Saturday’s New York Times had a story by Sam Roberts about a newly released Census Bureau study of the frequency of surnames in the U.S. The Times story was mainly about the names at the top of the list, and especially the increasing prominence of Hispanic names (Garcia and Rodriguez have made it into the […]

Above: A throbbing, wheeling mob of several thousand restless starlings, near a strip mall in Clayton, North Carolina, 27 October 2007. Below: Snow geese on maneuvers near Ashburn, Missouri, 12 November 2004.

In the 1930s, Edmund Selous argued that flocking behavior could be explained only through some form of animal ESP: “thought transference” was the only […]

When is a tree (large, woody plant) not a tree (connected acyclic graph)?

This has something or other to do with the topic of the previous post.
(The tree (?) is a crepe myrtle near the campus of North Carolina State University in Raleigh.)

David Aldous asked me that question over lunch one day. I didn’t have an answer, so he explained: In the simplest model of human genetics, you get half your genes from each parent, a fourth from each grandparent, and so on. Thus the fraction of your genes contributed by each member of the nth generation […]

The spirals and whorls seen in sunflowers, pine cones and various other plant structures have long held a special fascination for mathematicians and for biologists with a mathematical bent. After all, you can find Fibonacci numbers in those natural patterns—who could resist? But it’s not just Golden Ratio mysticism that accounts for this interest. More […]