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Education Science

From Carnivore to Herbivore 347

Posted by Zonk from the going-for-the-salad-bar dept.
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. "
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From Carnivore to Herbivore More

From Carnivore to Herbivore

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  • Intelligent Design? (Score:5, Funny)

    by poopdeville ( 841677 ) on Saturday May 07, 2005 @12:27AM (#12460047)
    Maybe the designer wasn't so intelligent after all, seeing as how he kept changing his mind.

  • Hah. (Score:5, Funny)

    by King_of_Prussia ( 741355 ) on Saturday May 07, 2005 @12:28AM (#12460052)
    The next time somebody waxes on about the virtues of the Atkin's Diet I can tell them that even the dinosaurs got sick of it.

    • Re:Hah. (Score:4, Funny)

      by aszaidi ( 464751 ) on Saturday May 07, 2005 @03:23AM (#12460745) Homepage
      The next time somebody waxes on about the virtues of the Atkin's Diet I can tell them that even the dinosaurs got sick of it.

      And look what happened to them.
    • "No one knows quite what killed them, but mass deaths have appeared in the fossil record before. Scientists have suggested drought, volcanism, fire and botulism poisoning as possible causes"

      I think vitamin overdose did them in.

  • Not strictly vegetarian. (Score:4, Informative)

    by Anonymous Coward on Saturday May 07, 2005 @12:29AM (#12460056)
    Not just vegetarian, but omnivorous.

    "Although the team cannot know whether Falcarius was a committed vegetarian - it may have eaten a bit of meat, too - its emergence did coincide neatly with the evolution of flowering plants."

    Why evolve to eat plants and animals? I dunno, but it works for me too!

    "At the same time Falcarius appeared, the world was changing greatly because flowering plants were appearing," Dr Sampson said. "They would have provided a new food source. It could be that Falcarius was exploiting an open ecological niche."

    • Two simple reasons. (Score:5, Insightful)

      by khasim ( 1285 ) <brandioch.conner@gmail.com> on Saturday May 07, 2005 @12:40AM (#12460121)
      Why evolve to eat plants and animals? I dunno, but it works for me too!

      Potatoes don't run fast or put up much of a fight.

      A given amount of land can support more grazers than carnivores.

      Switching to an omnivorous diet means that there will be more of them.

    • What occurs to me is that the incorporation of vegetation into dinosaur diets was probably just an accidental byproduct of aquatic grazing. If fish or other small prey regularly hid within shoreline plants, then it would seem more energy efficient for dinosaurs to grab a mouthful of the plantlife that was hiding the prey too. Natural selection would have probably favored such aquatic grazers by selecting teeth and digestive systems that were most suited for grabbing a mouthful of seaweed or kelp or whatha
    • Why evolve to eat plants and animals? I dunno, but it works for me too!

      Given that the dinosaurs didn't have any Ex-Lax available to them, they found that a little bit of roughage helped pass the time while sitting on a stool.

  • Why is this so confusing? (Score:5, Insightful)

    by Lordfly ( 590616 ) on Saturday May 07, 2005 @12:30AM (#12460062) Journal
    In biology class, one of the things you learn is that plants have the most energy-to-size ratio (i forget the actual term). Then you have the primary group of animals (cows, rabbits, anything that eats plants), then the first tier of carnivores (animals that eat the plant eaters), then you have another tier that eats the first tier of carnivores (us, generally).

    As you go up the food chain, you get less energy from the meat.

    So perhaps this animal simply decided that munching on grass was more efficient than killing a T-rex?

    Josh

    • Re:Why is this so confusing? (Score:5, Insightful)

      by EtherAlchemist ( 789180 ) on Saturday May 07, 2005 @12:43AM (#12460142)

      Another thing learned in basic biology is that an animal, when faced with starvation, will eat what it can, when it can. If the supply of smaller meaty dinos was dwindling or the range of the Falcarius expanded into an area were there were more plants than animals, and the plants could be eaten- then why not?

