Please turn on javascript in your browser to play chess.
Science Forum

Science Forum

  1. 19 Feb '13 15:44 / 1 edit
    It is a common misconception that evolution always leads to ever greater complexity.
    Sure any complex lifeforms must have come from a simpler lifeforms if you go back far enough into its ancestry, but that's only because the first life must have been very simple indeed! So there is no special evolutionary barrier for some complexity occasionally being evolved out of a lifeform rather than evolved into a lifeform. Just one example of this is the snake that evolved to loose its legs (if you can ignore the snakes vestige legs that are now totally functionless) -by any stretch of the imagination, loosing legs must surely be a 'simplification'. Now we have fossil evidence that whales teeth have evolved to be simplified by going from four types of teeth to just one type of a simple peg-shape:

    http://phys.org/news/2013-02-whale-teeth.html
  2. Standard member Thequ1ck
    Fast above
    20 Feb '13 21:22
    But the genes for whales teeth are still in their DNA.

    Maybe long in the future whales may need to 'switch' that gene back on
    or maybe (and likely) the genes for teeth are still used in whale mouth
    formation.

    I would say that even though the phenotype appears simpler, there is
    still greater complexity in the DNA and thus the potential survivability of
    the species.
  3. 20 Feb '13 23:34
    Originally posted by Thequ1ck
    But the genes for whales teeth are still in their DNA.

    Maybe long in the future whales may need to 'switch' that gene back on
    or maybe (and likely) the genes for teeth are still used in whale mouth
    formation.

    I would say that even though the phenotype appears simpler, there is
    still greater complexity in the DNA and thus the potential survivability of
    the species.
    I could be wrong but I have always assumed that when laypeople talk about the 'complexity' of living things when they say lifeforms evolve to be more 'complex', they generally mean complexity in the anatomy of the living thing as opposed to the 'complexity' of its genes, genetics, adaptability etc.
  4. Standard member Thequ1ck
    Fast above
    21 Feb '13 00:08
    Originally posted by humy
    I could be wrong but I have always assumed that when laypeople talk about the 'complexity' of living things when they say lifeforms evolve to be more 'complex', they generally mean complexity in the anatomy of the living thing as opposed to the 'complexity' of its genes, genetics, adaptability etc.
    "The evolution of biological complexity is an important outcome of the process of evolution. Evolution has produced some remarkably complex organisms - although the actual level of complexity is very hard to define or measure accurately in biology, with properties such as gene content, the number of cell types or morphology all being used to assess an organism's complexity.[1][2] This observation that complex organisms can be produced from simpler ones has led to the common misperception of evolution being progressive and having a direction that leads towards what are viewed as "higher organisms"."

    http://en.wikipedia.org/wiki/Evolution_of_complexity

    Certainly some organisms evolve to be less complex but I would argue that the
    example of whales teeth is not such an example due to an increase in complexity
    of gene content.
  5. Standard member sonhouse
    Fast and Curious
    21 Feb '13 12:36
    Originally posted by Thequ1ck
    "The evolution of biological complexity is an important outcome of the process of evolution. Evolution has produced some remarkably complex organisms - although the actual level of complexity is very hard to define or measure accurately in biology, with properties such as gene content, the number of cell types or morphology all being used to assess an organ ...[text shortened]... e of whales teeth is not such an example due to an increase in complexity
    of gene content.
    I would add that the loss of teeth for whales is an indication of evolving a more energy efficient way to feed, no need to keep grinding food with jaw muscles attached to teeth which has to be pretty energy intensive. Look at cattle or horses, the amount of energy they spend just chewing has to be more pound for pound than on a whale which simply swims into food and they don't have to be going at top speed for that like a predator/pray relation, quick acceleration and such to capture large animals, just swim through a crowd of shrimp or whatever.
  6. 21 Feb '13 13:03
    Originally posted by sonhouse
    I would add that the loss of teeth for whales is an indication of evolving a more energy efficient way to feed, no need to keep grinding food with jaw muscles attached to teeth which has to be pretty energy intensive. Look at cattle or horses, the amount of energy they spend just chewing has to be more pound for pound than on a whale which simply swims into ...[text shortened]... cceleration and such to capture large animals, just swim through a crowd of shrimp or whatever.
    Well since they are swimming around anyway they just have to open their mouths. Propelling their whole bodies through water must take quite a bit of energy.
  7. Standard member sonhouse
    Fast and Curious
    24 Feb '13 13:16
    Originally posted by joe beyser
    Well since they are swimming around anyway they just have to open their mouths. Propelling their whole bodies through water must take quite a bit of energy.
    I think the amount of energy it takes to swim is low pound for pound for whales because of the low drag their bodies have in the water. I would imagine it taking lower energy pound for pound than humans for instance, who have to lift themselves up an inch or two for every step, of course humans get some free energy from falling that inch or two but I bet the amount of energy required is less pound for pound for whales. Don't forget, when they swim, they mass 50 tons and that will keep it going for a while.
  8. Standard member finnegan
    GENS UNA SUMUS
    24 Feb '13 23:07
    Originally posted by sonhouse
    I think the amount of energy it takes to swim is low pound for pound for whales because of the low drag their bodies have in the water. I would imagine it taking lower energy pound for pound than humans for instance, who have to lift themselves up an inch or two for every step, of course humans get some free energy from falling that inch or two but I bet th ...[text shortened]... hales. Don't forget, when they swim, they mass 50 tons and that will keep it going for a while.
    Humans fall an inch or two only if and after they first expend the energy required to lift themselves up an inch or two. Hardly an example of free energy??