Some present may remember an entertaining (not to mention illuminating (pun intended) ) blog by Professor Larry Moran:
http://sandwalk.blogspot.ca/2016/04/fun-and-games-with-otangelo-grasso.html
I am a high school Biology teacher and Professor Moran threw out some challenges which cut me to the quick.
Here is a very brief and incomplete summary:
The dual photosystems of Blue-Green Algae clearly evolved late from a combination of a type I reaction center in species like Heliobacter and green sulfur bacteria and a type II reaction center from species like purple bacteria and green filamentous bacteria. The oxygen evolving complex was a late addition.
Both photosystems employ Porphyrins and Carotenoids which are important in various metabolic processes (not just photosynthesis) meaning their evolutionary history may reflect many other functions only to be co-opted later for photosynthesis. Meanwhile both can be demonstrated to have abiogenic origins.
Meanwhile RuBisCO is found in non-photosynthetic species…
According to Professor Moran, many misconceptions are perpetuated when teaching according to textbook orthodoxy. Instead we should consider Photoreduction and Photophosphorylation as two stand-alone processes, and that the capture of light energy to produce carbohydrates is a highly specialized phenomenon; which, from an evolutionary point of view is not really (at least not originally) part of “photosynthesis” (i.e. carbohydrate anabolism).
Even Flowering Plants not only can, but in fact most of the time do, decouple ATP/NADPH production from Carbon fixation. Indeed, much of the ATP & NADPH generated by Photosystems II & I respectively are in fact redirected to immediate energy needs, even in flowering plants.
Meanwhile, I heartily agree with Larry Moran’s thesis that it is important (nay, let’s say instead imperative) to teach students that there’s more to life than just flowering plants and humans?
Larry Moran (in very unsubtle and less than gentle terms) “suggests” such strategies should apply to teaching of all biochemistry; i.e. from simple pathways to more complex pathways.
A recent “must-read” article inspired me to respond to Larry Moran’s challenge,
https://www.nature.com/articles/ncomms13924.pdf
… and I have cobbled together a worksheet, where I attempt to prove that photosynthesis is
1 – misunderstood (tis not really about Glucose and it’s not even about the Calvin Cycle) at least from a Biochemist’s evolutionary POV. Ecologists have justification to differ.
2 – NOT “irreducibly complex” but rather a hodge-podge cobbling by evolution over a long period of time. (cf https://embryo.asu.edu/pages/evolution-and-tinkering-1977-francois-jacob)
Larry Moran’s fingerprints are all over this work of mine, for which I really cannot claim any originality on my part.
I would be grateful for any constructive input and suggestions for improvement. Remember, the intended target audience remains high school students.
Thanks in advance and best regards,
Here it is:
https://drive.google.com/file/d/0By6ZKSkkTEG-QXFtWVhKOWNwREE/view
Bill,
Before you change the subject, do you finally accept that when Behe says “Common descent is true”, he means that common descent is true?
Or are you going to come up with another Billsplanation, like “He doesn’t mean it’s true true — he’s just saying we can’t rule it out”, or some other hogwash?
Rumraket,
Do you think Mike believes that it is just reproduction over many generations? Do you think Mung believes that? How do you think these guys integrate ID into their belief that common descent is true?
The notion of endosymbiosis
As Larry Moran eloquently elucidated on frequent occasion: the distinction between host and symbionts remains rather arbitrary and capricious
Review my OP
The dual photosystems of Blue-Green Algae clearly evolved late from a combination of a type I reaction center in species like Heliobacter and green sulfur bacteria and a type II reaction center from species like purple bacteria and green filamentous bacteria. The oxygen evolving complex was a late addition.
So I ask my students: how can the evolution of such cooperation even begin to happen?
That is the thrust of my worksheet: intercellular syntrophy between two Litotrophs enabling each other’s independence from an inorganic substrate can eventually lead to intracellular endosymbiosis where one biological system acts as an electron donor and the other as an electron acceptor within one cell
Yet again your challenges have proven useful! I will follow up on your recommendations and continue in similar vein with Cyanobacteria evolution. Thank you, yet again you are my Muse!
Do we agree that even if a case for Irreducible Complexity can be suggested, any such IC is in fact “evolvable”, even in Cyanobacteria which is really a “Jonny-come-lately” in the history of evolution?
