Thursday, December 14, 2017
The “eureka!” moment, when I saw the Pogonophora as the significant link of the two main divisions of higher animals, can be credited to the stimulation of reading Gans and Northcutt, 1983.
Gans, Carl, and R. Glenn Northcutt. 1983. Neural crest and the origin of vertebrates: a new head. Science, 220:268-274.
They placed the pogonophorans in line with the vertebrates based on development. I was sure the evidence was overwhelming that pogonophorans were close to, or one of, the annelids. But I also realized most scientists are honorable and truthful in their work and deserve to be taken seriously. But how could Gans & Northcutt be right when the overwhelming evidence indicated pogonophorans were close to annelids and other protostomes? Somehow, in an instant, I realized it could be true if pogonophorans were a connecting link. A deluge of such evidence came to mind. And, as I followed new, as well as some older, molecular and other evidence the connection became well supported.
Engemann, Joseph G. 1968. Pogonophora: the oldest living animals? Pap.
Acad. Sci., Arts, and Letters,
Engemann, J. G. 1983. Coelomate animals are monophyletic. American Zoologist, 23(4):1008. Abstract # 753. The Pogonophora have characteristics of both protostomes and deuterostomes and provide support for the annelid theory of origin of deuterostomes.
Understanding the extreme age of individual pogonophorans, suggested in the 1968 report above, was a result of preparing a new section on pogonophorans for the 1968 edition of Hegner and Engemann’s Invertebrate Zoology text. It was reprinted in chapter 14 of the 1981 edition (Engemann and Hegner) which discussed the evidence making it very likely deep-sea animals typically have very extended lives and low respiratory rates. My 1983 abstract noted above was reported shortly after Gans and Northcutt triggered my conclusion with their evidence.
A full report of the paper was submitted to Nature. The reviewers did not reject the paper but the editor decided not to publish it because it was not of wide enough interest. I had given it a title suggesting pogonophorans were the protostome-deuterostome link. He was not moved by my suggestion that a catchier title would have been “my ancestors were worms”.
Of course, there is a whole sequence of organisms from protozoans through sponges, jellyfish, flatworms, fish, amphibians, reptiles, insectivores, primates and closer relatives in our direct lineage. But we don’t have direct ancestry through either nematodes, mollusks, arthropods, echinoderms, or many other groups. If people squirm to think some ape-like primate was in our evolutionary ancestry, how much more appropriate to squirm for a worm.
What about extreme longevity of pogonophorans?
It helps explain their slow evolutioary rate, and thus, their close molecular relationship to diverse groups of animals.
What is so important about abyssal life of pogonophorans?
The slow pace of life at great depths, due to great pressure, low food and oxygen input to the depths, paucity of life, probable absorption of fossil nutrients from sediments, and isolation from many surface extinction factors makes them living "fossil" ancestors. [Note: really old people may live to see great, great, great grand-children]
What has pressure to do with it?
It has not been demonstrated but it is obvious that reduced diffusion based metabolism is probably the missing factor in reduced community respiration noted at great depths. I await someone making observations of reduced Brownian movement and/or diffusion of dyes at great depths. It may be a factor in extended submersion time for deep-diving whales. Water is ever so slightly compressed at great pressures- it may be the cause.
Could circulatory systems increase activity and decease longevity at great depths?
Perhaps. But whales presumably shut down some less essential portions of theirs.
What about the great difference in early embryology of the groups alleged to be connected by the pogonoporans?
That has been discussed in other posts. Also, observation of isopod development in Tasmania and Michigan gives some clues to different rates of development associated with ecological factors. Abyssal life put a species survival premium on shifting from protostome to deuterostome development.
Joseph G. Engemann Emeritus Professor of Biology, Western Michigan University, Kalamazoo, Michigan December 14, 2017
Monday, December 11, 2017
If you find anything I’ve written inspirational and/or of value, the credit goes to God. I have been somewhat reluctant to extend that credit until recently for two reasons. One, it sounded too boastful to think God had so favored me, and there are some scriptural passages that discourage excessive self-praise or taking the best seat. And my mother had a frequent admonition that said “self-praise stinks”. And two, I may have had self-doubts, but primarily the role God has had in my life was somewhat obscured in my mind until old habits had been well-established.
