MrDarwin

Interesting article suggesting that the evolution of new organs, which creationists suggest is a problem for evolution, may not be such a big problem after all:

UC Riverside Study Suggests Placentas Can Evolve In 750,000 Years Or Less; Guppy-Like Fish Help Fill In The Gaps In The Evolution Of Complex Organs

Principia

Science 2002 Nov 1;298(5595):1018-20

Independent origins and rapid evolution of the placenta in the fish genus Poeciliopsis.

Reznick DN, Mateos M, Springer MS.

Department of Biology and Center for Conservation Biology, University of California, Riverside, CA 92521, USA. david.reznick@ucr.edu

The evolution of complex organs is a source of controversy because they require the contributions of many adaptations to function properly. We argue that placentas are complex, that they have evolved multiple times in Poeciliopsis, and that there are closely related sister taxa that have either no placentas or intermediate stages in the evolution of a placenta. Furthermore, placentas can evolve in 750,000 years or less, on the same time scale as suggested by theoretical calculations for the evolution of complex eyes. Independent origins of such complexity, accompanied by sister taxa that either lack or have intermediate stages in the evolution of the trait, present an opportunity to study the evolution of novelty and complexity from a comparative, evolutionary perspective.