VII. GENETICS AND EVOLUTION (Phylogeny)

There are several rather exciting and highly controversial topics in this field today (the nonsense of "scientific" creationism is definitely not one of them). Theories abound, some are incompatible with others, most will surely be combined when the dust settles a bit. You should know about them, and you should be sensitive to the realities of arguments between scientists. Some of these arguments are dependent upon details, some on generalizations, rarely does a proponent of one absolutely reject another. Usually, the one side of such "arguments" seeks simply to modify or to append the "theory" which is the point of view accepted by the second side. This is essential to the cautious, but real, development of the organized body of knowledge to which we refer as "Science". Every once in a while the lunatic fringe of society zeros in on one of these arguments regarding scientific "theory", and (specifically because these folks do not understand the process) they claim that reputable scientists in "the field" disagree with, or condemn, such and such a theory. In their ignorance they judge arguments designed to explore subtleties as arguments about absolute right and wrong, or black vs. white.(This often intrudes in courtroom decisions.)

1. NEW ASPECTS OF "TRADITIONAL" CONCEPTS:

Gradual vs. Punctuated: Just how gradual is "gradual" evolution. When you read, try to keep in mind that to a paleontologist 10 million years is fast, and 50,000 yr. is essentially not a time difference while geneticists think in terms of 70 year human lifespans and 20 year generations. By the way, this is one of those "arguments" which some painfully illiterate people have actually cited as proof that modern scientists do not believe in Darwin's concepts and might support the "creationist" notion that the world was popped into being between 4,000 and 10,000 years ago. The info in these papers is directly cited as scientific evidence that "scientists" no longer believe in evolution. S. J. Gould has been cited as "a reputable scientist who considers Darwin's theories to be in error" (that part is technically "correct", he has offered some changes in the common interpretation of evolutionary events), he has been said, therefore, to support the creationist point of view. That probably makes Dr. Gould a trifle ill!! It is about as incorrect a statement about his theories as could be made. He has never suggested that evolution was an incorrect concept.

There are a variety of new topics in evolutionary circles. The prion (bit of protein) has become important as we work to understand mad cow disease.

NEW TRICKS? (Mendel's concepts still hold -but, nothing is ever simple.)-----------------

- *Marx, J. 1978. Gene structure: More surprising developments. Science 199:517-518.

- *Science News, 1977. Gene parts sandwich surprise segments.

- *Science News, 1977. Animal genes do it differently.

- *Marx, J. 1981. A movable feast in the Eukaryotic genome. Science 211:153-155.

And then – there’s Woese.

There are 3 common ways to examine evolution/taxonomy/phylogeny

A. Whittaker's convenient 5 kingdom system, while still very good as a beginning, cannot serve us when it comes to understanding the Monera and Protists.

B. THE ENDOSYMBIONT THEORY: *(Can you describe it in a short paragraph?? Try.)

*Margulis (nee Sagan), L. 1968. Evolutionary criteria in thallophytes: a radical alternative. Science 161:1020-1022. It is no longer "radical". It is the most accepted model, at present, in the field. You MUST be able to describe the endosymbiont theory in simple terms. (There's a paper from Sci. Amer. to help if you find the Science paper a bit too much for your background. The Science paper is truly a "benchmark" paper. At least try to read it. I have a step by step examination of the endosymbiont theory on the web at

http://envsci.rutgers.edu/~kkeating/101_html/101syllabus_html/lect07_html/

There additional material related to taxonomy, but the Endosymbiont theory takes a bit of examination in detail. It is easy to sort. The file can be ftp’d from list at

http://envsci.rutgers.edu/~kkeating/101_html/ftp_html/

C. The Archaea (Woese) have posed some of the most entertaining scientific paradoxes uncovered in decades. Believe it, or not, the best recent overview of current theory that I have seen is from National Geographic. It is very balanced, very authoritative, very "up-to-date", AND it is VERY readable.

* National Geographic. 1998. The rise of life on earth. 193(3 - March):54-81 (plus "From the editor).

