More Biology

I have been posting some long comments at at Chicagoboyz, and decided to do them as post here. The topic is the future of technology.

I am pessimistic on molecular medicine for several reasons. I have gotten into two nasty debates on evolution at conservative web sites. One was at Ricochet and was nasty enough that I quit going there. There were something like 250 comments, of which about four were friendly. At Althouse, it was a bit better but still very negative, about 4 to 1. I let my membership at Ricochet expire and so can’t find the thread.

Found it with Google.

A sample of comments is here.

No disrespect Mike but I think you are suffering from the same problem that a lot of people suffer from. The inability to factor faith into the intellectual equation. It is possible to understand and embrace the science of evolution and apply the knowledge gleaned from it even if you aren’t 100% sure we have the story right.

I 100% believe the story of creation in the Bible, but I have no problem understand the evolution of the sickle cell trait. In the same way I have no problem believing Jesus brought Lazarus back from the dead or healed the server of a Roman centurion from miles away even though these things seen completely at odds with medical science.

That doesn’t even take into account the anti-GMO lefties who seem to be more accepting of human modification than with plants.

In both cases, I got into it by commenting that I would not write a letter of recommendation for a student applying to medical school who did not believe in evolution. I tried to make the point that I am not the king of medical school admissions but it was no help.

There are plenty of good Christian doctors and biologists who are well-versed in cell biology and in how mutations happen and in natural selection processes that affect microbes and higher organisms. Biology and Chemistry and their processes can be learned and understood. In fact, people who don’t believe in Evolution turn out to be particularly attentive students on these topics, because they are keen to know what they need to know as well as identify when the teacher has gone beyond the topic and wandered into theological weeds.

You slander many very good doctors with your dismissive remarks.

Obviously, there is no way to discuss this with these people and I quit Ricochet. The comments continued long after I left and were no more accepting of evolution.

I spent a year studying molecular biology because it was obvious that, if I was going to talk to medical students, I needed to know something about genetics. I tried to read Lewin’s Gene VII, but quickly realized that I did not know enough molecular biology (which did not exist when I was a medical student).

I spent the next year reading Alberts’ “The Molecular Biology of the Cell”, all 1500 pages.

I then went back to Lewin (which cost $142.) and discovered it had come out in several new editions in the year since I bought my copy. Not only were the new editions more up to date but the old edition was wrong on many points because, since the book was published, Craig Venter had discovered the Human Genome and the older ideas were wrong about it.

I bought the New edition and struggled to understand it. I have finally bought the 2012 edition, which is no picnic to read.

From a review: The second paragraph of the preface of this text says “This book is aimed at advanced students in molecular genetics and molecular biology.” They are not lying. I am sure that this is a great reference if you are doing master’s or Ph.D. level work, but if this is the text that is assigned for an undergraduate course, as it was for me, then go to your department chair and protest. You will spend $200 plus dollars and unless you are a very sophisticated student, you are going to have a hard time getting anything from this text.

I am still struggling but the point of this all is that molecular medicine requires a thorough understanding genetics, which is incomprehensible without evolution.

One small example. Rickettsiae, which are disease causing organisms sort of like bacteria are also very closely related to mitochondria which are the components of human (and animal) cells that allows us to use oxygen.

When the Earth was primitive, there was no oxygen in the atmosphere. Early organisms did fine with non-oxidative metabolism. When the Earth cooled and plants and Cyanobacteria appeared, the atmosphere began to contain more oxygen which is toxic to anaerobic organisms. There was, at that time (The theory presumes), another family of organisms, called now “Rickettsiae,” which can use oxygen. They were ingested by the anaerobic organisms and eventually became parasites, or symbiotes if you will, and they made the oxygen that the organisms required for energy. We came along later.

This bacterium and its relatives represent one of biology’s great ironies. On the one hand, the historical ancestors of R. prowazekii precipitated some of the greatest plagues to afflict the human race (see box overleaf). On the other hand, an evolutionary antecedent of R. prowazekii participated in one of the seminal events in the evolution of eukaryotic (nucleus-containing) cells — the formation of mitochondria, cellular organelles that contain their own DNA and, during oxidative breakdown of glucose, produce the ATP that powers these cells. With the complete genome sequence of R. prowazekii, we can now examine this important genetic blueprint for clues both as to what makes R. prowazekii such a great killer, and what allowed one of its ancestors to contribute so fundamentally to the emergence of eukaryotic cells in the first place.

Eukaryotic means the cells with nuclei like ours. Bacteria are prokaryotic and Archea, which are the oldest living things, are also prokaryotic. Mitochondria have their own DNA suggesting they were once free living and some Rickettsiae are nonpathogenic, they don’t cause disease.

The oxygen atmosphere that we depend on was generated by numerous cyanobacteria during the Archaean and Proterozoic Eras. Before that time, the atmosphere had a very different chemistry, unsuitable for life as we know it today.

The other great contribution of the cyanobacteria is the origin of plants. The chloroplast with which plants make food for themselves is actually a cyanobacterium living within the plant’s cells. Sometime in the late Proterozoic, or in the early Cambrian, cyanobacteria began to take up residence within certain eukaryote cells, making food for the eukaryote host in return for a home. This event is known as endosymbiosis, and is also the origin of the eukaryotic mitochondrion.

