All have been addressed elsewhere. may touch on a few over the weekend
Hi, Peter. I can begin to give some general response to a few of these, but youâll probably get better and more elaborate answers later on if others with more technical expertise drop in. I should at least be able to comment on a couple here.
which is related to âŠ
I would just note on the Cambrian âexplosionâ that in your phrase ârelative narrow windows of geological timeâ, âgeologicalâ is a key word. Iâm glad you included it and hope it wasnât lost on you. This âexplosionâ happened over millions of years. People do tend to forget that.
Regarding natural selection and information, that sounds suspiciously like one of the main assertions from Myersâ âSignature in the Cellâ book nearly 10 years ago now. Dennis Venema gave a review of that book which gives some more technical (at least to my level of thinking) response to this ânot enough new informationâ claim. It may still apply here too. In case you want something a little more accessible and recent, Loren Haarsma just did a 3-part series titled âCreating Information Naturally âŠâ which may interest you as well. If you were hoping for a shorter summary answer right here and now, Iâll defer you to others who come after since I would probably botch my articulation of it.
Thanks for bringing some of the specific quotes here. And I presume these are straight from the book you referenced? It might be good to confirm that too.
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Nonsense. This was an actual chance to falsify evolution/common descent. They donât actually tell you or write about how the vast majority of family trees were actually affirmed with only a few small changes but instead try to paint a lie right before your very eyes.
Natural selection doesnât produce any genetic information. If this is a quote from the book, then I would be very careful of reading it as it is just a wrong statement.
By narrow window you mean 20-30 million years?
Ridiculous but understandable from an ID book. Since they reject that any natural process can lead to any increase in âbiological informationâ (whatever that is would be anyoneâs guess) in the first place, it is no wonder that a 25 million year process is too little time.
No it doesnât. Ever hear of gene duplication? Tadaa! Happens all the time and you get a free pass to play around with all of those precious base pairs. Or we can even have whole genome duplications where you get millions of base pairs to play with. Again this is another misleading statement that is presumably from the book. It is just flat out wrong- a lie. To me, it indicates that whoever wrote this either is very ignorant of modern biology or is intentionally deceiving the readers.
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@EDC1 , not only what @pevaquark writes in his post, but whenever you read or see a treatment on embryonic development, it is the earliest phase that is the most generic.
Whales, for example, can be seen to develop buds which in other mammals would be hind legs. But the buds stop growing and are eventually re-absorbed into the embryo⊠because the coded instructions got interrupted at this point by some mutation, and the generic mammalian embryo is now arranging itself more and more like a whale!
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⊠so perhaps there is some conspiracy! Just not on the side they were originally thinking!
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IDâs claim that there are no good mutations is like my claiming that no one ever wins the state lottery because I have been buying tickets for decades and never won more than an occasional free ticket. I did win $92 once on a 5-number match, but thatâs a long way from a million.
Just because itâs worth repeating.
Alternatively, the only âsourcesâ the author consulted were previous ID books. For the most part, my impression is that the author is simply detailing his personal journey as a âconvertâ to ID, so he is reviewing the arguments he found persuasive. In short, nothing new here. Just a regurgitation of old news.
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We have done reviews of a sizable number of ID books over the years, and those reviews are easy to find with our search engine. Rather than try to critique every new piece of material put out by ID (and YEC and OEC and atheists and andâŠ), weâre most interested in providing a knowledge base that covers the common arguments put forth by those perspectives. If anyone feels that a key topic or issue is missing from our resource library, let me know.
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Peter,
Thank you for your inquiry and contribution.
While I have not read the book you refer to, the information does sound familiar. I do not think that that is a brave journey where no man has ever gone before. This is a journey which I have taken and I expect some others have too. It is the story of half a theory that is passing for a complete theory, however the mask comes off when we take the theory seriously.
As I used to repeat unto I hope that everyone understood, Darwinâs Theory had 2 basic fundamental aspects, Variation concerning how genetic changes occur, and Natural Selection concerning how genetic changes are selected in or out. The problem is that the science of evolution has concentrated on Variation or genetics and not on how Natural Selection works (which is different from what Darwin and Dawkins think.
Therefore Darwinian evolution is half a theory about genetics which is good, but not how evolutionary change works. This is how so many people are fooled, because it half works so they assume it fully works, when it does not. I try to explain all this on my book, Darwinâs Myth.
The good news is that I also explain how Natural Selection really works so that evolution can be good science. ID points to the problem of Darwinâs Myth. I point to the solution of Darwinâs Myth. Myth refers to a belief, which is based on authority and is not supported by rational thinking and verified experience.
Years ago, I met @Paul_Nelson at a conference in Texas where he, Stephen Meyer, Doug Axe and others were presenting the ID view. I was pretty much an unknown in the conversation at that point, as I was just getting my feet wet.