      This isn't a new or even novel behaviour- cats and dogs are generally considered carnivores thought both will eat plants to get nutrients and fiber when they need them.

      People are the same way- we evolved eating meat most of the year and plants when meat was scarce. We (and many other animals) CAN eat both because we're built that way.

    • Re:Why is this so confusing? (Score:5, Informative)

      by Anonymous Coward on Saturday May 07, 2005 @12:45AM (#12460154)
      >>As you go up the food chain, you get less energy >>from the meat.

      There are a couple of other trade-offs involved that make it less simple. "Pure" energy is converted less efficiently into meat, yes. But digesting meat as opposed to vegetables can be easier (less celulose) and allow simplification of digestive structures (drop the appendix, ditto multiple stomachs). Meat converts more efficiently into energy. Herbivores have to eat in bulk and spend most of their time foraging or digesting. Carnivores can go longer without food. But they have to hunt the stuff down.

      I don't think this is confusing either - the balance can tip either way based on circumstances.

    • Not really (Score:4, Informative)

      by Mr. Underbridge ( 666784 ) on Saturday May 07, 2005 @12:56AM (#12460198)
      In biology class, one of the things you learn is that plants have the most energy-to-size ratio (i forget the actual term). Then you have the primary group of animals (cows, rabbits, anything that eats plants), then the first tier of carnivores (animals that eat the plant eaters), then you have another tier that eats the first tier of carnivores (us, generally).

      That's not quite how it works. Plants have to photosynthesize enough to grow and maintain "operations," herbivores have to eat enough plants to grow and maintain "operations," etc. Eventually a top predator is ultimately eating a lot of plants more because there are a lot of middlemen.


      As you go up the food chain, you get less energy from the meat.

      There's generally more energy in meat, and it's denser so you spend a lot less time eating meat calories. Of course, finding and killing that meat is a different story. I expect the answer to our question is one of relative scarcity or competitive ability - perhaps a different predator took away the market?

      But it's not one of energy density, most definitely.

      • More like, there's a natural pyramid of energy in nature. Plants originate most all the energy available in an ecosystem, so they define the maximum amount out there. Consuming and converting plants to energy takes some effort, so its not 100 percent efficient. The same goes for animal meat, so each predatory level has less resources to prey on. It isn't that comsumption of meat is less efficient than plants, there's just less of it to go around as you go upwards.

        I do recall being told in my biology class
    • I doubt that very much. 100g of beef has a lot more energy in it than 100g of vegetables. Plants are not a good source of energy at all. You only eat vegetables/fruit for the vitamins, and meat for the energy.

  • Dang (Score:3, Funny)

    by skilm ( 319925 ) on Saturday May 07, 2005 @12:32AM (#12460078) Homepage
    I didn't know PETA has been around that long...

  • goD put that omnivore fossil out there to confuse scientists and test the faith of evangelists. hE had so much free time after creation that he wanted to play some tricks and enjoy looking at the morons that hE created for hiS amusement.

    • Actually it makes me wonder why the taliban and fox news haven't thrown fits about this story. I mean evolution is just a theory right? It's not like it's a science or anything.
      • Actually it makes me wonder why the taliban and fox news haven't thrown fits about this story.

        It'll never run in Kansas. The newspapers would have crosses burning on their lawns. After they've settled Darwin's hash, next, pi = 3, and as for the Copernican so-called "theory"...

  • Carnivorous isn't superior (Score:5, Insightful)

    by vlad_petric ( 94134 ) on Saturday May 07, 2005 @12:34AM (#12460087) Homepage
    For example, "lions can spend as much time as 20 hours per day sleeping" -- wikipedia [wikipedia.org]. At the same time, a gnu antilope (not GNU/Antilope) needs only about 6 hours of sleep per night. And yes, this is because of their diet.

    Furthermore, the chain for a carnivore is simply longer by one (plants->herbivores->carnivore)

  • Carnivore... (Score:5, Funny)

    by Etherwalk ( 681268 ) on Saturday May 07, 2005 @12:34AM (#12460090)
    Am I the only one that saw the headline and thought of a new FBI internet tap [wikipedia.org] with a friendly plant-like image?
    • My thoughts exactly.

