Debate:Is the theory of macroevolution true?

Post Your Thoughts

Yes

Arguments for * All life on Earth shares common ancestor

• All life on Earth shares common ancestor

1. All life on Earth shares molecular features.
   • Counter: This is not a scientific argument for evolution. First, this argument says nothing about a *process* of evolution. It does not reveal any transitional forms between species, for examples. In fact, lots of DNA evidence tends to disprove transitions from one species to another. Second, there is no objective or scientific way to say one thing is like another. If you insist there is, then you'd have to agree that intelligent design is science also. Note, by the way, that all of Shakespeare's plays "share" similar features, but one play did not evolve by itself into another.--Aschlafly 23:54, 21 December 2006 (EST)
     • Counter: Poor argument. Shakespeare's plays are not capable of reproducing on their own. Reproduction is one cornerstone of evolution that sets living things and nonliving things apart.

     What DNA evidence disproves transitions between species?

   1. Same macromolecules (DNA, RNA, protein)
   2. Same monomers for those macromolecules (five nucleotides, twenty standard amino acids)
   3. Same chirality of molecules. DNA in all complex life forms is right-handed, research suggests[1] that left-handed DNA would work just as well.
      1. If life forms did not have common ancestors we would expect to see a fairly even distribution of left and right handed DNA.
   4. Genetic system:
      • Ribosome structure
      • tRNA structure
      • The universal genetic code (and slight deviations from it)
      • Information encoded in nucleotide polymers (DNA or RNA).
2. Differences between organisms can be explained by known mechanisms of genetic mutation.
   • Counter: There has not been enough time for mutation to generate existing biological diversity.
     • Counter: Lateral gene transfer between viruses and bacteria to more complicated life forms has been proven to occur and can account for increased mutations over time.--TimS 10:20, 19 March 2007 (EDT)
     • Counter: There has been enough time enough time to generate existing biological diversity.
       • Counter: The time argument doesn't help. Decay, scattering, extinction, defects, disasters, etc., all INCREASE over time. Besides, all mutations are harmful.--Aschlafly 23:54, 21 December 2006 (EST)
         • Counter: Mutations are mostly harmful, but not always.
           • Counter: Mutations are mostly inert.--TimS 10:20, 19 March 2007 (EDT)
         • Additional Counter:Decay, scattering and defects are not part of the evolutionary theory. What proof is there that disasters increase over time? The increase of entropy in the universe is not even comparable to the process of evolution, which is the opposite of randomness. Evolution relies on natural selection, which as its name suggests, selects the best adapted organisms to reproduce, not random organisms.
         • Additional Counter: Seedless watermelons are an example of a mutation, so is corn (it used to be tiny). There is no way to claim, let alone prove that all mutations are harmful.--ChrisF
         • Counter: Being seedless is harmful to the watermelon. The fact that it may be helpful to people in no way proves that being seedless is helpful for the reproduction of the watermelon. --Me4real 13:31, 12 March 2007 (EDT)
           • Counter: On the contrary, mutations such as this are beneficial. To take another example, the chance mutation that caused the Banana to come in to existence has helped a single tree spread it's genetic material to most of the globe. Taking a narrow view of what is an evolutionary benefit is to fundamentally misunderstand evolution. An adaptation that causes a plant to establish a symbiotic relationship with the dominant species can be more helpful to a plant's survival than, say, one that helps it spread its seeds wider in the local area.
         • Counter: Ginger/red hair in humans is an example of a harmless, recessive mutation.--

NATURAL genetic changes can only account for diversity within a species. Mendellian genetics has demonstrated the existence of a closed field of genetic changes which can occur through the reproductive process.

1. • 1. The speed of evolution is measured by the darwin (change in an organism's character by a factor of e per million years.) [2]
     2. Evolution in the lab can be as high as 200,000 darwins.
     3. As measured by the fossil record, the average evolutionary rate in the wild is 370 darwins.
     4. A rate of 400 darwins is capable of turning a mouse into an elephant in just 10,000 years.
   • No other (non-human) process has been observed to generate biological diversity.
   • Extensive biological diversity existed before humans had the ability to create new forms by molecular recombination.

1. • Counter: The argument concerning rate of change assumes that biological evolution is described by a linear equation. However, observation and Mendellian genetics theory suggest that evolutionary change is better described by a rational function bounded by an assymptote. For example, it is relatively easy to crossbreed a pure bred dog so that you obtain a mutt or a nearly pure bred dog of another breed. However, it will take an infinite amount of time to entirely replace the traits of the original breed with those of the new breed- the graph of evolutionary change, with change on the y-axis and time on the x-axis, has reached a horizontal assymptote. The dog remains a dog.

-Chris J

1. • • Counter:Um, what? I'm a bit of a mathy person and have some background in genetics as well, and the above doesn't seem to be anything but an assertion dressed up in mathematical terminology. JoshuaZ 14:06, 13 February 2007 (EST)
     • Counter:If a DNA molecule was of infinate length this argument would stand. Since DNA has a finite length it is entirely possible to remove all 'Mutt' genes from a heredetory family of dogs with selective breeding over time. Because of recombinant DNA and meisis crossover it makes it unlikely to occur - but not impossible. Joshua Z is correct, the maths is wrong.