Fróðskaparrit - 01.01.1979, Síða 58

66
Anthropological and Genetic Studies of the Faroese
ably present in individuals of more diverse family background,
reflects itself in rather different pattern type frequencies. How-
ever this hypothesis fails to explain why the difference should
be in opposite directions in males and females.
Investigation of another important dermatoglyphic feature,
total ridge count, also yielded interesting results. Arches, the
simplest pattern type, have no ridge count, but in loops and
whorls it is the number of ridges crossed by a straight line
joining the pattern centre or ‘core’ to a point known as the
triradius, Figure 3. Triradii occur wherever three opposed
ridge systems meet. A loop having one triradius has a single
ridge count whereas whorls have two counts. Ridge breadth
and therefore number per unit distance varies slightly between
individuals but to a large extent ridge count is a measure of
pattern size. An individual’s total ridge count is the sum of
the ridge counts on all ten fingers (in the case of whorls only
the larger of the two counts is used). The mean total ridge
count was calculated for the samples of Faroese males and
females and for the regional and mixed origin sub-samples.
The results are given in Table 4. The male mixed origin group,
having a considerably lower mean total ridge count, was again
distinct from the regional groups. In the females the Northern
group had the lowest mean total ridge count whilst the mixed
origin group had a value intermediate between those for the
Central and Southern groups. Compared to other populations
the Faroese values are low, particularly so for the females
with a value of 105.8 reflecting their high arch frequencies.
Males have in general larger fingers and larger patterns than
females and consequntly have a higher mean total ridge count,
in the case of the Faroese males 123.7. This is similar to the
value of 123.9 given by Berry and Muir (1975) for Shetland
but considerably less than the value of 139.7 for Swedish
males (Book 1957), or 145.2 for English males (Holt 1968).
The Pigmentation Survey
The pigmentation of the hair, skin and eyes is one of the