Recently, I was browsing through the latest posts over at Evolution News and Views, and an anonymous article titled, Imagine: 60 Million Proteins in One Cell Working Together, caught my eye. By now, most readers at TSZ will be aware that I consider it overwhelmingly likely that the first living thing was designed. However, I’m also highly critical of attempts to over-egg the case for intelligent design. The article I read was one such attempt: it contained some unfortunate errors and omissions.
The author tried to bolster his case by quoting from two articles in the same issues of Nature (volume 537, 15 September 2016): one by Aebersold & Mann, and the other by Huang, Boyken, and Baker. As it turned out, neither paper was about the origin of life: one was about the proteome (or the set of all the proteins in a cell), while the other discussed de novo protein design.
How many proteins are there in a single cell? And how many are needed?
The ENV article was titled, Imagine: 60 Million Proteins in One Cell Working Together. When I first saw that headline, I was a little puzzled. When I hear the phrase, “60 million proteins,” I automatically assume the speaker means different kinds of proteins. But what the author actually meant was: 60 million protein molecules inside a single cell.
“What kind of cell?” you may ask. Apparently the figure of 60 million is taken from a passage in the Nature article by Aebersold & Mann, where the authors are relating some astonishing facts about the proteins in a tiny yeast cell:
A proliferating Schizosaccharomyces pombe cell contains about 60 million protein molecules, which have abundances that range from a few copies to 1.1 million copies per expressed gene.
However, yeast cells are eukaryotic: they have a nucleus. The first living thing didn’t: it was prokaryotic, and it would have been much smaller than a yeast cell. How much smaller? We don’t know. But it turns out that the number of protein molecules in a tiny cell belonging to the bacterium Mycoplasma pneumoniae is only 0.05×106, or just 50,000. That’s three orders of magnitude less than the yeast cell described by Aebersold & Mann.
But the real question we need to ask is: how many different kinds of proteins are there in a simple bacterial cell? It turns out that a typical bacterium requires 4,000 proteins for growth and reproduction, while humans require more than 100,000 different kinds of proteins. Some bacteria, however, need far fewer than 4,000 proteins, according to MicrobeWiki:
In 1995, the entire genome of M. genitalium was sequenced in less than 6 months using the random shotgun sequencing technique. It was found to have the smallest known genome of any free-living organism at about 580 kilobase pairs long, with 479 coding sequences for proteins. For comparison M. pneumoniae has 677 protein coding sequences, H. influenzae has 1703, and E. coli K-12 has 4,288.
382 of the 482 protein-coding genes in Mycoplasma genitalium have since been identified as essential. Dr. Stephen Meyer, in his work, Signature in the Cell (New York: HarperOne, 2009), generously estimates (ibid., p. 213) that a minimally complex cell needs 250 different kinds of proteins. Dr. Michael W. W. Adams, in an article titled, The Influence of Environment and Metabolic Capacity on the Size of a Microrganism, makes a similar estimate: in a nutrient-rich environment, a life-form with a minimal biosynthetic capacity would require at least 250 genes.
So the first cellular life-form probably required 250 different kinds of proteins, in order to function. That’s still a pretty impressive number.
What proportion of amino acid sequences are functional?
The Evolution News and Views article refers to the recent article by Huang, Boyken, and Baker, before going on to cite the pioneering work of Intelligent Design researcher, Dr. Douglas Axe:
This paper is interesting because it relates to the work of Douglas Axe that resulted in a paper in the Journal of Molecular Biology in 2004. Axe answered questions about this paper earlier this year, and also mentioned it in his recent book Undeniable (p. 54). In the paper, Axe estimated the prevalence of sequences that could fold into a functional shape by random combinations. It was already known that the functional space was a small fraction of sequence space, but Axe put a number on it based on his experience with random changes to an enzyme. He estimated that one in 1074 sequences of 150 amino acids could fold and thereby perform some function — any function.
