Forensics Talk

Eye ON DNA: What Does DNA Mean To You?

Eye On DNA

by Dr. Hsien-Hsien Lei                                                                              
Posted June 18, 2008 in Meaning of DNA

     This post comes from the excellent DNA weblog site Eye On DNA, by genetic genealogist Dr. Hsien-Hsien Lei:

       When I first received this question, I quickly realized that I could probably spend hours answering it. DNA has had such a profound impact on my life that I barely know where to begin.

I guess I should start with my own DNA. As a genetic genealogist, I have sequenced tiny portions of my DNA and the DNA of relatives to learn about the ancestral sources of those sequences. The results have allowed me to understand more about my most distant paternal ancestor who came to America and fought in the Revolutionary War, as well as my most distant maternal ancestor who lived in Central America and had Native American roots (which I discovered from the DNA testing). Although these pieces of DNA passed through these individuals with perhaps only a few small changes before reaching me, seeing these sequences gives me the first tenable insight into these ancestors aside from their name and the date of their birth and death. These tiny pieces of DNA have created a link between me and ancestors who died nearly 200 years ago.

Perhaps even more importantly, genetic genealogy has given me the first piece of information about the ancestry of a paternal great-grandmother who was adopted upon birth. Although this small piece of circular DNA from my paternal great-grandmother is not part of my own genetics, it was a part of her; and every decision she made ultimately led to me. Additionally, it is likely that I inherited some other part of my great-grandmother’s DNA. Thus, genetic genealogy has given me clues to some of the secrets contained within my genome... Read More

New Automated System IDs Victims Of Mass Disasters In Minutes

Science Daily
Nov. 28, 2007

     A new, high-tech identification system developed in Japan will improve accuracy and significantly reduce the time it takes to identify victims of mass disasters, according to a study presented November 27 at the annual meeting of the Radiological Society of North America.

    "Families waiting to hear news regarding loved ones experience trauma while waiting for the identification process to resolve," said Eiko Kosuge, D.D.S., dentist, radiologist and lecturer at the Department of Oral and Maxillofacial Radiology at Kanagawa Dental College in Japan. "With this new system, we can drastically cut the time and improve the accuracy of this process to help alleviate some of the emotional stress that occurs in the case of a mass disaster."

Currently, all cases of dental identification in the wake of a mass disaster have to be handled one by one by forensic experts. After a mass disaster such as an earthquake, tsunami, plane crash or act of terrorism, forensic experts must compare each victim's records with scores of dental records to try to make a proper identification. This can be very time consuming, taking weeks or months, and mistakes do occur... More

Sloppy Police Lab Work Leads to Retesting

New York Times
December 4, 2007
By THOMAS J. LUECK

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         The New York Police Department has begun to test thousands of drug evidence samples, as a review by the state’s inspector general has found that sloppy work by analysts in the department’s crime laboratory could have skewed drug evidence used by prosecutors.

But since the mistakes in the laboratory, the nation’s busiest, were found to have been made in 2002, some of the evidence has been destroyed, making any new tests very difficult, according to the review, which was released yesterday. Legal experts said this could open the door to appeals by those who want to have their convictions overturned or their sentences shortened.

The slipshod drug testing — which may have involved “dry-labbing,” or failing to test all the bags when many were seized — has been acknowledged by the Police Department...“The integrity of evidence is a cornerstone of law enforcement,” Ms. Hamann said yesterday. “These lapses were a threat not only to the prosecution of drug crimes, but to the public’s trust in our criminal justice system...." More

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After Falsified Test Results, Kelly Orders Forensic Shakeup

New York Times
April 20, 2007

By THOMAS J. LUECK

         With the disclosure that two civilian employees reported false results in testing drug bags in 2002 at the police crime laboratory, Police Commissioner Raymond W. Kelly has ordered a shakeup of the Forensic Investigations Division and the creation of an oversight panel, the authorities said yesterday.

The changes come as a rebuke to the forensic unit’s former commander, Deputy Chief Denis McCarthy, who was recently transferred to a patrol division.

Chief McCarthy, a 27-year veteran of the department, was in charge in 2002 when the two employees were found to have engaged in “dry-labbing,” or cutting corners in the process of testing for drugs during an internal integrity test conducted by the department. In addition, the forensics unit failed to report the transgression to state officials and to a national laboratory accreditation board, as it is required to do.

Chief McCarthy’s transfer and the 2002 drug testing falsification were reported yesterday by The New York Post. Mr. Kelly said that Inspector Kevin J. Walsh, formerly of the Counter-Terrorism Bureau, had replaced Chief McCarthy as commander of the forensics division.

A spokesman for the Police Department, Paul J. Browne, said the falsified test results in 2002 had no bearing on actual court cases, since they were revealed in a routine procedure of “blind proficiency tests” designed as internal checks on the integrity and competence of civilian criminalists, 100 of whom are now employed by the crime laboratory... More

New Route For Heredity Bypasses DNA

Medical News Today
Main Category: Biology / Biochemistry
Also Included In: Genetics
Article Date: 07 Jan 2008 - 0:00 PST

  A group of scientists in Princeton's Department of Ecology and Evolutionary Biology has uncovered a new biological mechanism that could provide a clearer window into a cell's inner workings.

What's more, this mechanism could represent an "epigenetic" pathway -- a route that bypasses an organism's normal DNA genetic program -- for so-called Lamarckian evolution, enabling an organism to pass on to its offspring characteristics acquired during its lifetime to improve their chances for survival. Lamarckian evolution is the notion, for example, that the giraffe's long neck evolved by its continually stretching higher and higher in order to munch on the more plentiful top tree leaves and gain a better shot at surviving.

The research also could have implications as a new method for controlling cellular processes, such as the splicing order of DNA segments, and increasing the understanding of natural cellular regulatory processes, such as which segments of DNA are retained versus lost during development. The team's findings will be published Jan. 10 in the journal Nature...More

Study: Our DNA Less Alike Than Thought

             Research Could Help Understand The Genetic Underpinnings Of Disease

NEW YORK, Sept. 4, 2007

     (AP) People are less alike than scientists had thought when it comes to the billions of building blocks that make up each individual's DNA, according to a new analysis.

"Instead of 99.9 percent identical, maybe we're only 99 percent (alike)," said J. Craig Venter, an author of the study - and the person whose DNA was analyzed for it.

Several previous studies have argued for lowering the 99.9 percent estimate. Venter says this new analysis "proves the point."

The new work, in the latest issue of PLoS Biology, marks the first time a scientific journal has presented the entire DNA makeup, or human genome, of an individual.

   However, James D. Watson - co-discoverer of DNA's molecular structure - received his own personal DNA map from scientists a few months ago. And the genomes for both him and Venter are already posted on scientific Web sites... Read More