April 25, 2002 |
The coiled molecules of DNA in human cells carry a unique chemical code that can match a trace of blood, semen, skin or hair to the person who left it. DNA (deoxyribonucleic acid) carries its code in four characters denoted by the letters A,T, C, and G. But no microscope is powerful enough to see how this code is arranged on a given DNA molecule, so science must use more indirect methods to read it. Forensics laboratories use several different methods for determining whether two samples indeed carry identical stretches of code.
July 3, 2000 |
They seemed unlikely candidates to make one of the pivotal discoveries of the 20th century. Francis H.C. Crick was a 35-year-old Ph.D. candidate who had abandoned physics, hoping to find his niche in biology. James D. Watson was a gawky-looking 24-year-old who rarely bothered to tie his shoelaces. Both scientists were supposed to be working on other things, but they believed fervently that the most important scientific problem of their time was the mystery of inheritance - how everything from diseases to hair color to the very instructions to make a human being was passed on from generation to generation.
June 3, 2004 |
A man arrested recently in Puerto Rico for domestic offenses resembles the composite of the Fairmount Park rapist, city police said yesterday, adding that the suspect has lived in Philadelphia. As a result, the man, whose name was not released, has agreed to provide DNA that will be compared with evidence collected in the murder and rape of medical student Rebecca Park in Fairmount Park and the rape of another woman off Kelly Drive. The Fairmount Park assailant is also suspected of a third attack on the West River Drive in which the victim managed to fight off her attacker.
October 12, 2006 |
Do you have the feeling you're related to someone famous? Maybe it's an uncanny sense that Mozart was your ancestor. Or that Genghis Khan might be in your family tree. That affinity you feel for ancient Rome can't be an accident, can it? Touring the toppled ruins of columns and friezes in the ancient city stirs something in you. Perhaps one or your ancestors was one of those emperors, or perhaps just a Roman soldier. It's in your blood. Now, with a simple swab of your cheek and a few hundred dollars, you can find out. Commercial genetic genealogy is barely five years old, but already it is proving irresistible to many.
November 4, 2011 |
POLICE yesterday announced the arrest of a man who allegedly raped a 40-year-old woman outside the Linc during an Oct. 5, 2008, Eagles-Redskins game. "It was obviously a real challenge for us because of the number of people in and around that stadium," Special Victims Unit Capt. John Darby said yesterday. "It's almost like finding a needle in a haystack. " Police said they arrested Tiaghgee Daughtry, 22, who lives in Tunkhannock, Pa., near Scranton, on Wednesday, for allegedly raping the woman on a bus during the game.
December 26, 1996 |
No one really knows what happened to Phil Purcell's plane that day in September 1963 over Kontum, Vietnam. A relief pilot saw him turn his ancient B-26 back toward Da Nang. But he never arrived - plunging, instead, into the highlands below and vanishing beneath the oncoming tide of history. For three decades, as his bones and those of his crewmates moldered in Vietnam, as his children grew up and his wife remarried, the story of who he was lay locked in his body's DNA, like a song waiting to be heard.
June 4, 2000 |
Why do visions of war and hacked, stub-limbed civilians from Africa fail to move us as much as the images of civilians under attack in other parts of the world? I contend that we - whites, blacks and blends - are less moved by images from Africa because we've lost the emotional connection with the branch of the African human family tree. Geneticists recently have published results that say we all share the same DNA with slight variations based on traumas and the places we've passed through, via our ancestors.
November 4, 1998 |
For 41 years, the boy in the box has rested in his pauper's grave - unidentified, his murder unsolved. Yesterday, in a final attempt to find his killer, police removed him from his solitary grave in a potter's field in Northeast Philadelphia. They took his body to the medical examiner's office, where technicians will try to extract DNA from his remains. They hope such evidence will help identify him and eventually help nail his killer. "It's hard but it's been done before," said Lt. Ken Coluzzi, head of the special investigations unit at the police Homicide Division.
June 29, 1996 |
Investigators now believe murdered suburban athlete Aimee Willard was sexually assaulted. Preliminary lab tests found semen, but no evidence of the sexual trauma, sources said yesterday. Still, based on interviews with Willard's friends and family, investigators do not believe she had consensual sex, sources said. Willard, 22, of Brookhaven, Delaware County, was a senior at George Mason University in Fairfax, Va., where she played lacrosse. She was beaten to death June 20, and her body was dumped in a vacant lot in North Philadelphia.