With one look, you can usually tell whether someone is old or young. Wrinkled skin or smooth, thinning hair or thick locks, bifocals or Ray-Bans, these are just a few of the overt clues. Far less obvious are the age-related signs that show up on the molecular level. Ask a geneticist where to look and he may point you to a person's mitochondria. These residents of an animal cell provide the cell with energy, and each mitochondrion has its own DNA strand, which is distinct from the DNA in the chromosomes that dwell in the cell's nucleus. With age, this mitochondrial DNA becomes riddled with mutations, both subtle and severe. If a human body were to be found lying in the woods, the first thing after a thorough search done by professional forensic and investigative team would be to send it to forensic pathologist for an examination. The post-mortem examination of a body, or autopsy, is an examination of a corpse in order to determine cause of death. The autopsy starts with a thorough exterior examination of the body. X-rays are taken and the body is photographed extensively, while the presiding forensic pathologist makes notes about any distinguishing features on the body, and any visible injuries. Sometimes the cause of death is readily apparent during this examination, as might be the case with someone who was decapitated, but the internal examination of the body is also important. The major organs of the body such as the heart, liver, lungs, and stomach are removed for examination, and small samples are taken for lab inspection. Indicators of disease are noted, and usually the stomach is opened so that its contents can be examined. Samples of body fluids are also taken so that they can be tested for drugs, toxins, and any other unusual substances. While the process of an autopsy may seem gruesome to some, autopsies can provide valuable medical clues. Especially in terminally ill patients, an autopsy can provide information for doctors about the exact cause of death which may help them treat other patients with similar conditions in the future. It can also help determine the general information about the body, such as sex, age, height, etc. For now, focusing on age determination seems like a critical question among scientists as more and more information is being discovered regarding DNA and its effect on the aging of human body. Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster because the age at death, birth date, and year of death as well as gender can guide investigators to the correct identity among a large number of possible matches.
Age is reflected in many ways when examining a human body, whether dead or alive. The human body is made up of fat, muscles and organs, bones, water, and other substances. As we age, the amount and distribution of these materials will change. Fat tissue may increase toward the center of the body, including around the abdominal organs. The amount of body fat may increase by as much as 30%. As fat increases, lean body mass decreases. Your muscles, liver, kidney, and other organs may lose some of their cells. This process of muscle loss is called atrophy. Bones may lose some of their minerals and become less dense, a condition called osteoporosis. Tissue loss reduces the amount of water in your body. You may become shorter. The tendency to become shorter occurs among all races and both sexes. Height loss is related to aging changes in the bones, muscles, and joints. People typically lose about 1 cm (0.4 inches) every 10 years after age 40. Height loss is even greater after 70 years old. In total, you may lose 1 to 3 inches in height as you age.
Our bones can tell more about a person’s age if looking at it upon an autopsy table. Bone mass or density is lost as people age, especially in women after menopause. The bones lose calcium and other minerals. The spine is made up of bones called vertebrae. Between each bone is a gel-like