CARL WOESE: BIOGRAPHY, TAXONOMY, OTHER CONTRIBUTIONS, WORKS - ARTE - 2025

Carl Woese (1928-2012) was a renowned American microbiologist whose work revolutionized the understanding of the microbial world, as well as the way we perceive the relationships of all life on Earth.

More than any other researcher, Carl Woese focused the scientific world's attention on an intangible but dominant microbial world. Their work allowed us to know and analyze a kingdom that extends far beyond pathogenic bacteria.

Carl Richard Woese was an American microbiologist whose work revolutionized the understanding of the microbial world. Source: Don Hamerman

Through his works, Woese developed an understanding of the development of life; This was achieved through the sequence of genes of living beings, thus showing that evolutionary history can be traced back to a common ancestor.

Furthermore, during this investigation, Woese discovered the third domain of life known as the archaea.

Biography

Carl Richard Woese was born in 1928 in Syracuse, New York. He studied mathematics and physics at Amherst College in Massachusetts and earned a PhD. in biophysics at Yale University in 1953.

Woese received his training from leading researchers and Nobel laureates, such as his graduate instructor, the biophysicist Ernest Pollard, who was himself a student of the Nobel Prize winner in physics James Chadwick.

Woese's interest in the origin of the genetic code and ribosomes developed while working as a biophysicist at the General Electric Research Laboratory. Later, in 1964, the American molecular biologist Sol Spiegelman invited him to join the faculty of the University of Illinois, where he remained until his death (2012).

Woese's Human side

According to his close colleagues, Woese was deeply dedicated to his work and was very responsible with his research. However, many say that the microbiologist had fun while doing his jobs. Furthermore, his classmates described him as a brilliant, resourceful, honest, generous and humble person.

Awards and distinctions

Throughout his years of research he received many awards and distinctions, such as the MacArthur Fellowship. She was also a member of the United States National Academy of Sciences and the Royal Society.

In 1992, Woese received the Leeuwenhoek Medal from the Royal Netherlands Academy of Arts and Sciences - considered the highest award in microbiology - and in 2002 he was awarded the United States National Medal of Science.

Similarly, in 2003 he was awarded the Crafoord Prize of the Royal Swedish Academy of Sciences in Biosciences, a parallel prize to the Nobel Prize.

Determining scientific advances for Woese's vision

In the 1970s, biology classified living beings into five large kingdoms: plants, animals, fungi, prokaryotes (or bacteria), simple cells without internal structure, and eukaryotes that do have a nucleus and other components in their cells..

However, advances in molecular biology allowed Woese to take a different look at the fundamentals of life on Earth. In this way, he showed that life in each of the five kingdoms has the same base, as well as the same biochemistry and the same genetic code.

The genetic code

After the discovery of nucleic acids, Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA), it was determined that the genetic code is stored in these two macromolecules. An essential characteristic of DNA and RNA is that they are made up of repeats of smaller molecules known as nucleotides.

Thanks to this, it was possible to establish that the great diversity of life is due to the differences in the components of the nucleotides of these two molecules.

In this regard, Woese's contributions on how to understand and determine the structure of RNA were essential. After conducting these investigations, Woese became especially interested in the study of the evolution of the genetic code.

Molecular taxonomy

Carl Woese studied a particular set of genetic information found in so-called 16s mitochondrial RNA. The genetic sequence of this RNA has the peculiarity that it appears in the genomes of all living beings and is highly conserved, which means that it has evolved slowly and can be used to track evolutionary changes for a long time.

To study RNA, Woese used nucleic acid sequencing technology, which was still very primitive during the 1970s. He compared the ribosomal RNA (rRNA) sequences of various organisms, primarily bacteria and other microorganisms.

Later, in 1977, together with George Fox, he published the first scientifically-based phylogenetic tree of life. This is a map that reveals the large-scale organization of life and the course of evolution.

The three domains

The evolution model used before Woese's work indicated that living things were classified into two large groups: prokaryotes and eukaryotes. Furthermore, he pointed out that prokaryotes gave rise to more modern eukaryotes.

However, Woese sequenced and compared the rRNA genes of different living things and found that the greater the variation in the gene sequence of two organisms, the greater their evolutionary divergence.