I sat in on a presentation that Meyer gave where Paul also contributed. Paul spoke about genes involved in early development in Drosophila. Since my PhD is in Drosophila genetics, naturally this was familiar territory. After all, the work under discussion was not only fly work, but it was Nobel-winning work done by giants in the field (Christiane Nusslein-Volhard and Eric Wieschaus).
I was very surprised by Paulâs portion of the talk, because he expressed the sentiment exactly as you have quoted from that book (and that Iâve requoted above). Nelson presented Nusslein-Volhard and Wieschausâs work as evidence that all mutations in early developmental genes would be lethals.
This is of course nonsense. There is non-lethal variation in these genes in populations. The reason that Nusslein-Volhard and Wieschaus were dealing with lethal mutations was - wait for it - they started the experiment by specially screening for lethal mutations in order to find important developmental genes. In other words, of course they would only find lethals! Thatâs the only thing they were looking for!
I thought that Nelson just didnât know this, and I didnât want to embarrass him, so I waited until after the talk and I told him privately (with Meyer standing next to him listening to our conversation). I was aghast - Nelson told me that he did indeed know that, but that it wasnât relevant to the talk. I thought this was very misleading.
I was also disappointed to see the same line taken by Nelson and Meyer in chapter 13 of Darwinâs Doubt, where the same arguments are presented. I strongly suspect that this new book is drawing on Meyer and Nelson for this. But Meyer and Nelson are misleading here.
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If the author of Heretic (originally published 4 years ago) is comparing Intelligent Design to ârandom Godless Evolutionâ - - how relevant could the book be to us here who are volunteer supporters of BioLogos?
Surely youâve read the BioLogos mission statements regarding the promotion of a new understanding of Evolution, combined with Christian Faith, yes?
God uses natural operations of mutation, natural selection and speciation to create the miracles of life we find all over the Earth.
The book Heretic doesnât seem to acknowledge that there is a way to be a Christian and to combine that with a profession in Science.
I also think its safe to say that early mutations in development werenât as inflexible back around the Cambrian as well.
i donât have my copy of Darwinâs Doubt handy. Does Meyer cite Christiane Nusslein-Volhard and Eric Wieschaus in chapter 13?
I think you will find that the linked article does a nice job showing how just one new gene can create opportunities for all following generations! [ By the way⊠isnât that art work kind of mind-blowing!? ]
Scientists are on the verge of answering the age old question of why speciation went into over-drive during the Cambrian Epoch!
It turns out that the genetic processes that allow DNA to remain relatively dormant (or in other words, âun-triggeredâ into any of hundreds of possible and quite specific outcomes) do not do well in a highly oxygenated environment. So as single celled life, like algae, started to produce an increasingly oxygen-rich atmosphere, it began to define just where life could survive.
[ Imagine if you were a one celled creature ⊠and all of a sudden your replication systems just started firing all over, randomly, because they are triggered by too much oxygen???]
Imagine being a proto-amoeba drifting into a pocket of highly oxygenated water. Suddenly, your DNA starts to fire off sequences triggered by the random encounters of oxygen molecules accumulating within the cell itself. Proteins you need are not being made, because amino acids are being hi-jacked to make proteins you donât need. Sure, a robust living cell can survive low levels of these kinds of mis-fires ⊠but at a certain point, the cell expires when the internal chaos exceeds some threshold.
Enter stage right⊠âHypoxia-Inducible Factorsâ, specifically a âproto-HIF - 1aâ, the simplest protein that responds to Oxygen, and by regulating genetic transcription, protects cells from over-reacting to higher levels of oxygen diffusing into the cell from the environment.
HIFs - A new Way of Living
âIt behaves as a metabolic switch that allows cells to âenter or exit a low-oxygen consumption mode,â she said, so it would have allowed emerging animals to be less sensitive to oxygen fluctuations in their environments.â
âOrganisms could start to manage stem cells better,â Hammarlund explained. Their tissues could grow with fewer oxygen-imposed constraints, so they could be made of more diverse cells growing in more varied structures. Moreover, the animals could begin to populate more habitats with varying oxygen levels."
Pre-Cambrian Life Fades Out as Planetary Oxygen Levels Rise
âHammarlund wonders whether the Ediacaran creatures, which disappeared at the start of the Cambrian, lacked this ability and therefore lived in the deep parts of the ocean because oxygen concentrations were more stable there.â
Thereâs Power in that Oxygen!
