From Carnivore to Herbivore

smooth wombat wrote in to mention an a recent discovery in the field of evolutionary biology. From the article: "A surprising discovery in Utah has paleontologists scratching their heads and asking: Why would a carnivore evolve a herbivorous diet? The species, christened Falcarius utahensis, belongs to a dinosaur group called the therizinosauroids. These are mostly thought to have been plant eaters. But the recently discovered fossil, the most primitive therizinosauroid found so far, seems to have survived on a mixed diet of meat and vegtables...The switch to vegetarianism is surprising, says Paul Barrett, who studies dinosaurs at the Natural History Museum in London. The therizinosauroids belong to a larger group of dinosaurs known as theropods, and many of these are known to have been excellent at catching a meaty meal. "

Comments

Not that surprising.

[Sheetrock]

There are environmental pressures to carnivorism for species that are climbing the food chain because of competition, and environmental pressures to herbivorism for those who top it for longevity (running out of lower elements on the chain to eat.)

Humans, incidentally, have been natural herbivores for hundreds of thousands of years -- one can live longer and healthier as a vegetarian than as a carnivore strictly speaking. But we are considered omnivores because our bodies can tolerate meat as well as plant matter. It is not surprising to see a similar evolution taking place in other species as well; what is surprising is our relative level of resistance to this fact.

Re:Not that surprising.

[figgypower]

You seem to be preaching vegetarian superiority without anything to back up your claim. Humans are omnivores, because we're smart (i.e. we learned quickly to evolve in such a manner or we die off). Being an omnivore gives us the best strategy for survival, period. Indeed eating plants can be more efficient for a human's diet and it certainly provides valueable nutrients not otherwise available. However, our brains evolved to its current state thanks to a compact source of lots of protiens and many calories -- meat.

Refrences:

Should American Eat Less Meat

Humans Head Start [it's a PDF!] I'll even concede the meat might've more likely been fish met, but it was meat.

Did African Hominids Eat Meat We're not really natural herbivores at all...

I'm sure I can Google more out if necessary. We had a natural inclination towards meet as our food stuff became distributed over a wider area. We didn't have the ability to fight for the food stuff with larger animals, so we turned to meet.

I also realize that there is one piece of conflicting evidence to all this. Richard Wrangham and a few of his colleagues have argued that cooked tubers were really responsible for the massive growth of our ancestors' brains. The problem? This massive brain growth was roughly 1.8 million years ago (which Wrangham agrees), but at best we were able to control fire about 300,000 years ago. Quite a disparity. Not to mention that there's no archaelogical proof of such a diet.

So where do you get your B12 from?

[Hamster Lover]

Now I am not an authority on this, but vitamin B12 is only found in amounts sufficient for our dietary needs in animal products like meat, fish, eggs, and dairy and is essential for proper nervous system function. If you're one of the "strict" vegetarians out there you must supplement your all vegetable diet with B12 or run the risk of developing nerve damage or neurological disease (among other complications). You cannot meet all of your dietary requirements from an all-vegetable diet unless you take supplements.

While I would agree that a vegetarian diet is certainly healthier than what most people eat, the fact is a balanced diet from all the food groups including animal products is not only wise but absolutely necessary for a healthy human body. If my memory of biology class is correct just about every herbivore has to eat an enormous amount of plant material to sustain themselves, with specialized digestive sytems. Why do you think a cow has four stomachs?

I watched my sister fade away on a stict vegan diet and even with supplements it wasn't enough. She re-introduced a weekly serving of meat and noticed a huge improvement in her mood and energy level. Her experience taught me that a balanced diet is more important than focusing on any one particular food group and my diet is the better for it.

Re:Why is this so confusing?

[Muhammar]

Rabbits have a simple digestive structure. Their trick is to eat food twice - they are quite fond of their own poop. Something like 50% of their poop ends up re-eaten, depending on their actual nutritional needs. The same goes for rats.