      I just figured that they wanted to give Homeland Security (AKA the distruction of civil liberties) a friendlier name.

    • Dept of Homeland Security will also be called "Dept of Defense of Happiness" and the "Patriot Act a.k.a. Remove All Freedom" will be known as "Cuddly Bears for Toddlers Act"
  • maybe after after the protest of a bunch of dinosours calling themselves "greenpeace" got them to change their minds and they turned all environmental?

    (seeing how the lower you go in the food chain, the more energy efficient it is..)

  • I haven't eaten meat (or fish) for 20 years now. I feel great, and look a lot younger than i am. Perhaps the critters found themselves in an abundance of readily available, high-energy greens and decided it was much less work than trying to catch & kill their next meal.

    The creature's thigh bones were longer than its shin bones, suggesting that it could run at an impressive pace. "The legs are still adapted for running after prey,"

    Well, the sorts of things a cheetah chases can run pretty bloody fas

    • So where do you get your B12 from? (Score:5, Interesting)

      by Hamster Lover ( 558288 ) * on Saturday May 07, 2005 @02:17AM (#12460459) Journal
      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.
      • veganism is a LOT harder than straight vegetarianism -- access to dairy and eggs makes everything a lot more straightforward, and problems with energy levels are much less common (in fact if you suffer from that, you're clearly missing something). however, you can get veggie B12 from nutritional yeast (saccharomyces cerevisiae), which you can take as supplement, fortified cereals, and fortified (soy) milk.

        i've been vegetarian --no meat, no fish-- for 18 months now, and to bo honest it's very easy to get a
      • 10 years as a strict vegetarian with no supplements and mostly eating my vegetables raw (and university life taught me to eat only once a day to save time,) still alive and kicking, but I guess I shouldn't be alive or should be a nervous wreck by now? Hmmm.

    • AFAIK whilst eating vegetables is good for humans, eating fish is _very_ good for humans. Whilst humans can survive on vegetables, it is easier to _thrive_ if you add fish to your diet.

      There are plenty of scientific studies proving that.

      People in countries with a high rate of fish consumption live longer and healthier for longer.

      Of course the sad thing is the fishing industry is screwed up and the seas aren't getting much cleaner.

  • Pandas (Score:3, Interesting)

    by Theovon ( 109752 ) on Saturday May 07, 2005 @12:41AM (#12460127)
    Correct me if I'm wrong, but pandas eat mostly bamboo, but they evolved from carnivores and are still enticed by the smell of meat.

    So how is this anything new?

  • Not that surprising. (Score:4, Interesting)

    by Sheetrock ( 152993 ) on Saturday May 07, 2005 @12:42AM (#12460131) Homepage Journal
    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. (Score:5, Insightful)

      by xenocide2 ( 231786 ) on Saturday May 07, 2005 @01:10AM (#12460257) Homepage
      Humans, incidentally, have been natural herbivores for hundreds of thousands of years

      Ah yes, you bring to mind the ancient cave paintings of carrots, apples and bottled water. Your statement is further backed up by general recommendations that modern strict vegetarians take vitamin supplments to alleviate the deficiencies in Vitamins B12 and D.

      • Re:Not that surprising. (Score:5, Informative)

        by Anonymous Coward on Saturday May 07, 2005 @01:21AM (#12460296)
        >alleviate the deficiencies in Vitamins B12 and D

        Vitamin D is a hormone you synthesize in your skin from exposure to ultraviolet light (usually from the Sun). You might be interested to know that Vitamin D is ADDED to milk as a supplement.

        B12 is from bacteria in soil. Historically it was also present in running water as it erodes soil. Modern agriculture depletes topsoil and consumers over-clean produce; historically you would eat a little dirt and thus get the B12, which has an RDA in MICROgrams.