I’ll return to Dr. Axe’s estimate in a moment. The Evolution News and Views article went on to breathlessly declare that Axe’s figure of 1 in 1074 had actually been too generous, and that the true proportion of 150-aa sequences capable of performing a biological function was hundreds of orders of magnitude smaller (green bolding below is mine – VJT):
The new paper in Nature seems to point to a much smaller functional space. The authors say,
It is useful to begin by considering the fraction of protein sequence space that is occupied by naturally occurring proteins (Fig. 1a). The number of distinct sequences that are possible for a protein of typical length is 20200 sequences (because each of the protein’s 200 residues can be one of 20 amino acids), and the number of distinct proteins that are produced by extant organisms is on the order of 1012. Evidently, evolution has explored only a tiny region of the sequence space that is accessible to proteins.…
Since 20200 is about 10260, and the space actually sampled by living organisms is 1012, the numbers differ by at least 240 orders of magnitude for proteins of length 200, or about 183 orders of magnitude the 150-amino-acid chains Axe used. No wonder the authors say that “the natural evolutionary process has sampled only an infinitesimal subset” of sequence space.
This, I have to say, is a complete misreading of the paper in Nature by Huang, Boyken, and Baker. The authors are not trying to answer the question explored by Axe – namely, what proportion of 200-amino acid sequences are capable of performing a useful biological function? Rather, what they are estimating is the proportion of possible 200-amino acid sequences which are found in nature. Their answer is: 1012 divided by 20200 (which is approximately 10260), or in other words, 1 in 10248. But instead of concluding that any amino acid sequences which are not found in nature are non-functional, as the writer of the Evolution News and Views article appears to do, they draw the opposite conclusion: “The huge space that is unlikely to be sampled during evolution is the arena for de novo protein design.” In other words, there are a whole lot of new proteins out there which nature hasn’t created yet, but which scientists can create.
Back to Dr. Axe’s estimate of the proportion of 150-amino acid sequences which are capable of performing a biological function: I have previously discussed his figure of 1 in 1074 in my online review of his latest book, Undeniable: How Biology Confirms Our Intuition That Life Is Designed (New York: HarperOne, 2016). I quoted from various professors, including an expert in protein structure who argued that the proteins in the first living things would have all contained considerably less than 100 amino acids:
So I think the counterargument to the ID folks is not that sequence populations of 10E80 needed to be searched to find a 100-mer with robust enzyme activity, but rather that random populations of a few million relatively small proteins could contain a few molecules from which to start the evolutionary process.
Another professor whom I cited regarded Dr. Axe’s work as highly biased, because he had based his studies and calculations on very large sequences of amino acids (150-amino acid chains), even though much shorter sequences (such as polypeptides) were known to have biological functions.
Additionally, I quoted from a third professor, who kindly pointed out to me that because a very large number of different amino acid sequences were capable of performing the same biological function, the actual number of attempts that would be required to make a molecule with the same function as one of these proteins was likely to be much lower than 1060 or 1080. This professor also estimated that the number of attempts that would have been available to evolution had been estimated at 1042 – far greater than the number of attempts that could be made by doing man-made experiments (no more than 1012, which means that any protein which is too difficult for human experiments to generate might still be created by natural processes). This professor added that that while he was very sympathetic towards arguments against the natural origins of the first cell, and while he thought Dr. Axe may well be correct in arguing that abiogenesis was astronomically unlikely, in his opinion, Dr. Axe seemed to be trying to calculate the probability of an unknown process, and was therefore overstating his case.
Bottom line: we don’t really know how rare functional 150-amino-acid proteins are in sequence space, and we don’t know that they couldn’t have been derived from shorter proteins.
How did life get to be left-handed?
The Evolution News and Views article went on to say that there were
Axe’s estimate of one in 1074, one must note, referred to mutations to existing proteins in the universal proteome of all organisms. When considering random chains of amino acids in a primordial soup, however, Steve Meyer noted in Signature in the Cell (pp. 210-212) two other requirements. The amino acids must be one-handed, and they must form only peptide bonds. Applying generous probabilities of 0.5 for handedness and 0.5 for peptide bonds, Meyer reduced the probability for a lucky functional protein chain of 150 amino acids to one in 10164, far beyond the universal probability bound (p. 212). [Green bolding mine – VJT.]
The problem of life’s one-handedness which Dr. Meyer raises in his book is a genuine one: without homochirality, life would not exist.