Archea may well be found on Mars or even in comets.

Archaea were initially viewed as extremophiles living in harsh environments, such as hot springs and salt lakes, but they have since been found in a broad range of habitats, including soils, oceans, marshlands and the human colon and navel. Archaea are particularly numerous in the oceans, and the archaea in plankton may be one of the most abundant groups of organisms on the planet.


They were discovered by Carl Woese who is revered by microbiologists and who should have been awarded a Nobel Prize.

With regard to Woese’s work on horizontal gene transfer as a primary evolutionary process, Professor Norman Pace of the University of Colorado at Boulder said, “I think Woese has done more for biology writ large than any biologist in history, including Darwin… There’s a lot more to learn, and he’s been interpreting the emerging story brilliantly.”

Nobody but biologists know who he was. He died in 2012 and his name should be well known but it is not.

Anyway, evolution is at the heart of molecular medicine and I think medical students should know it.

“Cyano-bacteria harnessed sunlight, water and carbon-dioxide and metabolized them for energy, keeping only the carbon from the CO2 and releasing the oxygen as a waste product”

This is an incredible story and needs to be more widely known and understood. The relationship between Rickettsiae and mitochondria was first proposed by a biologist when he was lying on the beach on a Greek Island (as I recall) but I can no longer find the article that describes how he came to this concept.

When I was a medical student in 1962, we knew that mitochondria were the source of oxygen metabolism and that the “Krebs Cycle” took place in mitochondria. That was actually very new information. The 1947 Nobel Prize was awarded to the Cori husband and wife for the discovery of The Cori Cycle which was thought to be the origin of ATP and metabolism. It turns out that the Cori Cycle is what happens in anaerobic conditions, like muscle metabolism during exercise, and is not the basic mechanism they thought it was. The Cori Cycle is not powerful enough to supply enough ATP for life in an oxygen atmosphere.

The Krebs Cycle was finally realized as the real ATP system not long before I began medical school.

The citric acid cycle itself was finally identified in 1937 by Hans Adolf Krebs while at the University of Sheffield, for which he received the Nobel Prize for Physiology or Medicine in 1953.

I began medical school 8 years later. All of the structures of the cell, like the Golgi Apparatus were known and we had to memorize all of them but we had no idea what they did.

Now we know: Part of the cellular endomembrane system, the Golgi apparatus packages proteins inside the cell before they are sent to their destination; it is particularly important in the processing of proteins for secretion.

This is why I had to learn all this in 2000.

Part of the mitochondria story is here in Nature.

R. prowazekii is an obligate intracellular parasite — that is, it can only live within other cells. Its gene content, like that of other parasitic eubacteria, has been reduced and tailored to suit its dependent lifestyle. Andersson et al.1 have found that the R. prowazekii genome encodes 834 complete open reading frames, DNA sequences that specify protein sequences. This number is far less than the 4,288 protein-coding genes found in the fourfold larger genome of Escherichia coli, its free-living cousin3. However, R. prowazekii contains ten times as many genes as the most bacteria-like mitochondrial genome described to date, the 69,034-bp mitochondrial (mt)DNA of the freshwater protozoon Reclinomonas americana 4. Surprisingly, the R. prowazekii genome also contains the highest fraction of non-coding DNA (24%) found in any microbial genome so far, much of which may represent inactive genes that have been degraded by mutation, but have not yet been eliminated from the genome.

This is a fascinating detective story. We may find something like these organisms under the soil of Mars where the environment may be more hospitable. I just wish the public were more receptive to these issues, especially that which shares political philosophy with me on other issues. I am slowly losing my patience with the fundamentalist Christian crowd that seems almost as aggressive as the atheist crowd. I am neither.


3 Responses to “More Biology”

  1. doombuggy says:

    Excellent post.

    Evolution has been a political tool of the Left, tossed out by mockers like Bill Maher and John Stewart to diminish conservatives. Never mind that leftists have no belief in evolution when applied to humans.

    The political Right should have done better in managing this issue.

  2. dhmosquito says:

    Thanks. Interesting in that a distinct, perhaps significant, percentage of individuals who identify as Christians apparently believe that one cannot be a “Born-Again Christian” (a term I consider redundant) unless one believes in the quite literal interpretation of the Bible, including Genesis (to include the idea that Earth was created in six 24-hour periods as we know them today), and that belief in evolution is therefore wrong/sinful, that all abortion is sinful (to include the idea that fetal preservation is more important than the life of the mother), premarital sex is sinful, that an evangelistic philosophy is mandated, church attendance is also mandatory, and on and on. And I say this as someone who considers himself a Conservative. And who is a “baptized” Christian. But not a “fundamentalist Christian”. Thanks for the tip on Ricochet; I won’t bother subscribing. I respect your background and enjoy your comments on the other blogs I regularly read. cheers, chuck

  3. TMLutas says:

    It should be a comforting thing for leftists to behold the tolerance on the right for so many fools. We don’t kill them. We don’t imprison them. We don’t do all the things that the left accuses the right of wanting to do. It’s a live exercise in testing the proposition whether the right is a fundamentally benign force in american politics. The right passes this test with flying colors every day and the left mocks it for passing.