Moot The Point

“And second the way people are treated when they question some of those claims.”

We’re pretty dogmatic about things like the earth revolving around the sun and 2+2=4 as well. Sometimes when it looks like someone’s being “dogmatic” about something that’s because the contrary suggestion is just plain wrong.

“What ultimately worries me is the harsh response to those who either disagree or don’t fully understand.”

You cannot expect me to feel sorry for you for picking on you so cruelly. You say that evolutionists are “Worshiping at the feet of naturalism.” You call the fossil record “grossly unhelpful”. You call the theory of evolution “dogma disguised as rational science”. You say we answer creationists (those with pre-existing religious biases are the only ones objecting to the theory of evolution) with “flippant dismissal”. You’re making a strong claim that evolutionary theory is transparent nonsense and that evolutionists have been completely unsuccessful at advancing the theory at all.

Then you admit that you don’t know very much about biology, genetics, the fossil record, geology, etc. If you are ADMITTEDLY IGNORANT of these things, WHERE DO YOU GET OFF making the types of comments you made above? I normally don’t use caps shouting, but my alternative is four-letter words here.

You can’t go around making these types of claims and then when you get called on it by real scientists start whimpering that we’re being mean.

I actually am quite patient and willing to explain evolutionary theory to a person who hasn’t got a chip on his shoulder the size of a grand piano. In fact I think it’s fun, which is part of the reason I started my blog.

“But what you’re saying is that evolution is a complex concept, that can’t be grasped by the laymen like me”

Baloney. You probably could grasp much of it, but you don’t seem to have even tried.

“so we should leave it all in the hands of the experts.”

Better to leave it to experts in evolutionary theory than to leave it to experts in creationist/intelligent design propaganda–which is what you seem to have done so far.

“What ultimately worries me is the harsh response to those who either disagree or don’t fully understand. Making fun of people for having valid question (whether they’re educated or not)doesn’t make them change their minds.”

Yes, yes, woe is me! Try not spreading patently false “information” about evolutionary theory and the response you’ll receive will be more to your liking.

Patently false:

“Irreducibly complex organisms, huge holes in the fossil record and a failure to demonstrate random mutation in the creation of complex life are serious and potentially lethal challenges.”

While the definition of ‘irreducibly complex’ seems to morph, systems alleged to be irreducibly complex have been shown not to be. Additionally, multiple scientists have explained how biological systems avoid this issue entirely. In some cases this is due to scaffolding, in which the final system appears IC because it is missing some parts that were present in intermediate stages but later lost as they became redundant. In other cases a system that appears IC is not because during its development a component changed roles from an ancestral role to its modern role (genes swap roles all the time–olfactory genes are used in sperm cells, crystallins are derived from enzymes that were recruited to the eye due to their beneficial optical characteristics, and snake venoms contain proteins related to digestive enzymes). With irreducible complexity Behe is essentially making the same mistake that countless creationists have made before–basing their determination of the probability of a feature evolving upon the assumption that it must have appeared initially in its modern form. This goes counter to the nature of the evolutionary process.

I’m not sure you know what “huge holes in the fossil record” you are speaking about. While some time periods we don’t know as much about as we would like, we have enough from the Cambrian to begin to tell how the phyla are related, enough from later periods to see a clear evolution of fish, enough from the Devonian to see the evolution of tetrapods from lobe-finned fish, then the sauropsids along their line and the synapsids on theirs. We have a remarkably clear trend in therapsid evolution producing first the mammaliforms and then the mammals. In the sauropsids we have a rapidly-improving record of bird evolution, with information growing seemingly exponentially with the discovery of more bird fossils and multiple species of feathered dinosaurs.

Repeatedly we see evolution happening in the fossil record. At this point it would be foolish to conclude that the parts that we don’t have such a great record for must be inexplicable exceptions–evolution did not occur there! The only reason to draw this conclusion is an attempt to support a religious position by resort to an appeal to ignorance.

As for mutation, we have boatloads of mutations. Genomic duplications? Yep, those happened a couple times on the route through vertebrate evolution. Chromosomal remodeling? Happens all the time. Rodents are nice for demonstrating this, they do all sorts of weird things with their chromosomes. Entirely new genes? I have several examples of those at my blog right now (1, 2, 3).

Importantly, the fossil record and information gathered from the genomes of living creatures complement each other.

I’m a little short on time but I’ll take a go. Gould IMO was mostly rediscovering something that Darwin had already proposed. Gould depicts Darwin’s theory as requiring continual slow change, which he essentially did, but then also as requiring that the fossil record show this gradualism in all its stages. Actually in c. 9 of Origin of Species Darwin says,

“One other consideration is worth notice: with animals and plants that can propagate rapidly and are not highly locomotive, there is reason to suspect, as we have formerly seen, that their varieties are generally at first local; and that such local varieties do not spread widely and supplant their parent-forms until they have been modified and perfected in some considerable degree. According to this view, the chance of discovering in a formation in any one country all the early stages of transition between any two forms, is small, for the successive changes are supposed to have been local or confined to some one spot.”

Indeed evolutionary innovation is often easier in small populations since neutral changes can drift to fixation more easily and provide variation for evolution to act upon. One reason that bacteria have not changed very much in the past billion years is their population size is massive and addition to the genome is typically unfavorable (some discussion of this and irreducible complexity here). So at the transitions the population size will tend to be small until some change occurs that enables population growth–perhaps the addition of some new innovation, or even an occurrence such as a mass extinction. This low population size at the transition plus the sporadic geological record makes it impossible that we will ever have a complete record of every single species that has ever existed. But we do not need to have every single intermediate species in order to know that evolution occurred and that two groups are related.