A recent article by Denise Henry in Phys.org, titled, Discovery demystifies origin of life chirality phenomenon (March 11, 2015) describes a promising breakthrough in the field:
University of Akron A. Schulman Professor of Polymer Science Tianbo Liu has discovered that Mother Nature’s clear bias toward certain amino acids and sugars and against others isn’t accidental.
Liu explains that all life molecules are paired as left-handed and right-handed structures. In scientific terms, the phenomenon is called chirality…
Liu found that any molecules, if large enough (several nanometers) and with an electrical charge, will seek their own type with which to form large assemblies. This “self-recognition” of left-handed and right-handed molecule pairs is featured in the March 10, 2015, issue of Nature Communications.
“We show that homochirality, or the manner in which molecules select other like molecules to form larger assemblies, may not be as mysterious as we imagined,” Liu says.
In their paper, Liu et al. summarized their results as follows:
In summary, chiral macroanions demonstrate chiral recognition behaviour by forming homogeneous blackberry structure via long-range electrostatic interactions between the individual enantiomers in their racemic mixture solutions. Adding chiral co-anions suppresses the self-assembly of one enantiomer while maintaining the assembly of the other one. This leads to a natural chiral selection and chiral amplification process, indicating that some environmental preferences can lead to a complete chiral selection. The fact that the relatively simple inorganic macroions exhibit chiral recognition and selection during their assembly process indicates that the related features of biomacromolecules might be due to their macroionic nature via long-range electrostatic interactions
Another, more recent paper in Chemistry World by Dr. Rachel Brazil, titled, The origin of homochirality provides an excellent overview of the work in the field done to date, and discusses new findings. Dr. Brazil puts forward her own hypothesis.
Readers may still be wondering: why are the amino acids in a protein linked by peptide bonds, instead of non-peptide bonds? I’d like to invite any biologists who may be reading this post to weigh in on this subject.
What the ENV article got right
The Evolution News and Views article redeems itself at the very end, when quoting from the paper by Huang, Boyken, and Baker. The authors state:
Despite the advances in technology of the past 100 years, human-made machines cannot compete with the precision of function of proteins at the nanoscale and they cannot be produced by self-assembly.
The authors go on to suggest that the extreme efficiency of these nanoscale proteins is the due to the fact that “selective pressure operated on randomly arising variants of primordial proteins, and there were also hundreds of millions of years in which to get it right.” But this is pure speculation. As the author of the ENV article aptly puts it:
Now ponder that. They are duly impressed by the intricate molecular machines that proteins make in the cell, yet their worldview does not allow them to consider this as evidence for design.
Indeed.
What I am arguing in this post is that while I see no reason in principle why nature cannot generate proteins capable of performing useful biological functions, and while the mathematical arguments against such proteins originating by natural processes strike me as inconclusive, it seems to me perfectly reasonable to ask why the proteins we observe in nature are capable of technical feats which even our best scientists cannot match. It is not enough to simply invoke “hundreds of millions of years”: this is lazy scientific thinking, which makes no testable predictions. In the absence of such predictions, intelligent design of these nano-machines by a super-intellect sounds like a plausible explanation which warrants consideration.
Here’s one questions I’d like to ask the biologists: do the most efficient nanoscale molecular machines tend to be relatively short (as we’d expect if they arose naturally) or relatively long?
Readers who would like to know more about the difficulties attending abiogenesis are welcome to view Dr. James Tour’s online talk, “The Origin of Life – An Inside Story,” here or here. The take-home message of Dr. Tour’s talk was that currently, scientists know nothing about how the ingredients of life originated, let alone life itself. Dr. Tour makes no attempt to “sell” intelligent design to his audience: indeed, he formulates his argument without even mentioning it. Readers will find it highly watchable.
Right. My only hope in all of this is that you direct everyone you know to the discussions we have on Sandwalk and so on. You can ponder why that is.
Mung,
That seems gnomically to not-follow anything I said in the text of mine you quoted. In sum, quote-plus-response amounts to: “Modern life forms are not to be expected to retain representatives of every single primitive system, therefore eukaryotes first”.
Evolution has profound misconception about itself. Whenever an evolutionist is pressed, evolution turns out to be no evolution at all, only unspecified purposeless “change”. Actually, this has been so since Darwin, so no evolutionist needs to be pressed. In his Origin of Species he ended up doing away with species altogether. “It will be seen that I look at the term species, as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other, and that it does not essentially differ from the term variety, which is given to less distinct and more fluctuating forms. The term variety, again, in comparison with mere individual differences, is also applied arbitrarily, and for mere convenience sake.”
