why are there more small animals than large animals?

Discussion in 'Earth Science' started by Raize, Jun 19, 2007.

  1. Raize Registered Member

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    Anyone have any ideas or articles I can take a look at?
     
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  3. nietzschefan Thread Killer Valued Senior Member

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    They require less energy(food) generally...
     
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  5. Raize Registered Member

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    i also think they are more specialized

    is there any scholarly articles that address this issue? maybe from ecology
     
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  7. Fraggle Rocker Staff Member

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    Thermodynamics. Surface area available for dissipating waste heat increases as the square of linear dimension. Whereas the mass of tissue creating the waste heat increases as the cube of linear dimension. In other words, if an animal grows twice as large in any one dimension, it has eight times as much heat to dispose of, but only four times a much surface area. Eventually it reaches a point where it's difficult to maintain an efficient metabolism.

    There's a reason that the world's largest animals were reptiles. They're cold-blooded, meaning they don't generate internal heat. The only mammalian exceptions are the whales, and they live in an aquatic environment which very efficiently conducts and convects away their waste heat. Really big mammals like hippos and elephants spend a great deal of time either in the water or pouring water on themselves.

    During the ice age, mammalian "megafauna" did exist, but only in the coldest latitudes. Woolly mammoths and woolly rhinoceros were all enormously larger than their present-day cousins. Size is an advantage in freezing weather, and today the largest bears (polar bears) live in the arctic.
     
  8. iceaura Valued Senior Member

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    There's a book: "Why Big Fierce Animals are Rare". Library.

    One way to look at it: There's only so much life support available in a given area. You can make ten elephants with it, or ninety thousand mice. More likely, one elephant and 81 thousand mice.
    Dinosauers. Their actual coldbloodedness is up for debate - some definitely weren't, apparently.

    Many dinos had large sails or fins, huge flat crests and head ornaments, etc - there's been speculation (and data) that these things were for dissipating heat.
     
  9. Raize Registered Member

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    Very persuasive argument FR, thermodynamics definitely plays a big part. I wonder what the argument about environmental restraints would be.
     
  10. Raize Registered Member

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    Thanks I just reserved it, gonna pick it up from the library tomrrow.
     
  11. pjdude1219 screw watergate i want to know about zaragate Valued Senior Member

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    and larger animals require larger habitats as humans destroy animal habitats the is more pressure on larger species so they die off quicker
     
  12. S.A.M. uniquely dreadful Valued Senior Member

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    They're faster and harder to kill. They can have more babies. They have shorter lifespans. They eat less.
     
  13. Starthane Xyzth returns occasionally... Valued Senior Member

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    No they weren't. Common woolly mammoths were probably a bit smaller than the Indian elephant on average (after all, they had less food available); only the more ancient Imperial mammoths grew considerably larger than modern elephants. Woolly rhinos were comparable in size to the living white rhinoceros, although their horn was certainly longer (if the species had survived until modern times, that horn would have become deadlier to its bearer than to any other animal..

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    ).

    Plus, there were also megafauna in the warmer parts of the World: like the giant ground sloths of South America and the diprotodon of Australia.
     
  14. pjdude1219 screw watergate i want to know about zaragate Valued Senior Member

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    simple rabbits well f*** like bunnys
     
  15. Wisdom_Seeker Speaker of my truth Valued Senior Member

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    because they can´t evolve with us in the way
     
  16. mikenostic Stop pretending you're smart! Registered Senior Member

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    There is speculation that size is the reason that Neanderthals died out and us smaller humans survived.
     
  17. one_raven God is a Chinese Whisper Valued Senior Member

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    You have a point.
    You can feed a lot more people with the meat from one Bison, than 1,500 mice, so hunt Bison.
     
    Last edited: Jun 19, 2007
  18. Baron Max Registered Senior Member

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    That's true. But even without humans around, the larger habitat requirement would necessarily limit the numbers of larger animals. They simply require more food, more space, more water.

    Baron Max
     
  19. GeoffP Caput gerat lupinum Valued Senior Member

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    I think we probably just wiped them out.
     
  20. Wisdom_Seeker Speaker of my truth Valued Senior Member

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    Dinosaurs did it, they were huge MFs
     
  21. Baron Max Registered Senior Member

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    Dinosaurs did ...what???

    And why do you think all dinosaurs were "huge MFs"?

    Baron Max
     
  22. mikenostic Stop pretending you're smart! Registered Senior Member

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  23. Wisdom_Seeker Speaker of my truth Valued Senior Member

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    They grew up to be very, very big.
    Not all of them, but many of them man.

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    "The giant plant-eating Turiasaurus riodevensis, recently discovered in northern Spain, measured up to 120 feet (37 meters) in length and weighed as much as 48 tons, scientists say."

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    http://news.nationalgeographic.com/news/bigphotos/15087612.html

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