What does it mean to "share DNA"?

[Klax (The only thing that matters is faith expressed in love.)]

I think the original question leads to a male geneticist’s chat up line. ‘Can ah share some DNA with you?’

[03Cobra (Vance)]

A simple view is that the extent to which we “share DNA,” or have identical DNA, with another person is a measure of how closely we are related (i.e., have common ancestors).

55% of my DNA matches my brother’s exactly. And my y-chromosome matches hundreds of guys named Talley or Tally or Tolley.

[Terry_Sampson]

@03Cobra

A simple view is that the extent to which we “share DNA,” or have identical DNA, with another person is a measure of how closely we are related (i.e., have common ancestors).

???

• “Humans and chimps share a surprising 98.8 percent of their DNA.”

So how many chimps do you have among your DNA matches?

[03Cobra (Vance)]

No chimps have shown up on my reports yet. I think there are at least a couple of reasons:

1. Few, if any, chimps have purchased the tests and
2. Common ancestors, if any, are so far back in time that the shared DNA doesn’t rise to the reporting level.

Are there any chimps in your matches?

I am no expert in this. I just monkey around with it some.

[T_aquaticus]

@03Cobra

No chimps have shown up on my reports yet. I think there are at least a couple of reasons:

1. Few, if any, chimps have purchased the tests and
2. Common ancestors, if any, are so far back in time that the shared DNA doesn’t rise to the reporting level.

They have their own sets of tests for relatedness and migration history.

Much like humans, chimpanzees occupy diverse habitats and exhibit extensive behavioural variability. However, chimpanzees are recognized as a discontinuous species, with four subspecies separated by historical geographic barriers. Nevertheless, their range-wide degree of genetic connectivity remains poorly resolved, mainly due to sampling limitations. By analyzing a geographically comprehensive sample set amplified at microsatellite markers that inform recent population history, we found that isolation by distance explains most of the range-wide genetic structure of chimpanzees. Furthermore, we did not identify spatial discontinuities corresponding with the recognized subspecies, suggesting that some of the subspecies-delineating geographic barriers were recently permeable to gene flow. Substantial range-wide genetic connectivity is consistent with the hypothesis that behavioural flexibility is a salient driver of chimpanzee responses to changing environmental conditions. Finally, our observation of strong local differentiation associated with recent anthropogenic pressures portends future loss of critical genetic diversity if habitat fragmentation and population isolation continue unabated.
Recent genetic connectivity and clinal variation in chimpanzees | Communications Biology

[03Cobra (Vance)]

I suppose I should said that chimps haven’t purchased the same tests and I have not joined the same data bases.

[jpm (Phil McCurdy)]

It would be interesting to see what happens if you send a chimp’s dna into 23 and me or Ancestory.com. I bet someone has done it. Although, probably would just an inadequate sample reply.

[T_aquaticus]

@jpm

It would be interesting to see what happens if you send a chimp’s dna into 23 and me or Ancestory.com. I bet someone has done it. Although, probably would just an inadequate sample reply.

It appears that 23 and me uses DNA chip technology.

In order to be genotyped, the amplified DNA is “cut” into smaller pieces, which are then applied to our DNA chip (also known as a microarray), a small glass slide with millions of microscopic “beads” on its surface. Each bead is attached to a “probe," a bit of DNA that matches one of the genetic variants that we test. The cut pieces of your DNA stick to the matching DNA probes. A fluorescent label on each probe identifies which version of that genetic variant your DNA corresponds to.
https://customercare.23andme.com/hc/en-us/articles/202904610-How-Does-23andMe-Genotype-My-DNA-

I would suspect that they use stringent conditions for DNA binding, so if the DNA doesn’t match the probes on the chip then you will not get a result. If the chimp DNA is identical to a human variant in the specific regions they are looking at then you would get a result.

[Dale (evolutionary providentialist)]

@03Cobra

I just monkey around with it some.

Groan.  

[Terry_Sampson]

@03Cobra

Are there any chimps in your matches?

None known yet, but I’m keeping an eye on some mischievous knuckle-draggers who’ve been showing up uninvited from time to time.