Uncommon Descent Serving The Intelligent Design Community

Multicellulars arose by “long slow dance”?

arroba Email
possible evolutionary transitions/ Dey et al./Trends in Cell Biology 2016

From ScienceDaily:

Although scientists generally agree that eukaryotes can trace their ancestry to a merger between archaea and bacteria, there’s been considerable disagreement about what the first eukaryote and its immediate ancestors must have looked like. As Thattai and his colleagues Buzz Baum and Gautam Dey of University College London explain in their paper, that uncertainty has stemmed in large part from the lack of known intermediates that bridge the gap in size and complexity between prokaryotic precursors and eukaryotes. As a result, they say, the origin of the first eukaryotic cell has remained “one of the most enduring mysteries in modern biology.”

That began to change last year with the discovery of DNA sequences for an organism that no one has ever actually seen living near a deep-sea vent on the ocean floor. The genome of the archaeon known as Lokiarchaeum (‘Loki’ for short) contains more “eukaryotic signature proteins” (ESPs) than any other prokaryote. Importantly, among those ESPs are proteins (small Ras/Arf-type GTPases) critical for eukaryotes’ ability to direct traffic amongst all those intercellular compartments.

The authors consider the available data to explore an essential question: what might the archaeal ancestor of all eukaryotes look like? “If we could turn back the clock and peer inside this cell, would its cellular organization have been like that of an archaeal cell or more eukaryote-like?” Dey says.

As the closest known archaeal relative of eukaryotes, Loki helps to answer that question. The researchers say that the ESPs found in Loki are unlikely to work in the same way they do in eukarytoes. That’s because Loki doesn’t appear to have enzymes required for ESP association with membranes or key building blocks of the membrane trafficking machinery. Paper. (public access) – Dey et al. On the archaeal origins of eukaryotes. Trends in Cell Biology, 2016 DOI: 10.1016/j.tcb.2016.03.009 More.

Let’s test drive this theory in a real life situation with no intelligent intervention at all. See what happens.

See also: Magnetism enabled multicellular life

Maybe if we throw enough models at the origin of life… some of them will stick?


With Enceladus the toast of the solar system, here’s a wrap-up of the origin-of-life problem

Follow UD News at Twitter!

