| From: goose girl | 26/05/2000
18:49:00 |
| Subject: Twins DNA |
post id:
75340 |
| Hi everyone, The other day I heard on the radio some woman say that twins have identical DNA. I didn't think that they had exactly the same DNA. The woman was talking about this in regard to identifying a criminal through their DNA. She said that seeing as though the suspected perpetrator didn't have a twin, then the DNA proved that he was indeed guilty. :) | |
| From: Min-Zhao Lee (TRO) | 26/05/2000
18:52:00 |
| Subject: re: Twins DNA |
post id:
75343 |
| Before I go... There are two kinds of twins: fraternal, and identical. Identical twins arise from the splitting of the zygote (that's the correct terminology, isn't it?), while fraternal twins arise from different eggs. Identical twins WILL have the same DNA if subsequent mutations do not occur. | |
| From: newbie | 26/05/2000
18:52:00 |
| Subject: re: Twins DNA |
post id:
75344 |
| I THINK identical twins have the
same DNA, but not 'different' twins | |
| From: Drues | 26/05/2000
18:55:00 |
| Subject: re: Twins DNA |
post id:
75347 |
| Depends on the kind of twins
involved. I dunno the two types of twins, but I do know twins arising from
the one fertilised egg splitting in two have identical DNA. If you want to delve into the pedantic, these twins' DNA would become more and more un-alike(?) as they age due to telomeric DNA degredation and natural mutations. DNA profiling uses little DNA "scissors" that cut the molecule at "recognition sites" of between 3 and 8 nucleotides (the bricks of DNA). By measuring the size of the DNA fragments obtained, this gives a profile of the person which can be used for whatever. The twin's profile will be identical, and the profile between you and me will be very different. I think the probability is somewhere in the ball park of an identical match in one in 20 billion. This process is called RFLP - Restriction Fragment Length Polymorphisms. | |
| From: DV (Avatar) | 26/05/2000
18:57:00 |
| Subject: re: Twins DNA |
post id:
75348 |
| Note that even "identical" twins
with identical DNA will not be identical: there are post-conception
factors that can affect appearance (womb-space, nutrition
etc.) | |
| From: cerian | 26/05/2000
19:07:00 |
| Subject: re: Twins DNA |
post id:
75358 |
| right and left
handedness...... ;-) | |
| From: DV (Avatar) | 26/05/2000
19:10:00 |
| Subject: re: Twins DNA |
post id:
75360 |
| My mind is not closed on that
one...but I maintain that if (as Lord Robert Winston stated) it is so that
a post-conception late split of the embryo can result in one leftie and
one rightie, then it is not true that handedness is purely genetic.
| |