Regular readers may have noticed that one of my passions is to measure snail shells. I have written about the variability of shell dimensions on several occasions, for example here. Naturally, I have pages and pages of data waiting to be analyzed and made sense out of.
Today, I entered a set of measurements from 2004 into the computer. They belong to a sample of 131 shells of an Albinaria species that we had collected in 2002 in Turkey. Here is the histogram for shell heights.
I haven't run any statistical tests, but the distribution looks roughly normal. The 2 specimens making up the right-hand tail seem to be outliers. However, the relative coefficient of variation* is 5.8%, which is quite ordinary for shell heights of tall-shelled land snails. So those 2 shells actually lie within the expected range of variation for a sample of this size.
The 2nd entry in this series is here.