Montag, 14. Februar 2011

Triangulation 1 ( Reflections )

My tyrolean cousin 

Each comparison generates its own visual form. Genetic ones don't need a spatial background like a measure scale, but something inevitable - time! And this form seems shaped to me like a ladder or a triangle. The most simple way of comparing works with mitochondria, since they are small, stable and mutate very slowly. One foot of that ladder now is defined by the revised full genome raw file of the Cambridge Reference Sequence, the rCRS. Before there has been a Yoruba sequence and others, since Anderson extracted the first sequence in 1981.
The third part of that triangle is the MRCA, the most recent common ancestor and depending on the amount of mutations he has to be placed further back in time.
Here is a first triangle, combining the rCRS with cousin clade - H11a2. The listed mutations correspond to the usual phylogenetic tree ( ). The faces belong to a series of drawings, tying various women of all parts of the world together in a vertical social network ( ) .

For a better understanding I laid the ladder aside, so the MRCA is now left hand instead of the top. But still each mutation – or better haplogroup – functions like a rung of a ladder.

I started to mistrust the former age estimations. H11 has been considered to be older than 40000 years, probably due to the fact, that each mutation on the Hyper Variable Region 1 was handled with a rate of 10000 years. In this clade you usually find four mutations, while most of the other about 40 subclades of haplogroup H can only be defined by a Coding Region mutation - ergo! The appearance of H11 in Siberia supported this time estimation.

The more mutations you find, the further back in time your last common ancestor must be considered. In the case of H11 you only have to go back until H, then turn aside on the branch of H11. To reach my own haplogroup K1b2a or that of my distant tyrolean cousin, the iceman from the Ötztal, we have to pass H and go back until R, about 60000 years, before we come to K via U and U8b.

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