-—But remember that the word “species” is just a scientific construct, one of many describing biological classifications, including such terms as “sub-species”, “breed”, and “race” which come and go on even shorter time scales.-—
Aristotle classified things (genus/species) according to common characteristics and specific differences.
Modern classification of species assumes that evolution has occurred, because of common characteristics between species. The difficulty is that the fossil record overwhelmingly demonstrates the fact that species are static. They remain unchanged as they enter and exit the fossil record, except for minor variation within species.
-—Indeed, we’ve seen “breeds” of domesticated animals developed over the short span of human history:?-—
This is variation within a species directed by human intelligence. For your analogy to hold on a wide scale, evolution would have to be directed by a great intelligence. Regardless, the fossil record contradicts this idea.
-—It’s a fact, for example, that human bones share certain characteristics in common with every other mammal, including the earliest proto-mammals from over 300 million years ago:-—
This evidence is ambiguous, because it could imply evolution or a common designer.
-— So, yes, “species”, “sub-species” & “breeds” come and go, but fossil records show that larger related families, orders and classes have survived for tens and hundreds of millions of years.-—
I don’t see your point.
The evidence simply contradicts Darwin’s expectation that the fossil record would show an unbroken continuum of change.
-—And the important point here is: DNA analyses of existing (or recently extinct) species confirms what the fossil record suggested — that those with very similar characteristics also have closely matching DNA.-—
Sounds plausible, but THERE IS NO FOSSIL EVIDENCE to support microevolution. You can’t ignore this fact or wish it away. The lack of evidence MUST BE EXPLAINED SCIENTIFICALLY.
Moreover, upon closer examination, this data is not very compelling evidence of evolutionary theory. DNA-sharing is ambiguous evidence, supporting evolutionary theory or a common designer. Are we more closely related to cows, cats or mice? How closely? Are we related to bananas?
Fruit Fly: 60%
-—And DNA has a rate of mutations which can be measured in living species and calculated back to geological time-frames.-—
Cut and paste below...
While it is convenient for evolutionary biologists to assume that various DNA proteins evolve at a fixed rate, a recent study blows a hole in this theory. The September 25, 2001 issue of the Proceedings of the National Academy of Sciences, geneticist Francisco Rodriguez-Trelles and colleagues at the University of California, Irvine, indicate the idea of a molecular clock may be hopelessly flawed. “It may be ripe for the pawnshop” say Menno Schilthuizen, writing in Science Now.
Calculating the different mutation rates for three well-known genes for 78 species, researchers found widely different mutation rates even for closely related species. “Molecular clocks are much more erratic than previously thought and practically useless to keep accurate evolutionary time,” says Schilthuizen. The authors of the research conclude that the neutral theory of molecular evolution (predictable or constant rates of change) is flawed and that changes in the rate of variation are left to the vagaries of natural selection
(randomness). With no evidence to confirm the neutral theory of molecular evolution, scientists say this amounts to a “denial of there being a molecular clock.”
-—And if, for example, that last common ancestor was several million years ago, and if our sub-species had lived all those years in radically different environments, then we might well expect that today our families could no longer interbreed — hence by definition, we’d be different “species”, regardless of how similar we looked.-—
So... WHERE IS THE FOSSIL EVIDENCE?
Eventually scientific hypotheses should address reality.
DNA analyses overwhelmingly demonstrate the fact that species experience genetic mutations every generation, and that the average rates over time of certain types of mutations can be observed and hence calculated.
The majority of DNA mutations have no effect on an organism's appearance or functions, since they occur in genetic areas sometimes refered to as "junk DNA".
Of those mutations which do cause some change in an organism, the majority produce changes which degrade its chance to survive and reproduce, and are therefore not passed on to future generations.
And in the case of a stable environment, where a species has already perfectly adapted, all genetic changes must necessarily be negative, and so the species may not "evolve" for millions of years.
But when the environment changes (i.e., grows colder, or warmer, wetter, dryer, a new predator, etc.) then some mutations will prove more advantageous than others and the species can begin to evolve again.