        Staying indoors and avoiding dirt are both side-effects of modern living, but evolutionarily, there is no reason being a plant-eating human would cause a deficit of these nutrients.

        Modern life makes up for shortcomings with a pill. So, take your pick.
      • Actually the paintings do not realistically reflect the diet of the early man. Recent studies have shown the early men ate mosly rabbits and other small creatures which they caught with nets. My guess is that the women netted the animals and prepared them while the men painted the walls. They painted rare heroic acts like hunting large animals while every day meals like roots, grubs, rabbits etc did not get any screenplay.
      • B12 is naturally found from bacterial sources (i.e., animal liver, etc.) -- the main problem in getting it is that we are too clean. (Interestingly enough, people who don't wash their hands after using the bathroom will have less likelihood of developing a B-12 deficiency...)

        And I'm pretty sure we can get Vitamin D by staying in the sun. So, from an evolutionary standpoint, it seems that vegetarianism (veganism, really) would be a primary method of food consumption.
      • Hmm, funny, I don't take any B12 or D, or any supplements for that matter. Don't need any, everything is met with my vegetarian diet.

        Ah, you must mean the vegetarians who eat fast food, same reason many meat-eaters are taking B12 and D as well as other nutrients(calcium, etc..) after seeing their Doctors.
      • Ah yes, you bring to mind the ancient cave paintings of carrots, apples and bottled water.
        Don't forget the tofu- they had to get their protein from somewhere!
    • 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 calor
      • Most people now actually contend it was the enviroment that caused humans to get bigger, which accounted for the increase in brain size, not the fact that the food was denser in calories. (Men, on average being bigger than women, have bigger brains than women, on average.) The competing theory to what you said above was also that much of the denser foods were fruits such as avocado and others with a higher amount of fat as well as meat(and quite often depending on the season).

        A good site is:
        http://www.eco [ecologos.org]
    • We can somewhat tolerate meat, that's why most(not all!) of it is cooked. Try eating raw beef for a week, bloody and all. If you live go to the emergency room. =)
    • But we are considered omnivores because our bodies can tolerate meat as well as plant matter.

      Most humans are very good at relying on fish as a protein source. If you're looking for a diet that is healthy, rather than trying to fit some ethical code, low-in-oil fish are an excellent choice. Oily fish like salmon work well too, but in modern times they tend to concentrate pesticides.
  • A carnivore requires a much larger hunting area to sustain itself, compared to a herbivore. In a given area, there is only so much prey, and down the food chain biomass is lost. And that's not counting the energy cost of hunting. If you can get whatever you need from plants, then surely it makes good evolutionary sense to cut out the middleman.
  • But the recently discovered fossil, the most primitive therizinosauroid found so far, seems to have survived on a mixed diet of meat and vegtables...

    If they were originally eating a diet of meat and vegetation I believe the proper terminology is "omnivore".
    • It's good that someone realizes that.

      This article seems to be a whole bunch of nothing. Probably butchered what the scientist(s) said. Or there was (more likely) nothing definite to say. Well, we think X ate meat because of all the sharp teeth but Y, a relative, seemed to have eaten some plants. Diet probably evolved.

      Reporter/submitter takes it to say they evolved to herbivores. More likely, they were never true carnivores to begin with. Hell, people would assume a bear is a carnivore and be very wrong...

  • From the Prey's Point of View ... (Score:3, Interesting)

    by rewinn ( 647614 ) on Saturday May 07, 2005 @01:04AM (#12460235) Homepage

    Plants often use predation by another species to facilitate their reproduction, e.g. bird excrement spreads seeds. So perhaps focussing on the dinos has it backwards ... the plants have a positive incentive to encourage the saurians to try a little salad with their mammalburger.

  • How is any of this surprising (Score:5, Informative)

    by benzapp ( 464105 ) on Saturday May 07, 2005 @01:08AM (#12460249)
    No mammal or reptile is strictly a "vegetarian". None of these animals can convert cellulose into glucose, they ALL require bacteria to do this for them. It is obvious why some animals evolved to eat plants: there simply wasn't enough meat available for them to consume. Over time, their bodies evolved adaptions such as larger and multiple stomachs to regulate the gas biproducts of bacterial decomposition of cellulose. This is why humans have to cook their food, we simply cannot survive on a truly natural vegetarian diet. Our stomachs are too small.