If evolution works so that there can be no rigor in using the word “species” as distinct from “variety” or whatever, then intermediate forms should be all over the place, at least in the fossil record, if not currently alive. Nobody has fixed this problem. Maybe you think there’s no problem here.
“There is no fundamental difference between man and animals in their ability to feel pleasure and pain, happiness, and misery.” – Charles Darwin
“The devil under form of Baboon is our grandfather.” – Charles Darwin
That is literally logically impossible, since evolution is not a thinking entity. It cannot hold misconceptions about anything.
Cool story bro.
That doesn’t look to me like he did away with it altogether, he simply explains that due to the nature of change over time, any application of it will be arbitrary.
I’m still waiting for these “miconceptions” evolution has about itself. That’s some curious stuff.
Why? Most organisms go exinct. Most as in almost all. That is the “cost” of the process. Random change filtered by selection yields death. When they die, they’re usually entirely consumed by other organisms.
There are plenty of transitional organisms in the fossil record. Whether you personally think there is enough is completely irrelevant, unless evolution is true there souldn’t be a single one at all. So the fact that there are dusins or even hundreds, even if you think there should be thousands, is still a problem for YOU, not for evolution.
There’s a HUGE problem there. Transitional forms exist when and where they should in the stratigraphic layers. Unless evolution is true, they shouldn’t.
I don’t see the relevance of these quotes at all.
hummm. let me think.
The more you feel humiliated, the more you have your *kick* ??!!
That must be it. I’m okay with you fantasizing about that 🙂
I assume that you mean the “thinking.”
Glen Davidson
how nice, Mikkel. I always thought you are a nice guy. Strongly deluded, but a nice guy…..
It may depend on your point of view, the removal of material to create a statue seems analogous to natural selection, we consider that a creative process.
Sure. Natural Selection is like an Intelligent Sculptor.
Natural selection (and other kinds of selection) doesn’t explain the origin of novel phenotypic features; it explains under what conditions novel phenotypes will tend to go to fixation in a population and under what conditions they won’t. But I’m not sure it matters whether we call that process “creative” or not. It’s surely nothing at all like human creativity.
1. Darwin means that he doesn’t not understand “species” as an Aristotelian kind. That’s the point of denying the species/variety distinction. That doesn’t mean that there’s no important concept of “species” for evolutionary theory. For more, see Species in the SEP.
2. How prevalent intermediate forms “should be” in the fossil record depends on the relationship between how rapidly speciation occurs, how often speciation occurs, and the likelihood of fossilization. Two words for you: punctuated equilibrium.
3. It’s recently been proposed that evo-devo and niche construction are the mechanisms that generate punctuated equilibrium as a pattern. (Oh, those damn scientists, always changing their theories in light of new data! Why can’t they just stick to their convictions no matter what the evidence is, like philosophers?)
The first sentence is either true or false depending on what exactly is meant by “fundamental”. Regardless, there’s ample evidence that there’s massive continuity between humans and other animals in terms of emotional or (if you prefer) affective capacities. It’s the cognitive abilities that are discontinuous.
Actually, I really like this remark from Darwin: “he who understands baboon would do more towards metaphysic than Locke”. And that indeed has been done: Baboon Metaphysics: The Evolution of a Social Mind.
Erik:
“Natural selection can preserve innovations, but it cannot create them. Nature’s many innovations—some uncannily perfect—call for natural principles that accelerate life’s ability to innovate.” – Andreas Wagner, Arrival of the Fittest
Natural selection, as stated, cannot create innovations. Nature and life apparently can. By what mechanism? And this is an evolutionist we are talking about, not an ID-ist.
——-
Eric, have you ever heard of a man called Charles Darwin? He was a nineteenth century naturalist and quite famous in his day. Perhaps you’ve read, “Voyage of the Beagle”? It’s a really good travelog and was a best seller in its day.