Secondly, Gould has repeatedly been the victim of creationist quote mining, an unethical practice of taking quotations out of context to give them a very different meaning than they held in the beginning, even sometimes to mean the exact opposite. Indeed, this is what Gould was talking about when he said transitional fossils were missing. He was talking about transitions between species, not from one major group to another. To put it in your words, we don’t have great fossil evidence for “microevolution”, but our evidence for “macroevolution” is outstanding!

You can read about how Gould has been quote mined here (see 3.2 especially for the “trade secret” quote), and many other mined quotes are analyzed here.

“How do we know that a intermediary fossil isn’t an entirely different species and not a transitional form?”

Ouch, you made me cringe.

There’s a common misunderstanding about the evolutionary process in thinking that it simply transforms one species into another. Really the key feature of evolutionary transformations is a branching pattern of repeated divergences. So instead of getting a chain pattern, you get a bush. In common parlance transitional species are “missing links” from that chain of species, organisms directly on the line from an ancestral species to the modern one. This is a misrepresentation.

When scientists talk about transitional species, they aren’t talking about a species that was parent to another species, but about a species that preserves traits characteristic of two groups. Archaeopteryx was not the ancestor of modern birds (it appears too late in the fossil record), but from compiling the fossil evidence we know that Archaeopteryx kept many of the features that would have been possessed by that ancestral bird.

We know a lot of relationships of groups–mammals came from therapsids, birds from theropod dinosaurs, ants from wasps, snakes from mosasaurs, etc. But we can’t say with absolute certainty the exact transitional species between the two groups.

The reason we can examine a fossil and call it transitional is not because we know that species was the parent of another, but we know it fits into a larger evolutionary trend. We have multiple fossils of lobe-finned fishes gradually developing bony fins, then adding articulations so these started to become more like stubby forelimbs (more about that here–many other features evolved simultaneously as well). Another evolutionary trend is the gradual modification of the jaw during therapsid evolution to reduce the mandible to one bone and integrate the other bones into the middle ear, as in mammals. We have fantastic transitionals showing this gradual transformation, even having fossils with dual jaw joints as the ancestral joint was lost and a new jaw joint developed. We don’t have to know the exact chain of descent in order to determine these trends are real.

“However doesn’t the therapsid mandible transformation simply display micro evolution which is, by and large, uncontested?”

Well, if you’re asking me I’d say yes you are absolutely right! because IMO macroevolution is microevolution writ large. Enough time and small changes add into very large ones.

Most anti-evolutionists would not consider it microevolution because the changes span the evolutionary histories of three groups, the cynodonts, the mammaliforms, and the mammals, and they have an a priori objection to evolution causing any such transformation.

“And, forgive this question, but how is the existence of a tiktaalik demonstrably different than a separately created fish? My question goes more to the fossil record requiring evolution.”

Are you a young-earth creationist? I got the impression that you favored ID. ID proponents are essentially theistic evolutionists with more supernatural tampering thrown in. An IDer would look at Tiktaalik and say it is transitional, but God had to zap it in order to make it develop these characteristics in its forelimbs, spiracles, and pectoral girdle. A creationist would say that it either was an independently created species or evolved from a very similar ancestral kind (creationists acknowledge evolution, they just place limits on how much of it are permissable–interestingly also saying it can happen much faster than evolutionists would think possible, since some say all felines descended from an ancestral pair of cats on the Ark 4000 years ago!) The problem with ID is design is not apparent in living systems, and no unusual explanations are required to explain the changes in Tiktaalik. The problem with creationism is the whole of the fossil record emphatically contradicts the idea of creation of all genera at approximately the same time 6000 years ago.

For instance, the Cambrian is particularly problematic for creationism. It preserves an ecosystem that would now be impossible. Most of the major species found in modern marine environments are absent. There are no complex seaweeds, no fish, and a variety of bizarre organisms that are completely defenseless and would be a yummy snack in a modern ecosystem. These organisms lived by feeding off of a bacterial mat that covered the seafloor, and these mats are not possible in modern ecosystems because a variety of animals have evolved that can burrow through the mats and shred them. At that time there were not any animals capable of burrowing any deeper than the very top of the substrate. The Ediacaran immediately before the Cambrian is even weirder. Yet creationism cannot explain how these ecosystems were able to survive if these organisms had to compete with modern organisms and cannot explain why there is such strict segregation in the fossil record between ecosystems (easily explained in an evolutionary context, which uses information from geology and physics to recognize a time gap of millions of years between one and the other).

The conclusion that these organisms appeared over large amounts of time is inescapable, and led originally to the idea of progressive creationism, where God made a batch of organisms, then replaced them with a second batch, and so forth. While this gives a nod to the fossil record, it cannot explain transitions between groups that are clearly preserved, although to give progressive creationists credit these transitions were still unknown in the early 1800’s when progressive creationism was popular.

While it is theoretically possible that some deity is periodically popping into existence new species, the information we have so far is that speciation occurs as a gradual process over thousands of years and is explainable by mechanisms we have observed in living species. Certainly if there is a deity sporadically inventing species we have to wonder why he decided to make so many with transitional traits giving the appearance of evolution when evolution was not really occurring. Why make birds that can be confused with dinosaurs or dinosaurs that can be confused with birds? Archaeopteryx’ skeleton is so similar to theropod dinosaurs that one fossil that did not preserve the feathers was misidentified for years as a dinosaur, and we now have dinosaur species that have so many avian features (feathers and skeletal features) that some have suggested they be classified in with the birds.

I actually ran across that on your blog some days ago, and have done some reading about it before. I’m still not convinced that either term is really meaningful (a rose by any other name. . .)

Perhaps what I think of as “microevolution” is really small amounts of macroevolution, and that seems to be the common understanding of it. The creationist understanding of permissable microevolution usually includes speciation from ancestral kinds, so long as not too much of it is happening.

In general I avoid both words.