What are DNA Ancestry Tests?
An ancestry DNA test is used to determine a person’s roots and origin of DNA, where their ancestor came from, where their family migrated from, and how much of the migrated DNA they have.
How Ancestry Tests Work?
DNA testing is a technique that analyses the structure of a person’s genome by taking DNA samples from their hair, fingernail, skin, or blood. DNA testing can be used to determine parentage (or lack thereof), ancestral history, and even assist police in investigating a crime scene.
DNA, genes, and chromosomes are found in nearly every cell in your body. Each performs a distinct and interrelated function:
DNA: DNA (deoxyribonucleic acid) is a double-stranded molecule that contains all of your genetic information. Adenine (A), thymine (T), cytosine (C), and guanine are the four components of DNA (G). The unique sequence of these substances serves as Individuals body’s “programming code.”
Also Read: DNA Extraction
There are four types of DNA:
- Y-DNA, which only occurs on the Y-chromosome, is passed down from father to son through the generations and is only inherited by males.
- X-DNA, which only occurs on the X-chromosome, is inherited by women from both parents, and by men from the mother.
- Mitochondrial DNA(also known as mitochondria or mtDNA) is passed down through the maternal line and is inherited by sons and daughters, but only passed on by females. It is the least changeable type of DNA, found outside the cell nucleus, not on a chromosome.
- Autosomal DNA can be inherited from hundreds of thousands of your ancestors through the ages. Autosomal DNA can be found in 22 chromosomes and provides 90% of your DNA.
Genes: A gene is a segment of DNA that contains the coded instructions for building specific proteins. While a gene is designed to function in a consistent manner, any flaws in its DNA coding can affect how those instructions are delivered. These flaws are known as genetic mutations.
Chromosomes: Chromosomes are threadlike structures made of protein and a single DNA molecule that transport genomic information from cell to cell. Chromosomes are found in the nucleus of cells in plants and animals (including humans). Humans have 46 chromosomes in total, with 22 pairs of numbered chromosomes (autosomes) and one pair of sex chromosomes (XX or XY). Each pair has two chromosomes, one from each parent, so children inherit half of their chromosomes from their mother and half from their father. When the nucleus dissolves during cell division, chromosomes can be seen under a microscope.
DNA Ancestry Tests
There are several types of DNA ancestry tests available to the public.
Y Chromosome Testing: The Y chromosome is only used to test a specific male line. Fathers pass on their chromosomes to their sons. This DNA ancestry test can be used to determine whether two families with the same surname are related.
Mitochondrial DNA Testing: Within living cells, structures called mitochondria provide energy to the cell. Because these structures have their own mitochondrial DNA, they can be tested. The DNA test is available for both sexes. Because it includes female ancestry DNA, this type of test may provide more accurate results.
Single nucleotide polymorphisms (SNPs) Tests: SNPs are the most common genetic variations between people. SNP testing can be used to evaluate DNA from a wide range of variations across the entire set of genes. When compared to Y chromosome or mitochondrial DNA testing, which only looks at single ancestral lines, SNP testing may be more effective in providing details about your cultural origin.
What is Forensic DNA Testing and How Does it Help in Crime Investigation?
Forensic DNA testing is the application of DNA testing to the investigation of crimes. DNA has also been used extensively to exonerate alleged criminals. When a suspected family member is able to provide a sample, forensic paternity testing can help with missing person or victim identification. It can also be used to prove rape or incestuous relationships when conception occurs.
Since solving its first case in 2018, forensic genealogy has assisted in the identification of suspects in dozens of murder and sexual assault cases. To match individuals to DNA samples, forensic genealogists use genetic information. This frequently entails using open-source databases like GEDMatch. While GEDMatch does not provide genetic testing, it does allow the upload and comparison of DNA data from third-party sources, such as Ancestry.com or 23andMe. GEDMatch has over 1.2 million genetic profiles, which is enough to identify a third cousin of a DNA sample in 90 percent of the US population. Using public records and traditional sleuthing, law enforcement can then use this efficiency to begin building a family tree of a suspect and/or victim.
Also Read: DNA Soled Cold Cases