He also wrote some other books you may have heard of, perhaps in garbled form. “Origin of Species” was one of them. In it, Darwin attributed the plasticity of species to a combination of “variation” and “natural selection”. By variation, Darwin meant the commonly observed fact that offspring tend to resemble their parent(s), but not exactly. They vary in mostly subtle ways. They’ll be a little taller or a little shorter or their limbs will vary in length or their heads or feet or teeth or noses or whatever will be slightly differently shaped – in hundreds of different ways they will vary slightly from their parent(s).
We know today that these changes are caused by shuffling and combining two sets of DNA in the case of sexual reproduction and physically changing the DNA in both sexual and non-sexual reproduction. These physical changes include changing one or more base-pairs in the DNA or chopping out sections of DNA or adding new sections or other changes. Today we call such changes mutations
Darwin had no idea what caused variation because the very concepts of genetics and genes hadn’t been discoverd yet, let alone DNA, but he provided ample proof that it happened.
These “variations” are the source of the “innovations” you ask about. The new organisms possessing them are then tested by letting them try as best they can to survive and reproduce. If the new, say, tooth shape makes it harder to chew their food, they won’t do as well as their parent(s) did and they will tend to have fewer children of their own. The numbers of animals with that new tooth shape will tend to decrease and eventually go extinct.
On the other hand, if the new tooth shape lets them chew leaves to a finer pulp and extract more nutrients from each mouthfull than their parents, they will tend to do a little bit better at making a living and have a few more offspring than their parents did and animals with the new tooth shape will tend to increase in the population. This testing process is called natural selection.
So, the answer to your question is that variation creates the innovations and natural selection makes the useful innovations increase in the population. I hope this answers your question.
I must say that I’m puzzled by a couple of thjngs. First, Darwin’s principles of variation and natural selection are quite famous. I’m sure you’ve heard of them before. Second, they are the heart and soul of evolution. How in hell do you have the gall to challenge evolution if you’re that ignorant of its most basic claims? You remind me of the man who boasted that he was born to be a fantastically good Catholic because his father was a priest and his mother was a nun.
I also wonder if you’ve even read the book you’re quoting from. I have read it and I know that the statement you quote is part of the author’s setting up the problem and the rest of the book is devoted to explaining just how the innovations are found and brought into the genomes.
So I guess I wonder first, why you’re challenging a field of science you obviously know nothing about and second, did you even read the book you’re quoting at us?
🙂
davemullenix,
So, I see you have just graduated from Skeptic College. Do you do the full four year program, or just the online course part? I guess most of your course material came from Talkorigins?
Any plans to go back for a post grad degree? I think there you will dive deeper into Dawkins, and you can make some little computer models that spell things-should be cool. I would recommend you shore up your theory work a little more solidly before you do, just from what I have read so far. I know a lot of people do some of their thesis work on clay crystals becoming monkeys. Advanced stuff.
Slackers tend to just stick with the nuts and bolts; and not drift too far into the heady epigene stuff, and all. Way too much work. A lot of students just gloss over the sticky parts by writing about how “nature just does it” kind of thing…and leave it at that. Might be good for you.
This site has strict rules against outing. Read them and refrain from using any name or pseudonym other than that which the person chooses to use here.
More like a non intelligent sculpting mechanism.
I just love it when someone is condescending, and wrong.
The variations already exist in the population. A variation may be an innovation, but variations do not create themselves.
it does not explain the creation of individual features, but it can make those features distinctive by removal of transitions. The creation of a poodle from a wolf is result of both both genetics and artificial selection. Unwanted traits are selected against.
A carver does not create the wood, but through a process of artificial selection creates.
It’s not too bad a way of looking at things.
Still, I wouldn’t want to take it too far, because over time natural selection doesn’t just take away, it keeps additions which allow for more additions, hence fitness slopes, spanners, etc. Maybe natural selection is simply ripping away most of the new stuff, but there is new stuff appearing and not (always) being subtracted by the “sculpting” selection process.
Maybe it’s less of a marble or wood sculpture, and more of a changing topiary.
Glen Davidson
To be fair here my name is no secret, I go by the name Mikkel “Rumraket” Rasmussen on several forums and blogs (including Sandwalk) so it’s not like linking my online pseudonym to my actual name is that difficult 🙂
If you don’t object, there’s no rule violation. Thanks for clarifying.