Otangelo Grasso for one, you as well apparently considering your indignant outbursts citing Cyanobacteria
Please reread the original OP which cites
http://sandwalk.blogspot.ca/2016/04/fun-and-games-with-otangelo-grasso.html
Cyanobacteria are way way later developments in this evolutionary story and as a result, inappropriate to consider as starting points in how far more ancient Lithotrophs mutually enabled each other’s independence from inorganic substrates for biological redox reactions’
I must thank the agent provocateur who posted the following:
Evolution as a Ralph’s Supermarket
Uncommon Descent
November 11, 2017 at 6:13 pm
[…] at the The Skeptical Zone there’s a reference to a post from Larry Moran’s blogsite. The question of irreducible […]
https://uncommondescent.com/intelligent-design/evolution-as-a-ralphs-supermarket/
Where Mung opines:
Mung
Reminds me of how Walter ReMine refers to evolutionary theory as a smorgasbord.
At last! Some unambiguous clarification exactly why Mung takes exception to my worksheet!
He would prefer to dwell on how miraculously complex Cyanobacteria appear as irreducibly complex and unevolvable and not be distracted by simpler and easier scenarios to behold (syntophic Lithotrophs mutually assisting each others’ independence from inorganic substrates) which are occurring even as we speak
NowI understand his chagrin
Again, Bill:
Before you change the subject, do you finally accept that when Behe says “Common descent is true”, he means that common descent is true?
Yes, Mike believes there is common descent through reproduction over many generations.
He also believes that along this process, God comes down from heaven in order to *POOF* things like the flagellum, and portions of the vertebrate immune systems, into existince in a puff of smoke.
I have no idea what Mung believes about common descent. But why don’t you just ask him instead of me?
God leaves out the puff of smoke unless someone is actually watching.
Rumraket,
Exactly, with the possible exception that the flagellum may be part of the original design of the bacteria. Also he believes that the causation may be front loaded into unfolding of the universe.
Given this why is it so important to keiths that Behe concedes common descent given his version is so different from Darwins. Just a rhetorical question 🙂
Thank You Mung!
I owe you big time!
Here is a rough copy of efforts I will share with the Biology Teaching Community
I would appreciate if any present could offer corrections or suggestions for improvement
Again – Mung – I thank you!
https://drive.google.com/open?id=17ieGFlXA-Pb2b2jwVwEuN043oKtlG3lg
Bill,
We’re laughing at you because of your panicked reaction to learning that Behe accepts common descent, and your lingering inability to come to grips with it. It’s fantastic entertainment!
And yes, Behe accepts common descent — the belief that life on earth is related by common ancestry — just like Darwin himself did:
Behe thinks that you’re wrong, and Darwin is correct, about common descent.
He also thinks that you’re wrong, and Darwin is correct, that we share a common ancestor with chimpanzees.
Put that in your pipe and smoke it.
And please share your panicked reaction so we can laugh some more.
Keiths
I owe you a preemptive apology
Only after hitting send did it occur to me that I again conflated IC with unevolvability
I seem to make that slip frequently because those detractors who do not seem to understand Behe, make the same conflation
This is a draft
I see other corrections are needed
I would appreciate any suggestions on your part
Thanks in advance
Instead of teaching biology to kids, maybe you could open up your own church?
That seems to be more of your interest.
I do not understand. Church?
Well, at least then when you are preaching its tax deductible.
Preaching? Listing acumulated scientific observation is “preaching”?
Out of curiosity: you think Galileo was treated fairly? Was he preaching?
TomMueller,
Um, yea, right.
Amen brother!
I missed this gem from Rumraket. The functioning parts of chloroquine resistance are the mutations in the protein coding genes.
Yippee, we no longer have to be stuck with using English in this thread, we can make up any meanings we want. What freedom!
I think Behe’s belief is even stronger than Darwin’s.
Happy to be of service. 🙂
Remarkable Coincidences in Photosynthesis
Warning: Disco-Toot bullshit content above
I want to thank participants for their insightful suggestions… yes that includes you Sal. I even included your frog metaphor.
Special thanks goes to Mung and to Bill
A deep bow and tip of the hat goes to Keiths.
Here is a rewrite:
https://drive.google.com/open?id=1vh1iQvsxx5abEwqsAYvOeD8GLFV1Tc2D