On Smiley Faces

Biological Evolution
Biodiversity
Nature
Edward Hessler

Ed Scholer and Tim Laman of the Cornell Laboratory of Ornithology have found evidence supporting the existence of a new species of the Superb Bird-of-Paradise (Lophorina superba).

This announcement in Cornell Lab eNews (July 2017) includes a short film of the dance of the original Superb Bird-of-Paradise.  As it dances, the bird transforms into the shape of a "psychedelic smiley face." The film describes and shows how modified feathers involved in this astonishing transformation create this pattern. Four different groups of feathers are involved.

You may read about the new species of the Superb Bird-of-Paradise here. The researchers found that the courtship dance differs, the vocalizations are different and the shape of the displaying males is different. In addition, another group of researches have found differences in DNA. This is an example of how scientists work, seeking corroborating evidence.

The essay includes still photographs of the two species showing them in full display. The raised cape of the western male is crescent shaped. The raised cape of the more widespread Superb Bird-of-Paradise has an oval shape.

The behavior is a classic example of female choice sexual selection, a special case of natural selection. Sexual selection was first proposed by Charles Darwin in The Origin of Species (1859) and developed in The Descent of Man and Selection in Relation to Sex (1871).

And what a radical idea it was!