With its thin body and skeleton, long jaw resembling that of a swordfish and its sharp teeth, the needlefish has undergone not the slightest change in 95 million years. This unchanging nature, seen in all living species in the fossil record, is known as "stasis" and represents one of the main problems confronting Darwinists. Peter Williamson from Harvard University sums up this state of affairs, which is a most unexpected one for Darwinists: "The principal problem is morphological stasis. A theory is only as good as its predictions, and conventional neo-Darwinism, which claims to be a comprehensive explanation of evolutionary process, has failed to predict the widespread long-term morphological stasis now recognized as one of the most striking aspects of the fossil record." (Peter G. Williamson, "Morphological Stasis and Developmental Constraint: Real Problems for Neo-Darwinism," Nature, Vol. 294, 19 November 1981, p. 214.)