Historical patterns of avian taxonomy -- 6

In this plot, data points are omitted, and only the smooth curve fits are plotted. The Y-axis is the number of citations (taxa described) per year, expressed as the fourth root. (^0.25). [See discussion below] It represents the number of species described. The X-axis is the year, and the period from 1790 to 1815 is delimited by the vertical dashed lines.

Three lines are displayed, for Great Britain, France, and Germany. I categoriesed as well as I could the country of publication for the taxa described during this period. It must be noted that no "Germany" existed during this time - but for the ease of analysis I treated any publication from a location that would be in present day "Germany" as being German.

Great Britain, France, and "Germany" were the top three countries publishing taxa during this period. Sweden actually belongs in the list, but has a very high showing very early, then virtually disappears from the list.

Only "Germany" shows any decline during the period of the "gap".

I have reservations and skepticisms about this plot and the possible interpretations that it suggests. It must be noted that the numbers here are small, and though not plotted, the data points include a good bit of scatter.


I have used the somewhat unusual data transformation of taking the fourth root of the data. The fourth root transformation is very much like taking the log. However, it treats the zero values (which are frequent here) more conveniently. (the log(0)=negative infinity; 0^0.25=0). It is best thought of as the equivalent of a log transformation.

Comments&Suggestions to Data Steward

Alan P. Peterson, M.D.
POB 1999
Walla Walla, WA 99362-0999

Last updated 2000.04.23