobias, including fears of dog odors, strange-smelling foods, and open spaces. Infected rodents also didn't appear to be sick.

Only the animals' response to cats was abnormal: Uninfected rodents avoided an area of a room that researchers had scented with cat urine. But infected rodents actually seemed drawn to the smell.

"Toxoplasma affects fear of cat odors with almost surgical precision," Vyas concluded. "A large number of other behaviors remain intact."

"Brainwashing" Parasites

"There are a million examples of parasites manipulating host behavior," said Robert Sapolsky, a Stanford University neuroscientist who collaborated with Vyas.

In most cases, he said, "they do something terribly unsubtle, like destroying the vision, so [infected animals] are much less capable of avoiding predators." T. gondii, by contrast, "is not just sledge-hammering a behavior out of existence," Sapolsky said.

"It's extinguishing a normal behavior"—avoidance of cats—"and replacing it with this incredibly maladaptive opposite."

Vyas's team found that Toxoplasma, which forms cysts in the brain, tends to concentrate in an area of the brain called the amygdala.

Because that region is linked to fear and anxiety, the finding provides a new clue to how the parasite manipulates behavior.

Sapolsky, Vyas, and their colleagues reported their findings Monday in the Proceedings of the National Academy of Sciences.

Manuel Berdoy, a zoologist at Oxford University in England, called the new finding "a delight."

He and Joanne Webster, a researcher at Imperial College London, had previously found that Toxoplasma-infected rodents gravitated toward cat odors.

The new study advances scientists' understanding of how the parasite pulls off the trick, Berdoy said.

He called it "astonishing that [T. gondii] may be able to target specifically the neural pathways responsible for processing cat odors.

"It's incredible that the parasite would be able to alter a response—cat aversion—that is so ingrained in the rats' psyche," Berdoy said.

http://news.nationalgeographic.com/news/2007/04/070403-cats-rats.html

[Guest Rex Mundi]

(not even colour exists outside of our minds, colour does not exist in objective physical reality).

That part I agree with.

[Galactic]

The parasite Toxoplasma gondii uses a remarkable trick to spread from rodents to cats: It alters the brains of infected rats and mice so that they become attracted to—rather than repelled by—the scent of their predators. A new study reveals that rodents infected with the parasitic protozoa are drawn to the smell of cat urine, apparently having lost their otherwise natural aversion to the scent.

Etc.

http://news.nationalgeographic.com/news/2007/04/070403-cats-rats.html

Ah good point, I remember reading about this a few years ago!

I wouldn't disagree, my main point was that 'life' and 'consciousness' as descriptive labels (whether for bacteria, humans, algae (whatever)) are at best illdefined, at worst make-believe. i.e. I don't disagree that this behaviour occurs, just that it is this idea of there being a 'consciousness' that drives such behaviour.

Playing advocate, is this really a deliberate act on behalf of the parasite in question, or just a happy 'evolutionary' accident for the parasite as it happens to have a behavioural charecteristic which increases it's survival/reproductive success rate?

[Hughie Green]

"We are a virus with shoes"

Bill Hicks

[forest dog]

Playing advocate, is this really a deliberate act on behalf of the parasite in question, or just a happy 'evolutionary' accident for the parasite as it happens to have a behavioural charecteristic which increases it's survival/reproductive success rate?

Absolutely right mate, it is an evolutionary throw of the dice that turned out to be beneficial.

On that subject, I have seen quite a few different insects infected by a fungus that secretes a hormone in the host which makes it climb and then freeze in place. The fungus then fruits out of the unfortunate insect's body and the spoors float down to infect other insects.

The insect world is a seriously scary place.