--- In
cybalist@yahoogroups.com, "Davius Sanctex"
<gruposdavius@...> wrote:
>
> PCA (Principal Component Analysis) applied to the genetic
variances in the ocurrence of certain gens, reveals that they exist
4 main factors to explain genetical diversity in Europe:
The conclusions seem to be interesting but I don't understand how
PCA works here. The PCA technique decomposes a multicomponent data
field in spatial patterns (Empirical Orthogonal Functions/EOFs) and
associated principal components (PCs) -- series that modulates the
EOFs. The PCs should be *series* of something (e.g. frequency
occurrences of genetic features), not *maps*! Are the PC series
genetic fingerprints of historically distinct populations? How many
genes and spatial points were used in this PCA? (We should know
these numbers in order to assess the statistical significance of the
results.)
Roxana.