Ordinary1: “There is still no proof that monkey’s become chimps become humans, etc.”

Actually, the fact that human and chimpanzee DNA are mostly identical except for about 5% is proof that we had a common ancestor. That infers that we evolved from that common ancestor in different ways. All animal life shares common DNA to greater and lesser degrees, which means we sprang from a common ancestor. All flora and fauna have some small amount of common DNA which infers plant and animal life started from a common ancestor.

Now you can argue about how that divergence occurred but every living thing on Earth carries the proof in its DNA that all life evolved from lower forms. The odds of primates having all that common DNA by coincidence is infinitesimal.

That common DNA also infers that life on Earth was begun from a single spark. You’d think that if life arose spontaneously from conditions on Earth, there would be competing life forms with no common DNA. The fact that life all began from a single source leads me to believe that its basic form was introduced from outside the Earth. Perhaps the basic building blocks of life combined over billions of years and combinations out there in the cosmos and just one came to rest on Earth, perhaps in cosmic ice, in the right place where it could flourish.

Tantor on September 19, 2007 at 4:23 PM

jdpaz: “I don’t think anyone’s suggesting that ape and human DNA are so similar because of coincidence. Like a Porsche and a VW, a common designer is just as adequate an explanation as a common ancestor.”

Actually, it isn’t when the designer is an imaginary god while the DNA is real. Evolution is a simpler explanation for the differences between species which have a common origin than an all powerful god who did it with magic.

jdpaz: “Don’t flippantly toss out that 5% difference as being nothing. Do the math and you find that you need to average 120 positive mutations per generation (a measurable thing). We find that here in the real world there is hardly such a thing as a positive mutation (think Downs Syndrome).”

Evolution among a species does not progress linearly but rather massively in parallel. Characteristics of species are tested for fitness to the environment in every individual along with combinations of of characteristics. A successful characteristic of combination of characteristics can propagate throughout the population fairly quickly in terms of generations.

jdpaz: “So where (macro)evolution is measurable, it falls very flat.”

We know evolution happenned by comparing the DNA of different species, which is indeed measurable. They form a rather neat tree full of evolutionary branches. It’s the exact mechanism of evolution that is unclear.

Tantor on September 19, 2007 at 6:06 PM