Home Page Science Frontiers

No. 35: Sep-Oct 1984

Issue Contents

Other pages

Other Interesting Sites











Getting The Pouch Right

When we think of kangaroos hopping about Australia (which isn't very often), we know that all baby kangaroos are safely "buckled in" their mothers' pouches -- nature's own vehicle restraint system. How fortunate it is that kangaroo pouches open at the top; otherwise, little kangaroos would be falling out all over the place. While some marsupials have pouches opening "up" or "forward" in quite a few others evolution got the directions for pouch manufacture reversed. The koala, the wombat, the thylacine, and the marsupial mole all have backward-opening pouches. Obviously, a forward-opening pouch on the mole would act like a dirt scoop, to the great inconvenience of any occupants. On the other quadrupeds, the backwardopening pouch may protect the young from branches and vegetation.

(Marshall, Jeremy H.; "Directional Pouches," Nature, 309:300, 1984.)

Comment. This is an example of the socalled Problem of Perfection, where life seems marvelously attuned to its environment; that is, "fittest." Somewhere among the millions of species alive today, there must be one out-and-out failure. Of course, if full-scale nuclear war breaks out, we will know that evolution did make at least one mistake!

Nature's cartoon of a kangaroo with a wrong-way pouch. Evolution gone wrong! Nature's cartoon of a kangaroo with a wrong-way pouch.

From Science Frontiers #35, SEP-OCT 1984. 1984-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987