However, in this world, many folks accept anything for an explanation. Even if it doesn’t explain much. To make things even worse, serious deep thinking about challenging issues is not a common practice these days.
Very true because if they did we would have nothing to argue about :-) bill cole
There yet? :)
[...] additional study will be needed to clarify whether candidate genes identified in this study are indeed targets of selection and the extent to which they play an important role in the biology of early-diverging symbiotic metazoans. Further experimental study focused on candidate loci reported here could provide additional insight into fundamental cellular processes in early-diverging symbiotic metazoans.
Genome-wide polymorphism and signatures of selection in the symbiotic sea anemone Aiptasia Emily S. Bellis, Dana K. Howe and Dee R. Denver BMC Genomics 2016 17:160 DOI: 10.1186/s12864-016-2488-6
bill cole Yes, that's a good point. However, in this world, many folks accept anything for an explanation. Even if it doesn't explain much. To make things even worse, serious deep thinking about challenging issues is not a common practice these days. Many necessary questions are avoided or not asked. Concepts and ideas are not put to test. The quality of human communication is bizarre. Carefully listening is not a common practice. Attentive, active, reflective listening are not natural skills. We should make the commitment to do it. But that kind of commitment doesn't come naturally either. The whole picture isn't encouraging at all. Can it be corrected? How? Dionisio
Dionisio The origin of the first eukaryotic cell rivals and perhaps surpasses the origin of life as an event that is difficult to explain through blind unguided processes. -the nuclear pore complex -chromosomes and their structure -the spliceosome -the modern ribosome structure -the golgi complex bill cole
The interesting discussions about genes, proteins, ncRNA, or other important players in the immense biology show, could be compared -though not so accurately- to a situation where one is trying to understand how cars are made and how they work, but is getting stuck on and not moving past the heated discussion about how to make rubber in order to manufacture the tires and with modifications also produce the insulation for the electric circuit wires. :) Dionisio
Here's the conclusion of this 4-year old paper:
[...] what seems clear is that the evolutionary history of the FGF gene family required numerous events of gene duplication and gene loss at different times and in different evolutionary lineages. The next question we should address in the near future is which are the implications of this complicated evolutionary history of the FGF gene family on the functional evolution of this signal and in the morphological evolution of metazoans.
Evolution of the FGF Gene Family Silvan Oulion, Stephanie Bertrand, and Hector Escriva International Journal of Evolutionary Biology Volume 2012 (2012), Article ID 298147, 12 pages http://dx.doi.org/10.1155/2012/298147 http://www.hindawi.com/journals/ijeb/2012/298147/
Once they finish elucidating all that, they might want to figure out the evo-devo "delta dev" conundrum in terms of developmental procedures including regulatory networks, signaling pathways, etc.: Dev(d1) = Dev(ca) + Delta(d1) Dev(d2) = Dev(ca) + Delta(d2) Since in some cases Dev(ca) might not be fully known, it could be reconstructed (approximately) by finding the differences between Dev(d1) and Dev(d2) -assuming they are well understood in most details. Thus the common procedures seen active in both Dev(d1) and Dev(d2) most probably were in Dev(ca). The procedures that are unique in either Dev(d1) or Dev(d2) might or might not have been in Dev(ca). But ideally, if all Dev(ca), Dev(d1), Dev(d2) are well understood, then determining Delta(d1) and Delta(d2) shouldn't be that difficult. There yet? :) Dionisio
#5 correction Sorry, I apologize for any misunderstanding caused by two spelling errors @5 The third line should read: "These guys paid dearly for their unacceptable error: they used the dreaded 'm' word..." Dionisio
Mung Do you still remember this scandal? These gays paid dearly for their unacceptable error: thy used the dreaded 'm' word. Actually, they made it even worse by using worse unacceptable words. Next time they should exercise caution when choosing words for their papers. :)
Biomechanical Characteristics of Hand Coordination in Grasping Activities of Daily Living The explicit functional link indicates that the biomechanical characteristic of tendinous connective architecture between muscles and articulations is the proper design by the Creator to perform a multitude of daily tasks in a comfortable way. Hand coordination should indicate the mystery of the Creator’s invention. In conclusion, our study can improve the understanding of the human hand and confirm that the mechanical architecture is the proper design by the Creator for dexterous performance of numerous functions following the evolutionary remodeling of the ancestral hand for millions of years.
Biomechanical Characteristics of Hand Coordination in Grasping Activities of Daily Living Ming-Jin Liu, Cai-Hua Xiong, Le Xiong, Xiao-Lin Huang PLOS Published: January 5, 2016 DOI: 10.1371/journal.pone.0146193 http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0146193
“I believe that a scientist looking at nonscientific problems is just as dumb as the next guy — and when he talks about a nonscientific matter, he will sound as naïve as anyone untrained in the matter.” “The same thrill, the same awe and mystery, comes again and again when we look at any question deeply enough. With more knowledge comes a deeper, more wonderful mystery, luring one on to penetrate deeper still. Never concerned that the answer may prove disappointing, with pleasure and confidence we turn over each new stone to find unimagined strangeness leading on to more wonderful questions and mysteries – certainly a grand adventure!” “The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn’t know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty darn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty – some most unsure, some nearly sure, but none absolutely certain.” “Through all ages of our past, people have tried to fathom the meaning of life.” “What, then, is the meaning of it all? What can we say to dispel the mystery of existence? If we take everything into account – not only what the ancients knew, but all of what we know today that they didn’t know – then I think we must frankly admit that we do not know.” “It is our responsibility as scientists, knowing the great progress which comes from a satisfactory philosophy of ignorance, the great progress which is the fruit of freedom of thought, to proclaim the value of this freedom; to teach how doubt is not to be feared but welcomed and discussed; and to demand this freedom as our duty to all coming generations.”
?Richard Feynman US educator & physicist (1918 – 1988) The Value of Science (1955) http://www.math.ucla.edu/~mwilliams/pdf/feynman.pdf
Did anybody say mystery? :) Dionisio
Mung Those folks you typically encounter are correct. The association of that word with biology seems like an invention of this blog. Here's an example: https://uncommondesc.wpengine.com/intelligent-design/mystery-at-the-heart-of-life/ No serious scientific papers would use such a word. Science desk with facts, not fiction. :) Dionisio
Does that mean the given proteins were available and conserved long before they were needed and used? Cool! This reminds me of a time when we released programs that contained features for future releases, but the users didn’t know they were in there already. Or programs that contained features that were available to certain users under particular conditions but were invisible to the rest. Sometimes the new features were physically included, but officially unavailable until other conditions were met. Once the conditions were met, a simple procedure could activate the otherwise hidden functionality. Some features were included for the same developers to use them during testing. Who would have thought that such methodology had been implemented long before we did? However, we can't forget that computer programs are just a bunch of tiny electrical impulses wildly dancing around. :) Dionisio
As a result, they say, the origin of the first eukaryotic cell has remained “one of the most enduring mysteries in modern biology.”
The atheists I typically encounter deny that there's any mystery at all. Mung

Leave a Reply