All posts in Thermal features

Thinking my blog followers might like to learn about the interesting connection between a microorganism found in Yellowstone Park and a notorious criminal trial twenty years ago—recent enough that some of you will have followed that trial—I’ll repeat here something I wrote last spring for another website.
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One thing leads to another. So let’s play Connect Initials and Years. Specifically, let’s examine how a microbe found in Yellowstone National Park (YNP) related to evidence from a sample of deoxyribonucleic acid (DNA) in the most famous criminal trial of the late twentieth century.

1966: Indiana University professor Thomas D. Brock (TDB) and undergraduate assistant Hudson Freeze collect a tiny organism from 73ºC Mushroom Pool in YNP. The bacterium, named Thermus aquaticus (TAQ), is subsequently found to thrive in the laboratory even in boiling water and is deposited with the American Type Culture Collection (ATCC).
[Photo of Brock at Mushroom Pool by Janet Chapple, 1996]

1975 and 1977: Doctor Frederick Sanger of Cambridge University and colleagues publish two papers that made DNA sequencing in the lab much less laborious than it had been previously—and for which he won his second Nobel Prize (in 1980).

1983–84: Researcher Kary Mullis and team at Cetus Corporation, Emeryville, CA, buy a sample of TAQ for thirty-five dollars from the ATCC. From this they purify an enzyme known as Taq polymerase. It proves to be so stable, even when repeatedly heated and cooled, that it can be used to conduct repeated reactions and produce a large amount of DNA from a minuscule example, a technique called a Polymerase Chain Reaction (PCR).

For demonstrating this improved PCR technique, Mullis shared the Nobel Prize in Chemistry. Cetus and later their successor company Hoffmann–LaRoche made hundreds of millions of dollars in patent rights and licenses.
[Computer-rendered view of a random DNA double-helix by Geoff Hutchison
From Creative Commons.Freely shared with attribution; no derivatives.
from Creative Commons]

1986–96: DNA sequencing becomes more and more important in several fields of endeavor, among them archaeological research, proof of paternity, prenatal health, the origins of species—and forensics. DNA evidence was used for the first time in a U.S. criminal court in 1987. However, note here that not until 1996 did the National Academy of Sciences (NAS) announce the reliability of DNA evidence.

1994: A National Institutes of Health (NIH) website points out that “The DNA Identification Act of 1994 authorized the Federal Bureau of Investigation (FBI) to expand a pilot project into a national DNA database, the Combined DNA Index System (CODIS), as a tool for solving violent crimes.” Thus, this national database had just been authorized in 1994 and was not fully functioning until 1998.

1994–95: Football star O. J. Simpson (OJS) [from Wikipedia Commons, 1990]
is the defendant in a widely televised eleven-month-long trial for the murder of his ex-wife Nicole Brown Simpson and her companion Ronald Lyle Goldman. The prosecution presented DNA evidence to the jury. However, (quoting the Crime Museum website): “A major hurdle that the prosecution team failed to overcome was the lack of knowledge and understanding regarding forensic science, specifically DNA.” And, “This inability to understand key evidence made the evidence essentially useless; even some seasoned lawyers found the scientific testimonies to be incomprehensible. It is reported that the DNA evidence showed that the chance that some of the blood found near the bodies came from anyone but Simpson was one in 170 million. The chance that blood found on Simpson’s sock could be from someone other than Nicole Brown was one in 21 billion.”
The trial verdict was Not Guilty.
At the time of this high-profile trial even such responsible entities as the NAS and the FBI were unsure or did not yet fully appreciate the implications of DNA evidence. Thus, a murderer was not convicted.

Early 2000s: Taq polymerase becomes only one among a number of DNA polymerases that are used in sequencing reactions.

2014: Twenty years after the OJS trial, would a jury decide differently?