Internet Research on Carl Woese . Carl Woese (1928-2012) was an American scienti

Question

Internet Research on Carl Woese. Carl Woese (1928-2012) was an American scientist who was mainly interested in microorganisms - organisms so small that they can only be seen with a microscope. In particular, Woese sought to organize the known species of microorganisms, according to their relatedness, into a classification scheme. When he started, he felt that the classification schemes in use at the time were based on highly questionable assumptions, and quite possibly were complete rubbish. Therefore, he worked out a new method for classifying organisms. Research his activities on the internet, and then address issues (a), (b) and (c), that are given below, and cite your source(s).

(a) Briefly describe Woese’s new method for classifying microorganisms. Please note that you don’t need to get into all of the details, such as the virtues of the particular "subunit" he focused on. Instead, I’m looking for you to identify the molecule that Woese analyzed and the basic logic of his approach.

(b) Name one of Woese’s most important findings.

(c) Describe one way that this relates to this week's lesson.

Don't forget to cite your source or sources.

Explanation / Answer

Carl Woese developed the modern gene sequence–based understanding of biological organization, showing that the evolutionary history of lineages can be pursued to a common ancestral state. He discovered the third domain of life, which came to be known as the archaea (Goldenfeld and Pace 2013). Woese is famous for defining the Archaea by phylogenetic taxonomy of 16S ribosomal RNA, a technique pioneered by Woese which revolutionized the discipline of microbiology (Woese and Fox 1977, Woese et al.,1978, Woese, et al.,1990, Morell, 1997).

His 1967 book The Genetic Code broached the notion of a prebiotic "RNA world," still a focus of thought on the origin of life (Woese, 1967). He is known for his fundamental contributions on determining and understanding large RNA structures. Nevertheless Woese's most revolutionary achievement was his use of primitive nucleic acid sequencing technology to compare ribosomal RNA (rRNA) sequences from diverse organisms, mostly microbes, and to report in 1977, with George Fox, the first scientifically based phylogenetic tree of life in essence a map that revealed the large-scale organization of life and the early course of evolution (Woese and Fox 1977). Carl put our picture of living organisms on a solid empirical basis using the tools of molecular biology (Shapiro, 2013).

The model of deep evolution then still taught in most of our textbooks today was that all life is one of two kinds, prokaryote or eukaryote, and that prokaryotes gave rise to more modern eukaryotes. Instead, Woese's data showed three kinds of organisms and thus, three domains: eukaryotes, the classic bacteria, and the newly discovered archaea. The concept of prokaryotes had no phylogenetic justification; the eukaryotic nuclear lineage (in contrast to the bacterially derived mitochondria and chloroplasts) did not originate more recently than bacteria or archaea, but was primordial and a sister group to the archaea. These radical claims inflamed many evolutionists, but his three-domain classification is now widely accepted and is supported by much correlation (Goldenfeld and Pace 2013).

References:

Goldenfeld Nigel and Pace Norman R. 2013, Carl R. Woese (1928–2012), Science 339: 6120, 66.

Morell, V. (1997). "Microbiology's scarred revolutionary". Science. 276 (5313): 699–702. doi:10.1126/science.276.5313.699. ISSN 0036-8075. PMID 9157549.

Shapiro James A., 2013, In Memorium Carl Woese (1928-2012), the Most Important Evolutionary Biologist of the 20th Century, THE BLOG dated 01/28/2013, www.huffingtonpost.com

Woese, C. R. G. E. Fox (1977). "Phylogenetic structure of the prokaryotic domain: The primary kingdoms". Proceedings of the National Academy of Sciences. 74 (11): 5088–5090.

Woese, C.R.; Magrum, L.J.; Fox, G.E. (1978). "Archaebacteria". J Mol Evol. 11 (3): 245–51.

Woese, Carl R.; Kandler, O; Wheelis, M (1990). "Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya" (PDF). Proc Natl Acad Sci USA. 87 (12): 4576–9.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.