â. . . the development of the HIF proteins presented the âproper key to get at the gold mine,â Hammarlund said. It wasnât until HIF came along ⊠[and soon the more refined HIF-1a found in present-day invertebrates] ⊠that animals could start to use oxygen for more metabolic energy, build more elaborate tissues and cope better with oxygen damage. âThe HIFs probably werenât the only key, but theyâre one we now know,â she said.â
Vertebrate Life Doubles-Down on Oxygen: HIF-2a
"As support for her theory, Hammarlund points to the evolutionary history of HIFs in animals. HIF evolved in animals, and it can be found in nearly all animal species; meanwhile, HIF-2α is unique to the vertebrates. âIt makes sense when you think about it,â she said. âVertebrates are bigger and have longer life spans than invertebrates. Theyâre better at maintaining their tissues in oxygenated environments.â
âWhen HIF-2α entered the picture, it would have given vertebrates even greater flexibility because their tissues could behave as though they were hypoxic regardless of their environment. This would have enabled them to form complex organs from diverse, highly specialized cells without regard for disruptive oxygen exposure. âHIF-2α was an even better tool for sustaining . . . pockets of hypoxic [high-oxygen] responses,â Hammarlund said. Stem cells could have resided in regions that were completely isolated from the oxygen gradients throughout the rest of a tissue.â
Invertebrates Limpet Along
âIn contrast, she said, many invertebrates such as insects spend most of their lives as larvae living in low-oxygen conditions, and they canât regenerate tissues as vertebrates can. Hammarlund thinks that invertebrates may not be as good as vertebrates at maintaining viable stem cells in their adult tissues for regeneration.â
Itâs All a Coincidence?
âPeople who live at extremely high altitudes on the Tibetan plateau, for example, possess a mutation in a gene that encodes HIF-2α, causing the protein to function less effectively. That mutation also protects Tibetans from the otherwise detrimental health effects of living at lower oxygen levels, including altitude sickness, increased risk of stroke and pregnancy complications.â Is it just an accident that ââŠthe HIF-2α phenotype is less necessary at high altitudesâ where oxygen levels are always depleted, Hammarlund said.â
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Yep, a few hundred million years of building around a certain way of doing things will do that to a lineage.
Yes. A discussion of their work is the opening part of the chapter. Their pictures are even featured.
What was their argument that it wasnât relevant? I do not understand. I guess it was just that they didnât have a study to review on that type that didnât deal with nonlethal mutations. I agree that it is misleading.
Iâd welcome seeing some examples. Recall that the issue here is relevant variation, namely, âearly acting mutations of global effect on animal developmentâ (Darwinâs Doubt, p. 262). Data from Drosophila would be especially welcome â instances of variation in bicoid or nanos, for example, where fly adult morphologies are viably and heritably modified at large scale.
If you have Darwinâs Doubt handy, take a look at Eric Wieschausâs reply to this question, when it was put to him at the 1982 AAAS meeting (pp. 256-7), shortly after his breakthrough Nature papers with Nusslein-Volhard. Most evolutionary biologists who work on this puzzle say that the depth and type of variation required for macroevolution (e.g., as seen in the Cambrian Explosion) no longer occurs, as metazoan ontogenies have now âhardenedâ around their central control elements. This was the late Eric Davidsonâs view, and that currently also of paleontologist Douglas Erwin at the Smithsonian.
Knock an embryo off its normal developmental trajectory, and it doesnât know where to go (so to speak). This is the unmistakable signal from the model systems of evo-devo, starting with Drosophila.
I have very little formal training in science but am currently reading Kenneth R. Millerâs book Human Instinct. I especially enjoyed reading the early chapter on how communities of single celled organisms became multi-celled animals.
It seems to me that at this juncture in history is when we would expect to find the greatest variety of body plans emerge. When the capacities of the single celled organisms were ripe for inclusion in multi-cellular arrangements it seems to me that is when you would find the greatest number of permutations. But Iâm not sure if this occurrence coincided with the Cambrian explosion or not. Can anyone tell me if I am barking up the wrong tree here?
Why does it have to be at a large scale in order to be relevant?
If youâre suggesting that only mutations of large effect are relevant, then sure, youâre not likely to find any that are not problematic. But that is begging the question, it seems to me. Youâre excluding, from the get-go, the possibility of incremental changes.
Pick an isoform of bicoid (for example), look at the mRNA sequence for it, and run a BLAST. Youâll see variation - small amounts within populations (if there are variants in the database) and larger amounts across the various species of Drosophila. Youâll also notice that the differences are roughly proportional to the overall percent identities of the genomes compared - i.e. fly species that are recently diverged have very similar isoforms (95%+ identical) but more divergent species have less identity.
Are you proposing that all of those copies of bicoid are not orthologs, but were independently created? And if they can vary somewhat, what is to stop them from shifting their average characteristics over time within a population?
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Because the question at hand is the macroevolution of animal anatomy, which occurs â if it does â at large scales. The variants in bicoid that you describe are real; major differences in their functional roles (A-P patterning cascade), however, are not.
True story: in southern China, in June 1999, Eric Davidson and I discussed this very question. I told him about my interactions at evo-devo meetings where no one (really, nobody) could give me examples from their model systems of heritable large-scale variation in early embryos. He snorted and replied that one could have up to six copies (paralogs) of bicoid in flies, and the flies developed just fine.
I then asked him what the flies looked like.
Wild-type Drosophila, he answered.