Craig, remember this exchange upthread?
You noted that it’s unfair to expect creationists to provide a stepwise account of what they claim happened by fiat. Good point! But then…
In other words, “Unless you show me how the eye was designed – with machine shops, engineers and plans – I’ll continue to believe it was designed and couldn’t evolve!” You’re asking for the kind of account that, if it existed, would disprove evolution.
Same mistake, just rotated 180°.
Both convergence and descent may provide evidence for evolution. It depends on the pattern in the convergence and descent. Eyes that emerged independently to function quite similarly should have major differences in how they are built and how they are genetically specified. Eyes related by descent that have major functional differences (such as seeing colour, etc.) should have fundamental similarities in how they are build and genetically specified. Evolution can do both “A” (descent) and “not A” (convergence), but each leaves a distinctive pattern.
Similarly, the gospels in our Bibles today may be shown to witness to real people and events in history both by the obvious common descent of various manuscripts of a particular gospel, such as John’s, and by the convergence of less closely related gospels, such as Mark and John, on many of the people and events they record. But we expect different things for convergence and descent. For convergent testimony, we expect a core similarity even though the precise words and grammar and thought structure will differ. For testimony that has descended through the ages reliably, we expect the structure and thought sequence to be virtually identical and most changes to be minor and incremental – except when a copy only preserves a fragment of the whole.
So, both manuscript convergence and manuscript descent can support the thesis that the gospels preserve history, and both convergent eyes and eyes modified through descent can support evolution. In both cases, the key is to dig into the actual patterns of convergence and descent that we find.
That doesn’t really tell us much. Did He wink it into existence with His left or right eye … or did He put into motion conditions from which evolution would arise and stand back? Please support your answer.
It seems to me that, ultimately, whichever explanatory or descriptive route you choose, you’re going to end up with something fundamental that ‘just is’ and which harbours unanswerable questions. For example, in the case of the material (physical) world, you can’t ask what the fundamental stuff is ‘made of’ because it is what everything else is ‘made of’.
For atheists, this fundamental thing or stuff that ‘just is’ will be the stuff that gives rise to the appearance and behaviour of the world we see - for example, what is described by quantum field theory, or whatever underlies it.
For theists, this fundamental thing or stuff that ‘just is’ is also what gives rise to the appearance and behaviour of the world we see, but it generally does so as an ontologically separate entity - in a variety of different guises, from non-intervening ‘first causes’ to interventionist anthropopsychic paternal authority figures.
To the atheist, the theist version is unjustified and unnecessary (e.g. Occam’s razor). To the theist, the atheist version is hollow and incomplete.
Just my take.
I could come up with “what if” and possibilities like evolution, but, just like evolution, they would belong in a story beginning with “Once upon a time, in a galaxy far, far away…”
Some big picture articles have already been cited by Christy early in this thread. What do you think of those two articles?
Also, please bear in mind that when a stochastic process occurs over millions of years, lots of details get lost. And biology is a stochastic process.
Describing an evolutionary history is not the same thing as describing an automobile assembly line because, in principle, everything above the quantum level can be explained in an automobile factory. This is not true of stochastic processes such as stock market indexes and biological evolution.
That you think an auto factory is a suitable analogy makes me wonder how deeply you understand biology.
Best,
Chris
EDIT: Another recent BioLogos thread has links to additional resources on the evolution of vision. I think you will find it illuminating, Craig.
References?
Those multiple designs fall into a nested hierarchy, so why wouldn’t they be evidence for evolution? Bats have a different wing design than birds, and the different designs stay within those lines of descent, exactly as we would expect from evolution.
Creationists need to explain why eye designs fall into a nested hierarchy. Why does everything with a backwards facing retina also have a backbone?
Is God forced to give everything with a backbone a backwards facing retina?
We can observe all of the mechanisms of evolution in action. We can observe mutations, replication, competition, speciation, and natural selection, to name just a few. They aren’t what if’s or possibilities, they are very real and observable mechanisms.
And in over a hundred years of research, not one mutation has led to a second or third in a process toward a new feature in an animal or plant. What they always lead to is useless excess features, degradation, sterility and death.
Quite a broad statement. How would you characterize the mutation that permitted the persistence of lactase in older humans that allowed cultures that domesticated cattle and other milked animals to better use milk and make cheese, thus improving their nutrition? While vegans might object, I think the ability to eat ice cream without diarrhea is pretty good, and like having that mutation.
Hi Patrick -
I appreciate your sincerity. Your command of the biology research literature probably needs a little reinforcement, however. Here is a popular article describing how biologists have discovered the mutation-by-mutation pathways to two different antifreeze genes in different fish species.
Best,
Chris
What about the mutations that separate humans and chimps?
That isn’t quite what I meant, but taking it as fact, doesn’t change the fish. The otothens are still otothens, and the Arctic Cod are still Arctic Cod.
One thing that tells me his bias is this:
They found a hit—but in a functionless stretch of cod DNA that doesn’t include any genes at all. Somehow, this region of useless junk gave rise to a new and very useful gene.
And then total fantasy.
First, through random chance, a short stretch of junk DNA was duplicated twice, creating four identical segments in a row. The stretches between these segments were very close to the code for the thralala unit, and through a single mutation, one of them turned into exactly the right code. This snippet then duplicated, over and over, creating the core of a new antifreeze gene.
And right into Lamarkian evolution. Why is not science. Why is religion, or philosophy.
We not only know that it evolved, but also why —to prevent the cod from icing over.
What about them? We aren’t related, just created similarly. Mutations will kill an animal long before creating any new kind.
Aren’t the genetic differences between chimps and humans responsible for the physical differences between the two species? Aren’t those differences useful for each species?
If changing a genome will kill an animal then how are humans and chimps able to survive when there are ~40 million changes between our genomes?
First, Do they have actual DNA from before and after this supposed mutation? From full humans, not supposed ancestors. Remember the Goddidit arguments also apply to mutationsdidit.
The Smithsonian mag seems to lead with the conclusion and base its findings on what they want to see. How can they prove which way the change went, from tolerant or intolerant?
Differences, not mutations.
We aren’t directly related. We have similarities and differences, not changes.
Actually, it appears to be a relatively complex story, but fascinating.
They are single base substitutions in an intron upstream of the human lactase gene. Are you saying substitution mutations don’t happen?
Let’s do a little math. Each human is born with 50 to 100 substitution mutations. These are mutations that change a single base. There are 6 billion bases in a diploid human genome, and 3 possible
substitution mutations at each position in that genome. That means there are 18 billion possible mutations. 18 billion divided by 50 mutations is 360 million which means you need about 360 million births to get every possible substitution mutation in the human genome. There are enough humans on the Earth to get every possible mutation 19 times over. Not all mutations have the same probability, bu this is a rough back-of-the-envelope calculation.
So can you explain why you think this is such an impossibility for a single substitution mutation to result in lactase persistance?
What’s the difference between them? If mutations created the same ~40 million differences between humans and chimps would it have a different outcome?
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