DNA question

[terralee]

I know Ive come to the right place to ask this question because there are so many intelligent posters here, so please bear with me on this question, I know very well that there is a difference in the defintion of mitochondrial dna and nucleus dna, I believe I know, but would appreciate an explanations as to the difference in the 2 scientific methods used to determine origin, please keep it simple Im not the lightest bulb in the pack on this issue. Thank you.

 

[Jayelles]

Well I'm not a scientific expert either but this is what I understand.

Mitochondrial DNA is written as MtDNA and it is found in hairs. It is passed through the maternal side of the family so if a hair was found, scientist could say that it could belong to me or any of my children - but that is all. There were huge studies done on MtDNA and because they were clinical studies, they had a lot of data about the donors of the MtDNA. For this reason, they were able to make a database with this information and that database includes details about race. This means that if they find a hair at a crime scene, they can look up the database and make an educated guess at the race of the hair's owner. In the trial of David Westerfield, some blonde hairs were found in his RV. Experts were able to say that some of these hairs had come from Brenda vanDam or one of her three children. However, another hair, they said was Asian in origin. This was puzzling - because it was blonde and Asians are not blonde. It transpired that David Westerfield had a girlfriend who was Asian but who had died her hair blonde!

Nuclear DNA is found in blood, skincells etc and it is pretty unique to individual people. You will inherit some DNA information from your parents and so scientists can tell if two people are likely to be related. They can also tell sex from nuclear DNA but not race. This is because they would need to define race! The mtDNA database is different because they have such a huge bank of data inlcuding race.

 

[terralee]

Thank you for your explanation, I appreciate that you kept it simple, I find dna such a powerful tool,but a bit complicated, unless of course you get the drift lol

 

[BlueCrab]

In addition to hair, other popular sources of mitochondrial DNA are bones and teeth.

 

[Gidgette]

Well I'm not a scientific expert either but this is what I understand.

Mitochondrial DNA is written as MtDNA and it is found in hairs. It is passed through the maternal side of the family so if a hair was found, scientist could say that it could belong to me or any of my children - but that is all. There were huge studies done on MtDNA and because they were clinical studies, they had a lot of data about the donors of the MtDNA. For this reason, they were able to make a database with this information and that database includes details about race. This means that if they find a hair at a crime scene, they can look up the database and make an educated guess at the race of the hair's owner. In the trial of David Westerfield, some blonde hairs were found in his RV. Experts were able to say that some of these hairs had come from Brenda vanDam or one of her three children. However, another hair, they said was Asian in origin. This was puzzling - because it was blonde and Asians are not blonde. It transpired that David Westerfield had a girlfriend who was Asian but who had died her hair blonde!

Nuclear DNA is found in blood, skincells etc and it is pretty unique to individual people. You will inherit some DNA information from your parents and so scientists can tell if two people are likely to be related. They can also tell sex from nuclear DNA but not race. This is because they would need to define race! The mtDNA database is different because they have such a huge bank of data inlcuding race.

Not exactly accurate. While his girlfrined was of Asian decent, her hair was dark as I remember seeing her on the stand. However her 16 year old daughter did dye her hair blond.

Gidgette.