Be careful what you ask for – you might get it.
Bonnie Alba has been writing at length about the "problems" with evolution. In this article, she urges parents to teach children to "think critically about evolution."
What could possibly be wrong with that?
Well, a couple of things.
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Firstly, anyone needs a certain amount of background information before he's able to "think critically" about anything. Suppose you invited grade school kids to "think critically" about what they were being taught. "Think critically" about what you're learning in your American Government classes, or in history classes. The book says George Washington was the father of our country, but should we accept that uncritically?
"Think critically" about arithmatic. Who says 2+2 = 4? Have they tested that for every possible 2+2? While we're at it, let's "think critically" about all those spelling words. Who came up with that spelling for "phleghm", anyway?
Face it. You need a solid base from which to launch your criticism of anything. Lacking such a base, any "critical thinking" is little more than mindless opposition. I'd say we have quite enough of that in our schools as it is.
Secondly, it seems those who want students taught to "think critically" only want criticism aimed at one side. In this respect, they're like the mainstream news media who are perfectly capable of "critical thinking" as long as the target is conservative. Slipshod thinking and forged memos from liberal sources are accepted without a moment's thought.
Let's apply a little critical thinking to Ms. Alba's piece.
* Miller-Urey experiments presented as simulating early earth conditions demonstrating how life’s building-blocks formed. These have been discredited and no one knows exactly what the primitive air-environment was like in the beginning when non-life first popped into life.
Fact: the Miller-Urey experiments were intended to show whether the building blocks of life could form in the absence of living things. They showed that under the right conditions, these building blocks will form spontaneously. Subsequent experiments have shown that similar arrays of building blocks will form under a wide variety of conditions. It would be astonishing if the Earth's early atmosphere didn't resemble at least one of the experiments.
"Critical thinking" about the Miller-Urey experiment without these facts is being critical, and doing very little thinking.
* Darwin’s Tree of Life does not correlate with the fossial record such as the predominant Cambrian Explosion; also molecular evidence does not support a simple branching-tree pattern.
Um... I'd like a few more details about what this claim means. Right now, all the evidence I'm aware of is consistent with a branching tree pattern (really, a nested hierarchy). Perhaps Ms. Alba is thinking of something very different than I think of when I see the words "branching tree pattern", in which case, it would be useful to explore just what it is she's referring to.
One of the problems with all forms of creationism, including Intelligent Design Theory, is that none of these ideas predict any sort of pattern. Any conceivable distribution of life, any conceivable arrangement of living things, and any conceivable assortment of fossils can be "explained" as the whim of the creator/designer. A "theory" that can explain anything at all explains nothing. (This is critical – in the sense of being important – and I'll discuss it later.)
The "tree of life" idea I'm familiar with – the notion that all living things can trace their ancestry back to one primordial organism – is quite consistent with the evidence. Interestingly enough, the molecular evidence is also consistent with a branching "family tree" pattern. More importantly, when researchers go matching up proteins and DNA by relative similarity, there's no reason for these molecular comparisons to form any sort of pattern, unless there's an actual relationship. Not only do they form a pattern, they form a "family tree" pattern that matches the family tree pattern based on the form and structure of living things. (And by the way, this "family tree" was not developed by Darwin. Blame a fellow named Karl Linne, who's also responsible for all those Latin names for organisms.)
* Archaeoopteryx [sic] (don’t ask me to pronounce it) is presented as the missing link between reptiles (dinosaurs) and birds, from which modern birds arrived. Unproven.
If that spelling is used in a school textbook, you have much larger problems than evolution. You have crappy textbooks (an all-too-common problem with textbooks, I'm afraid.)
A smart-alec response to this item would be, at least six specimens of Archaopteryx (are - key - op (rhymes with "hop) - ter (rhymes with "fur") - icks) have been discovered. Which one are scientists saying is the missing link between reptiles and birds? Answer: None of them. No one claims Archaeopteryx is the missing link. Real scientists, and people who have studied the subject with real critical thought, consider Archaeopteryx a fine example of what an intermediate between reptiles and birds would look like. It has any number of characteristics that are considered diagnostic of a reptile, and it has feathers – which are diagnostic of a bird. Archaeopteryx looks, for all the world, like an animal that has acquired some features that are characteristic of birds, and not yet lost those which are characteristic of reptiles.
Is the species Archaeopteryx in the branch leading form reptiles to modern birds? Is it a side-branch, with the actual ancestor earlier in the fossil record? No one really knows.
One thing we do know – a creator or designer who built a creature like Archaeopteryx, and arranged for it to show up in the fossil record at the right time in Earth's history to be an intermediate between reptiles and birds, seems to really want us to believe we're seeing descent with modification in a big way. Critical thinking about evolution has to include critical thinking about proposed alternatives, and here's a case where the proposed alternative doesn't make a lot of sense.
* Homology or similarity due to common ancestry - Darwin’s “descent with modification” doesn’t agree with present genetics observations-explorations.
Ms. Alba needs to be a lot more specific. Homology is based on large numbers of observations, using the same scientific techniques that have been used to sentence people to death for murder. If scientists don't know what they're doing when they're examining animals and fossils, perhaps we need to empty the jails across the land.
If you look at real scientific discussions about homology, you'll find homology is deduced from a lot more than "well, it's in the right place, so it must be a modified arm". Stephen Jay Gould's essay, "The Panda's Thumb" shows us this, in fact, not at all how homology is identified.
It would be very easy to declare the panda's thumb to be homologous to a human thumb and call it a solved problem. The truth is a lot more interesting – the thumb is actually a modified wrist bone. As it grew, it pulled muscles and tendons along with it. Slight modifications in the structure enabled it to function as an extra digit, and it works just fine for stripping leaves off of bamboo stalks. Nevertheless, it shows up in the same place in the wrist that wrist bones appear in other mammals. It has the same basic connections with other wrist bones, albeit changed in form to accommodate the enlarged bone. If the panda's thumb is not homologous to a wrist bone, then some designer went to a lot of effort to perpetrate a hoax.
After enough evidence of this sort has piled up, it's just a lot easier to believe that what looks like descent with modification really is descent with modification.
There is absolutely no empirical evidence for Macro-E but it is inferred from Micro-E (genetic changes within one species), as a “tenet” of Science.
If inference is disallowed, then we have absolutely no evidence for anything in science. All scientific laws, without exception, are inferences from observed facts. Without making inferences about observed facts, we have no patterns, no rules, no laws. All we have is a collection of statements like, "The last time someone did X, he observed Y." Any suggestion that doing X again might result in Y again is an inference.
"Micro-evolution" was also resisted by the anti-evolutionists, until there was no choice but to accept it. The evidence of change was overwhelming. Now, evolutionary change from one species to another has been observed, and the Institute for Creation Research asserts that new species can and do form.:
* ‘No new species have been produced.’ This is not true — new species have been observed to form. In fact, rapid speciation is an important part of the creation model. But this speciation is within the ‘kind’, and involves no new genetic information. See Q&A: Speciation.
N.b., to date, no one has yet produced a definition of "kind". Indeed, creationists routinely disagree over what "kind" any number of organisms belong to.
In any event, those who distinguish between "micro" evolution and "macro" evolution draw the line at the species level. The ICR accepts that "macro" evolution occurs. Reference to "withink the 'kind'" is hand-waving until a definition of 'kind' is available.
"Critical thinking" about anything demands that one first learn all sides of the issue. Ms. Alba has provided a number of links to one side of the issue. The honest critical thinker will also look at the rebuttal. Here are some links to get you started:
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