Common Misconceptions Re: Evolution

by cantleave 83 Replies latest watchtower beliefs

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  james_woods

  Agreed, but what makes one species able to survive when the other doesn't?

  Well, take for example the Manx breed of cat - they are completely tailless. They survived because the Manx people (Isle of Man) LIKED THEIR LOOKS and selectively bred them - thus, on that island this breed became dominant. Note that they are tailless because of a genetic variation, not because the Manx people cut off their tails.

  Another example would be many species on the Galapagos Islands; one example is the only known species of Iguana which deep sea dives to find sea bottom plants to feed on. They have not only behavioral differences, but also physical adaptation.

  The Komodo Dragon is another case: They might well be extinct if there were another top predator on their islands, but they turned out to be the top of the predatory chain for now. Human intervention, or new invading species, could change that in the future.
• 

  PSacramento

  Natural selection is the key driver of evolution, It is clearly demonstrated in a number of areas - gene selection, population change, genetic diversity, and so forth. There are, or have been, controversies between scientists such as Gould and Dawkins regarding whether other mechanisms play a larger role, such as species selection vs gene selection, and other discussions regarding puncuated equilbrium and so forth, but frankly, there is no scientific dispute as to whether natural selection is a fact, and a key driver of evolution.

  And what drives natural selection, what make one species evolve and another not?

  Natural selection can drive itself, can it?

  Also, Psac, what does this mean? "There is no way to demonstrate that MAN, for example evolved from Species A and dublicate it in a laboratory experiement." There IS a way to show that man evolved from "Species A", and it is called evolutionary genetics. We have already clearly demonstrated the genetic development of man and chimpanzees from a common ancestor. Of course, we can't replicate it in a lab - because of various other scientific difficulties with producing living organisms, not because we don't have it clearly demonstrated.

  If its been so "clearly demonstrated", why the shepticisim by so many?

  What was this "common ancestor"?

  I do believe that ALL life form on this planet started from one source of life and that, of course that source had a source, but it doesn't change that we DON'T know what that source was, do we?
• 

  zoiks

  And the cause of all those? and WHY we can adapt? where does that come from?

  I'm not sure of the WHY that you refer to. The mechanics themselves are simple: DNA replicates itself imperfectly, all the time. Otherwise everything would be a perfect string of clones. The imperfectly replicated and spliced DNA causes variation and mutation. These have a chance of being passed on to the next generation. Beneficial variations and mutations generally have a greater chance of being passed on. Repeat ad nauseum. Life is just degrees of variation; nothing is fixed.

  Maybe I totally misunderstand your question, Psac...
• 

  PSacramento

  James, you seem to be implying that the environment dictates which species will survive, yes?
• 

  PSacramento

  I'm not sure of the WHY that you refer to. The mechanics themselves are simple: DNA replicates itself imperfectly, all the time. Otherwise everything would be a perfect string of clones. The imperfectly replicated and spliced DNA causes variation and mutation. These have a chance of being passed on to the next generation. Beneficial variations and mutations generally have a greater chance of being passed on. Repeat ad nauseum. Life is just degrees of variation; nothing is fixed.

  It sounds liek you are syaing that things JUST ARE the way they are because that is the way they are...

  Why woudl you say that DNA relicates itself imperfectly of that replication leads to survival of the fittest" or genetic mutation that is benefical?

  Or does survival of the fittest and genetic mutation not depend on DNA replicating itself to handle "imposed demands"?
• 

  zoiks

  If its been so "clearly demonstrated", why the shepticisim by so many?

  It must be noted that 99% of the skepticism is not coming from scientists.

  Natural selection is simply a term for the result of selection pressure being placed on organisms by their environment. The organisms' genetic makeup provides the raw material. Selection pressure from outside sources such as predators and environmental factors provides the means to sort out what survives long enough to pass on its genetic material...and what doesn't.
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  PSacramento

  It must be noted that 99% of the skepticism is not coming from scientists.

  Perhaps.

  Natural selection is simply a term for the result of selection pressure being placed on organisms by their environment. The organisms' genetic makeup provides the raw material. Selection pressure from outside sources such as predators and environmental factors provides the means to sort out what survives long enough to pass on its genetic material...and what doesn't.

  So, the environment drives the proces we call natural selection to cause our DNA, that is equipped with the tools to, cause an evolution in a species to better adapt to those demands imposed by the environment?
• 

  james_woods

  James, you seem to be implying that the environment dictates which species will survive, yes?

  Pretty much. It does not selectively CAUSE various genetic mutations, but it selects whether they are viable or not. Of course, some genetic mutations can (of themselves) prove to be fatal, so you cannot really blame THAT on the environment.
• 

  PSacramento

  It is amazing how life works, isn't?

  From nothing but "space stuff", cells come to be and those cells have the building blocks to do all that we are finding out they can do.

  Amazing.
• 

  zoiks

  I don't believe that the environment causes our DNA to do anything. It self-replicates, and variation occurs. This doesn't always work out well for a species: 95% of every species that has existed on earth has gone extinct. Also, some species go for long periods of time with little or no change, whereas some changes have happened very quickly, in geologic terms.

  So, PSac, whatcha getting at?

  Edit: I see that I pretty much duplicated James' post.

  PSac - it IS amazing, regardless of one's beliefs.