I do not know what made me so curious about things. It might be that the early arguments with my brother helped me see that ideas I could not clearly express were as valid as his well-reasoned opinions. The possibility that we were both wrong did not occur to me then; but sometimes, then or later, I came to the realization that we both may have been right in a limited way. The consequence to me was that my thinking process may have been slowed down by applying too many “what ifs” to the subject at hand.
Applying alternative views when reading science research reports made me realize scientists often abandon old views prematurely when their research shows a statistically significant support for their hypothesis. Perhaps individuals do the same thing when they understand exercise is good for their health and think they can exercise more and go back to smoking, or pigging out on sweets, or any other favorite vice.
Over seventy-five years ago on a pleasant evening I looked up at the Milky Way and with my limited knowledge of astronomy was extremely impressed with the immensity and age of the universe. I was probably more impressed with God who had made it. I had just been to confession and was moved that the creator of the universe was so good to me. I am in awe of many wonders of nature, from the smallest to the largest, and especially humans. I think it may be one reason I have been able to see evolutionary connections as part of God’s process of creation. Jesus has said that no one knows the Father except himself and those to whom he chooses to know his Father.
I see the things others fail to see in evolution as evidence I have been granted some advantage because of my awe of God and his creation and love for all of us. It seems to me that God has prepared me for this via some of the things I earlier viewed as misfortunes and other haphazard choices and/or events in my life. It has not been a total “comedy of errors”, but I cannot attribute great wisdom to the haphazard direction of my life.
A neat and tidy life with thoughtful attention to career progress would not be likely to produce the eclectic bits of information and research needed to reconcile the annelid theory with the actual course of evolution. I think Jesus knows this and has intervened to keep me going to help others see the validity of evolution and in particular, that scientists may see that belief in God is not only compatible with understanding evolution, but also may be a source of divine grace to help that understanding.
The eureka moment of my most important contribution to science will be discussed in my next post. The major role of asteroids, extinctions, and their interaction with deep sea ecology in determining major early events in evolution may be better appreciated by reading pertinent evolution posts in this blog. I thought the eureka moment was to be expected in light of the peculiar collection of events in my academic/scientific life. But I now think it was part of God’s plan for me as evidenced by a number of things.
First, a nudge to complete an evolution book that I had little accomplished toward in my first ten years of retirement. The nudge was a diagnosis of myelodysplasia and the realization I would be lucky if I survived two years, about the time it took me to complete a first draft. Some minor efforts to find a publisher convinced me I should put my work on an internet website. My computer expertise had never been great in the days of punchcards, tape, and eventually disk storage of data (hurrah for thumb drives and if I could get over my fears, cloud storage).
The second nudge, I was struggling with developing a website a few years after surgical removal of a large bladder-stone, (but no prostate ablation due to low platelet counts). Following the worst episode of bleeding since the surgery I had a serious talk with Jesus, I let him know I was ready to die, but if he wanted me to set up an internet presence I would take a bleeding stop as the indication. That was almost five years ago, I was able to set up this blog within a month or so, and have had no bleeding from the urogenital tract since.
I have had serious bleeding from falls and hernia surgery, especially from the last nighttime fall a few months ago that may have been partially due to an episode of pneumonia. So now, ten years after finding I had myelodysplasia, I am happy to see every day but starting to take them for granted. The first day of golf in 2008 I was just soaking up the beauty of the day, spring flowers, fluffy clouds and all that I expected would be my last year. Whenever the day comes, know that I appreciate the days I’ve had, family, friends, colleagues, and many others that have crossed my path. And I hope that some of what I have written will benefit you.
So talk to Jesus, He will hear you and do what is best for you. Thank him. Pray for others, they are his friends too.
Joseph Engemann Kalamazoo, Michigan December 11, 2017