* Scientific American. _____________________________________________________________

_______________________________________________________________________________

2. MOLECULAR BIOLOGY (history):

- *Rich, 1980. Bits of life. The Sciences (October) 10-13, 25. Be grateful to him, this is one of the most readable summaries I have yet encountered. It will bring you through a bit of history in only a couple of pages.

- Kamen, 1958. A universal molecule of living matter. Scientific American. *Just take note of the apparently diverse applications to which the tetrapyrol structure has been applied. What might be its value--there must be some reason why it is so popular with biosynthetic pathways. You have a souvenir copy of one of the most important tetrapyrol-based molecules (B12). Did you notice it?

3. FIDDLING AROUND WITH MOM NATURE:

We have come so far, so fast. Consider the series of steps from the first picture of the alpha-helix (Watson and Crick) to today. It makes an intriguing argument for the J-curve in all human endeavors. Read the next 7 titles, perhaps one will capture your curiosity. I just wanted you to see a cross section of events which matter to you! (At least peruse the titles!)

- Weiss, R. 1991. Novel antibodies beat bacterial toxins. Science News 139:100

- Gibbons, W. 1991. Genetic markers improve colorectal screen. Science News 139:103.

- Weiss, R. 1991. Upping the antisense ante. Science News 139:108-109.

- Fackelmann, K. 1991. Gamma interferon slays microbial invaders. Science News 139:116

- Weiss, R. 1991. Gene defect tied to Alzheimer's cases. Science News 139:117.

- Ezzell, C. 1992. Sheep chimera makes human blood cells. Science News 141:182.

- Anon. 1992. Alzheimer's disease. See how they run. The Economist. 322(7751):94-95.

The rest of this section is NOT optional. (min. 19 p.) We have to discuss the following!

*Marx, J. 1987. Rice plants regenerated from protoplasts. Science 235:31-32. Especially note the date. Carrots came a couple of decades earlier.

*Macklin, R. 1997. Human cloning? Don't just say no. U.S. News & World Report 122(9):64.

*Editors. 1997. Hello Dolly: Cloning and its temptations. The Economist 342(8006):79-81, 17-18, and 59 (a closer parallel than you might think).

*Couzin, J. 1999. What’s killing clones? U.S. News & World Report 5/24/99 pp. 65.

*Herbert, W.; Sheler, J.; and T. Watson. 1997. The world after cloning: A reader's guide to what Dolly hath wrought. U.S. News & World Report 122(9):59-63.

**Chedd, G. 1977. Wonderful sickly microbe. Nature/Science Annual Time-Life 93-97. The older this paper gets, the BETTER it becomes! Can caution be justified in all gene transfer applications because of the extraordinary talents of this particular creature? (Careful, generalizations are the bases for most socially expressed prejudice.) There was a time in the not too distant past when all genetic experiments were put on hold. In fact the town of Cambridge, Mass., voted to keep such research OUT of town. [[Question - What actually made that microbe "Wonderful" ?]]

*Sinha, V, and B. Srivastava. 1978. Plasmid-induced loss of virulence in Vibrio cholerae. Nature 276:708-709. You don't have to read it all, but can you decide - is Cholera a bacterial disease, or a viral disease, or-?

Lee, A. and R. Langer. 1983. Shark cartilage contains inhibitors of tumor angiogenesis. Science 221:1185-1187. Just how many "useless" or offensive species of creature can we afford to exterminate? This living fossil is an unpleasant swimming companion----but----

4. A NOTORIOUS SOVIET FAKIR--SURELY CAPITALISM'S FRIEND.

*Time-Life Scientific Annual. 1976. Death of Stalinist science. Everyone should know of Lysenko. p. 171 and the damage he did to Soviet science. - *WHY is it critical to environmental science?

This is a frustrating set of readings for me. In several cases unlisted inclusions are at least as worthwhile as listed ones. Yet, my suspicions are that you will probably only read the "required" ones. You will be missing some neat stories. Seriously consider rummaging thru the full set of readings. Just for the scientific curiosity you once claimed to possess.