Glen Davidson
Me neither ,just a rebuttal of the notion that natural selection cannot create
To reinforce Glen Davidson’s point, which I think is important, i.e.
which is to say that selection can be creative by altering the adaptive landscape, making some innovations advantageous that previously would not have been, and those in turn altering the landscape some more. As a good conceptual demonstration of how selection acting on random variation can gradually create a new feature, Nilsson & Pelger 1994 can hardly be beat.
Nilsson D., Pelger S. A pessimistic estimate of the time required for an eye to evolve. Proceedings of the Royal Society of London, Series B 1994; 256:53-58.
Is there a difference that makes a difference between saying that natural selection can “create” and saying that natural selection filters novel phenotypes such that the adaptive ones tend to go to fixation (all other things being equal) and non-adaptive ones tend to persist at extremely low levels (even if they are produced by dominant alleles) or disappear?
I ask because, given my interest in evo-devo and niche construction, the latter reading seems more accurate to me. But I certainly don’t want to say anything about evolutionary theory that’s false. Some correction here would be appreciated.
Patrick,
So you still haven’t gotten around to doing anything about Rumrakets post which was against the rules and you missed because you were too busy telling Otangelo to follow the rules Patrick?
Can you please now drop the charade of pretending you are a moderator here?
Kantian Naturalist,
How do you think an evo-devo system came to be KN? Did it happen by random mutations, or is it just one of those mystical things that nature can just do?
Whether natural selection creates would depend both on the scenario you imagine and on how you interpret the word. Above, I’ve given Nilsson & Pelger as a case in which I think selection should be viewed as creating.
Gould, in his brick, discussed your question as length, and decided that whether selection creates would depend on the sizes of the mutations. If one mutation produces a leg from a fin, with selection merely determining whether legs or fins spread through the population, that wouldn’t be creating. But if selection acts on many successive, slight variations, that would be.
I don’t think dominance, evo-devo, or niche construction have a lot to do with the question.
John,
Ain’t that the truth!
ETA: Almost 1500 pages.
Ah, I see. That make sense. It depends on how much work selection has to do in pushing organisms around on the fitness landscapes, vs a hopeful monster just being born there.
John Harshman,
When someone starts quoting Nilsson & Pelger as if what they have written about the eye is science, I know that person is not serious about understanding the problems of evolution theory.
Nilsson & Pelger first claimed to have made a computer program which models the development of an eye. Later they explained, well, we didn’t actually write the program (although they could have of course) but instead just explained the steps needed for the eye-you know, like poof a light sensitive patch appears. Next poof again, a concave depression appears precisely where the light sensitive patch also poofed to help it focus light. Poof, poof and poof again, the next steps all happening in exactly the right order, in exactly the places they need to be (all by random mind you), like a liquid membrane filling up the cavity, a lens forming, …
So in order to believe this whacked out fairytale of “random” mutations, we need to see these random mutations happening other places, so we can show just how random and sporadic they are. So we should see lots of creatures getting random mutations for strange depressions in their bodies, strange light sensitive patches, lens poofing out of nowhere on elbows, color sensitive cones, optic nerves sprouting up randomly in different body parts…
Nilsson & Pelger’s work is the absolute epitome of horrible evolution theory. It is a complete joke, and anyone quoting them is a pseudo-scientist.
Kantian Naturalist,
You response to him sounds like you have never thought of this before KN, is that the case?
The changes need to be small, but NOT TOO SMALL, so that they can have enough of an advantage without destroying the organism. Goldilocks mutations, that happen at just the right time, in just the right order, in just the right place on the body.
I realize your “nature can do it” theory helps to focus the mutations exactly where you want them (thus saving a lot of time), but this is not the theory John is going with. He is going with the, it happens completely on accident, but slowly works theory.
When you throw in your “nature just does” magic theory, then even Nilsson & Pelger can look like science.
Yup. And it isn’t just pushing around. It’s changing the landscape too. To pick a random example, once you can fly, it becomes advantageous to save weight by reducing the number of your ovaries, though not before.
Pure storytelling, John.
And according to this story, what is advantageous is not a consequence of selection, it’s a consequence of something else entirely. So selection’s not creating the landscape at all.
It is if the ability to fly was the result of selection, right? I am curious as to your explanation of how birds came to be able to fly and how (and why) female birds came to have just one functional ovary.