These findings allowed him to propose the three evolutionary lines, called domains: Bacteria and Archaea (representing prokaryotic cells, that is, without a nucleus), and Eukarya (eukaryotic cells, with a nucleus).

Archaeas represent prokaryotic cells, that is, without a nucleus. Source: Kaden 11a

In this way, Woese established that the concept of prokaryotes had no phylogenetic justification and eukaryotes did not originate from bacteria, but are a sister group to archaea.

The phylogenetic tree of life

The three domains were represented in a phylogenetic tree, where evolutionary differences are shown. In this tree, the distance between two species - drawn along the lines that connect them - is proportional to the difference in their rRNA.

Likewise, those widely separated in the tree are more distant relatives and, by combining a large amount of data, it is possible to estimate the relationships between species and determine when one line diverged from another.

Other contributions

Woese's work and findings had a profound impact on the way of understanding the development of the microbial ecology of the earth and the human body; even outside the terrestrial dominions.

Contributions to the ecology of the Earth

Microbial ecosystems are the foundation of Earth's biosphere, and before Woese's sequence-based phylogenetic framework was developed, there was no meaningful way to assess the relationships of the microbes that make up the natural world.

Woese's discovery demonstrated that all life on Earth descends from an ancestral state that existed 3.8 billion years ago, with the key elements of the modern cell already established.

In this way, the discipline of microbial ecology was propelled from a dying state to one of the most vibrant fields of biology with important ramifications for medicine, as demonstrated by the Human Microbiome Project.

Human Microbiome Project

The Human Microbiome Project was proposed in 2008 by the United States National Institute of Health (NIH), with Woese's findings being the fundamental basis of this project.

The main objective of this great initiative is to identify and characterize the microbial communities present in the human body and to look for the correlations between the dynamics of microbial populations, human health and diseases.

Exobiology

Exobiology attempts to reconstruct the history of the processes and events involved in the transformations of biogenic elements, from their origins in nucleosynthesis to their participation in Darwinian evolution in the solar system.

Consequently, exobiology addresses the fundamental aspects of biology through a study of life outside of Earth. A general theory then arises for the evolution of living systems from inanimate matter.

Woese's concepts were incorporated by NASA into its exobiology program and into the philosophies of its programs for the missions that were launched to Mars to search for signs of life in 1975.

Main works

His most important works are listed below:

- Evolution of macromolecular complexity (1971), where a unified model for the evolution of macromolecular complexity is presented.

- Bacterial evolution (1987). This work is a historical description of how the relationship between microbiology and evolution begins to change the concepts about the origin of species on Earth.

- The universal ancestor (1998). It describes the universal ancestor as a diverse community of cells that survives and evolves as a biological unit.

- Interpreting the universal phylogenetic tree (2000). This work refers to how the universal phylogenetic tree not only encompasses all existing life, but its root represents the evolutionary process before the emergence of current cell types.

- On the evolution of cells (2002). In this work, Woese presents a theory for the evolution of cell organization.

- A new biology for a new century (2004). It is a statement about the need for a change in the approaches to biology in light of the new findings of the living world.

- Collective evolution and the genetic code (2006). Presents a dynamic theory for the evolution of the genetic code.

References

1. Woese C, Fox GE. (1977). Phylogenetic structure of the prokaryotic domain: the primary kingdoms. Retrieved on November 11 from: ncbi.nlm.nih.gov
2. Woese C. (2004). A new biology for a new century. Microbiology and molecular biology reviews. Retrieved on November 12 from: ncbi.nlm.nih.gov
3. Rummel J. (2014). Carl Woese, Dick Young, and the roots of astrobiology. Retrieved on November 13 from: ncbi.nlm.nih.gov
4. Goldenfeld, N., Pace, N. (2013). Carl R. Woese (1928-2012). Retrieved on November 13 from: science.sciencemag.org
5. Human Microbiome Project, HMP. Retrieved on November 13 from: hmpdacc.org.
6. Dick S, Strick J. (2004). The living universe: NASA and the development of astrobiology. Retrieved on November 12 from: Google Scholar
7. Klein H. (1974). Automated life-detection experiments for the Viking mission to Mars. Retrieved on November 12 from: nlm.nih.gov