And that explains the stability of species we see in the fossil records, despite the fact that genetic mutations occur in every generation.
St_Thomas_Aquinas: "For your analogy to hold on a wide scale, evolution would have to be directed by a great intelligence."
All theistic evolutionists -- which means, most Christians -- believe that God does direct evolution, that nothing happens by "accident" and everything is according to God's purposes.
The issue, perhaps, is whether this great machine of God's creation was designed perfectly to, in effect, grow human beings the way a large tree (the Universe) grows from a small seed (Big Bang).
Or did, perhaps, the Universe / machine require God to tinker and modify to insure its results comply with God's plan?
I think the real Aquinas would say that since God is perfect, His creation, the Universe, must be perfectly designed and therefore would not require much in the way of God's direct interventions until the arrival of human beings capable of both rational thought and irrational sinful behavior.
At this point, Aquinas would say, God must step in to provide what Nature alone never can: a path for human salvation.
The Bible clearly tells us that God enjoyed the process of creating His Universe, was well satisfied with His work and at the end of each phase of Creation, "God saw that it was good.".
So we can only imagine how reluctant God was/is to intervene directly in the affairs of sinful humans.
My point is: nothing prevents the science of evolution from being an accurate representation of God's methods of creation.
St_Thomas_Aquinas: "This evidence is ambiguous, because it could imply evolution or a common designer."
Neither rules out the other.
The evidence suggests that God's design was executed through processes described by the word "evolution", those chiefly being 1) descent with modifications, and 2) natural selection.
St_Thomas_Aquinas: "The evidence simply contradicts Darwins expectation that the fossil record would show an unbroken continuum of change."
I doubt if even Darwin originally expressed it as you here claim.
Regardless, scientists have long understood that major changes in well adapted species only happen after major changes in their environments.
Indeed, species whose environments remain stable can survive virtually unchanged for tens, even hundreds of millions of years -- crocodiles and sharks come to mind.
St_Thomas_Aquinas: "Sounds plausible, but THERE IS NO FOSSIL EVIDENCE to support microevolution.
You cant ignore this fact or wish it away.
The lack of evidence MUST BE EXPLAINED SCIENTIFICALLY."
First of all, I don't accept the alleged distinction between "micro-evolution" and "macro-evolution", except in the sense that most evolution occurs in infinitely small steps, "micro-evolution", which over many millions of years can add up to major changes in species: "macro-evolution."
As for fossil evidence, you have only to review the most intensely studied evolution of all -- our pre-human ancestors.
So far, scientists have identified about two dozen species, or sub-species or breeds of pre-humans going back to our last common ancestor with chimpanzees, about six million years ago.
Some of those have been found to be so similar (i.e., Neanderthals) they are thought by some to have interbred with modern humans.
That would mean Neanderthals were not a separate species at all, but simply the result of micro-evolution caused by species isolation.
St_Thomas_Aquinas: "DNA-sharing is ambiguous evidence, supporting evolutionary theory or a common designer.
Are we more closely related to cows, cats or mice?
How closely? Are we related to bananas?"
Again: evolution and a common designer are not mutually exclusive.
How closely are we related to cows, cats, mice and bananas?
Your numbers seem reasonable, in terms of DNA similarities, and when translated into geological terms, they mean maybe 150 million years separating us from cows, cats and mice, but over 600 million years between us and bananas.
So they are all very distant cousins, some more distant than others. ;-)
St_Thomas_Aquinas: "With no evidence to confirm the neutral theory of molecular evolution, scientists say this amounts to a 'denial of there being a molecular clock.' "
In fact, despite various complexities, "molecular clocks" are still powerful tools in understanding the rates of genetic changes over time.
So there is no "denial of there being a molecular clock," but instead there are many "clocks", and scientists must take great care in how the "clocks" are read.
St_Thomas_Aquinas: "So... WHERE IS THE FOSSIL EVIDENCE?
Eventually scientific hypotheses should address reality."
I've already mentioned fossil evidence of about two dozen different pre-human hominid species, sub-species, breeds, etc. -- each only slightly different from the ones before and after.
So what exactly is your problem with addressing reality?