How birds came to fly is really irrelevant. You claim that they fly, and then it became an advantage to lose an ovary, or two, or three.
It’s story-telling John. There could be an advantage to having a non-functional ovary completely independent of flying.
What, really, is the difference between flying and swimming? Perhaps some fish have only one functional ovary too. Have you checked?
I shouldn’t have to tell you this. The difference between flying and swimming is that weight is very important in flight, not so much in swimming. We know that non-flying theropods had two ovaries (as did primitive vertebrates), while modern birds have one. Coincidence? I think not, and as I’ve mentioned there is a clear functional reason. You are free to present a different hypothesis, but I suspect you will not.
And the cause of the ability to fly is relevant to my original point, if not to yours.
John Harshman,
Poof, poof, poof…..Four ovaried, six legged birds competing with one ovaried, two legged ones. No contest!
John Harshman,
Minor point: actually, we don’t know if female theropods had one functional ovary or two. Rather, we know why one functional ovary is adaptive for birds. But it could be an exaptation from the theropod condition for all we know.
Congratulations! You’re at the same point as Darwin was. You realize that variations exist though, like him, you don’t seem to know where they come from.
Now work on the realization that if a variation makes it easier for its owner to make a living, and can be passed on to its offspring, it’s likely to become permanent in the population and you’ll understand the basics of evolution.
Phoodoo, thanks for giving me a chance to try out the ignore button. Well see how that works out.
Erik, I’m still wondering if you read that book you quoted at us.
Actually, we do know. The ovaries aren’t preserved as fossils, but the paired pattern of eggs in known theropod nests tells us they were laid two at a time, probably two per day until the clutch was completed. Contrast this with birds, which lay one egg per day.
Wow! I had no idea that information could be inferred from fossilized nests! That’s extremely cool! Thank you!
Answered in Moderation Issues, where this comment belongs.
I didn’t see the answer there.
Yes we can drop the charade, or no we must continue to maintain the charade?
What difference does it make? The book says what Erik quoted it as saying, and petrushka’s claim that it was just a book-jacket blurb and ought not be taken seriously was shown to be false.
Are the goalposts shifting now? I feel the goalposts shifting.
Weight, buoyancy, what’s the difference? Air and water are both fluids, don’t you know?
Air and Water: The Biology and Physics of Life’s Media
So why wouldn’t the same physical principles apply?
Look John, you made a bone-headed comment. Especially so given that you’re a professional. Admit it and let’s move on.
It’s a total mystery how any bird ever got off the ground! Why didn’t they just take up swimming? Smaller and lighter eggs would do the trick too!
And if birds ever discover Helium? Oh boy, watch out then!
I’m sure that’s a very nice book, and I’m pretty sure that if you read it you would find a number of important differences between air and water. It happens that buoyancy is quite important for aquatic animals, lift much less so. And lift (or the net difference between lift and weight) is quite important for flying animals, buoyancy almost negligible. My comment wasn’t the boneheaded one.
Sure it was.
How much does a non-functional ovary weigh? How much does a functional ovary weigh?
If Erik had read the book, he would know that it’s about where innovation comes from in evolution. The comment he quotes is in the beginning of the book and merely tells us that natural selection isn’t the source.
If Erik had actually read the book, then he would know that, in which case he would have to be either very stupid or very dishonest to throw that quote at us. He’d also have to be very ignorant not to realize that WE ALREADY KNOW THAT NATURAL SELECTION IS NOT THE SOURCE OF INNOVATION.
Now I personally don’t think that Erik ever read the book at all. I’m betting that he got that quote from another creationist, perhaps in a file entitled something like, “Fifty quotes FROM EVOLUTIONISTS THEMSELVES proving the impossibility of evolution!!!! (With verse and music.)”
So I’m asking Erik if he actually read the book because I’m curious to know if he’s dishonest and ignorant or ignorant and not too bright or maybe he has another explanation, perhaps something along the lines of, “The Devil made me do it!” (The Devil can quote scripture, you know, so he should be able to quote a regular book in order to embarass poor Erik and make ID look bad. This is my tentative explanation for O’Leary, by the way.)
The reason you’ve got that shifting feeling is because ID is built on sand.