    Without exception, all animals can eat meat. Even the cow retains the ability to produce bile acids to break down fat, the primary source of energy for most predator mammals.

    • Raw Foodies are strictly vegetarian without cooking. It's possible, but hard(and expensive!) but it can be done. Only meat has to be cooked, as well as some vegetables that we can't digest. Most vegetables do not need to be, and we, uh, "regulate" the gas biproduct our own way without a second stomach. =)
      • Yeah, I meant to say cooking cheaply. The standard staples of man's diet, ie grains can't be consumed unless cooked. If you are physically active such that you need 3000 calories a day, vegetables will not provide you with any energy. You would have to eat dozens of kilos a day and it would be extremely uncomfortable. Vegetables have never served as a source of energy in the human diet, it has always been a source of vitamins and minerals.

        If you eat a raw diet, you can really only eat fruit, juice, nuts,
    • This is why humans have to cook their food, we simply cannot survive on a truly natural vegetarian diet - then I don't exist? 10 years on uncooked vegetables (my university days trained me to eat only once a day also.)
      • What percentage of your caloric intake came from those vegetables? Very few.

        Sit down and eat a pound of carrots, one of the few vegetables with a relatively high sugar content you CAN eat raw. You will not feel very good and you will have consumed hardly enough to live on.

        If you think about it carefully, you weren't eating a vegetarian diet like a cow. You likely used olive oil, and did consume a larger quantity of cooked grains(like bread) than you care to admit. Especially since you claim to eat once

  • Butthead Dinosaur (Score:3, Interesting)

    by pipingguy ( 566974 ) on Saturday May 07, 2005 @01:10AM (#12460259)

    This [denverpost.com] was hard to track down. Listening to the original description on discovery.ca (TV) I couldn't help but think about Stampy from the Simpsons (1F15).

  • All the fitness that's new. (Score:3, Insightful)

    by Doc Ruby ( 173196 ) on Saturday May 07, 2005 @01:40AM (#12460359) Homepage Journal
    If more energy were available in its environment in plant form than in animal, especially in a sustainable diet, a more fit sauroid would eat plants rather than meat. Evolution doesn't develop towards any goal - it merely is the survival of species more fit to survive in their environment, who get to reproduce and perpetuate their genes. The environment changes, including the evolution and extinction of species depended upon by others, who must then fit a changed environment. Fitness is a game that never ends.

  • Obviously, Falcarius utahensis got a girlfriend.

    Tomato and spinach pizza, wtf.

  • Falcarius utahensis definitely evolved morals and realized that it is moral folly to eat other animals. Definitely.
  • The article seems to think that they saw a empty slot in ecology and filled it...

    "Perhaps certain dinosaurs were pushed along the evolutionary route to vegetarianism because they lived in an area where there was no other plant-eating competitor, he suggests."

    I think that if this where the case there was not just evolutionary pull but a push also. If they lived in area without plant eating competitor it makes me wonder what does a carnivore eat...
  • And here I was thinking that the US govt had revived an unpopular old program...
  • A driving force in plant diversification is said to be resistance of predators. Chemicals like the furanocoumarins (sp?) in wild parsnip developed because they were a natural pesticide. The mutant plant that can make them suddenly flourishes until another species develops a way to work around the defense. Slowly, more predators join in until things are back in balance. Then another mutant develops a new way of doing things and the process begins again.

    The logical implication of this is that any sudden mass

  • Comment removed (Score:3, Funny)

    by account_deleted ( 4530225 ) on Saturday May 07, 2005 @09:29AM (#12461700)
    Comment removed based on user account deletion
  • The dinosaur had a fossilized tail sticker on that said "Meat's no treat for those you eat!"

    --Rob

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