Are we genetically related?

Question

Has there ever been a study to find if out humans from various areas of the world have a common gene....In other words, it would appear we came from the first humans.(Adam and Eve)

Answer 1

Yes!! (Great question!) Google "Mitochondrial Eve" (or "Y-chromosome Adam") and you will find many links to this exact question. But here's a summary:

There is DNA in the mitochondria of human cells (outside the nucleus where your genes are). This DNA is passed down directly from mother to children ... dad's mitochondrial DNA does not get passed down or combined with mom's.

This means that the DNA is passed down matrilinealy (mother to daughter to grandaughter, etc.), without cross with the father. So it is mostly unchanged ... except for mutations (basically 'typos' in the copying) that happen at a known rate (so many every hundred generations).

Based on the current variation in the mitochondria of women from all regions of the world, we can matrilineally trace the most recent common ancestor (MRCA) of all humans alive today. Geneticists sometimes call this common female ancestor "mitochondrial Eve."

Based on current genetics, and the rate that random transcription errors enter into mitochondrial DNA, we can calculate that Mitochondrial Eve lived about 150,000 years ago.

We can also do the same for men using the Y-chromosome ... as this is always passed from father to son without any mixing from mom (females don't have a Y-chromosome). We call the most recent patrilineal common ancestor "Y-chromosome Adam."

Y-chromosome Adam is estimated to have lived between 60,000 and 90,000 years ago.

So note that Y-chrom Adam and Mito- Eve did not know each other ... they were separated by at least 30,000 years. (In fact, Y-chrom. Adam may have been a descendant of Mitochondrial Eve.)

And also don't get confused that Mitochondrial Eve was the "first woman". There were many other women alive in her time ... just all of their bloodlines ended up dying out at some point before now (some female descendant only had sons, who could not pass on her mitochondrial DNA). This is only about the most recent common ancestor (MRCA) as determined by the current distribution of mitochondrial DNA.

Oh, and both Mitochondrial Eve and Y-chromosome Adam were what we would now call "human" (Homo sapiens has been around for about 200,000 years.)

(P.S., this is completely unrelated to Lucy, who lived about 3.2 million years ago ... *much* earlier than Mitochondrial Eve or Y-chromosome Adam. Lucy was not Homo sapiens, but Australopithecus afarensis, an ancestor species to Homo sapiens. It is extremely unlikely that we are ancestors of that *individual* ... but we are probably descended from another of her species.)

All this sounds wild, but it is well backed up by genetics. Please check out my sources, and do a Google for *lots* more links.

Answer 2

To answer your question, though, mitochondrial DNA is highly conserved. That is to say, it is so densely packed with funtional bits (genes and RNAs) that there is little left over that is not used. Because of this, and because of the importance of having functional mitochondria to be able to survive, changes in mitochondrial DNA enter the population very rarely.

Because of this, if a stable change occurs in mDNA, it tends to stay there and be passed on (in a matrilinear fashion...through the mother).

These changes, when viewed throughout and between populations of people, can show the racial (I hate that word with respect to genetics...it causes a lot of trouble) background of that person. Charts have been drawn showing the percentage relationship between gerographical populations. This study was also done on prehistoric anthropoid remains to show how the modern populations relate to each other and to these ancient relatives of ours. They found remains from a female who they called Lucy who seemed to be from among the population that was the ancestor of all modern races.

Answer 3

I think it would depend on what type of gene they are looking for. What i thought was interesting that in Europe a family has a gene in which they cannot get high cholestrol.. I think its eveoultion. Seeing that we now have more food and we dont need slow metabolisms having not to worry about chostrol is a pretty cool thing