with the origin of whales remains a peren- 

 nial favorite. God's taunt to Job might be 

 sounded again: "canst thou draw out 

 leviathan with an hook?" (The biblical 

 leviathan is usually interpreted as a croco- 

 dile, but many alternative readings favor 

 whales.) 



Every creationist book on my shelf 

 cites the actual absence and inherent in- 

 conceivability of transitional forms be- 

 tween terrestrial mammals and whales. 

 Alan Haywood, for example, writes {Cre- 

 ation and Evolution, Triangle Books, 

 1985): 



Darwinists rarely mention the whale be- 

 cause it presents them with one of their most 

 insoluble problems. They believe that some- 

 how a whale must have evolved from an or- 

 dinary land-dwelling animal, which took to 

 the sea and lost its legs.. . . A land mammal 

 that was in process of becoming a whale 

 would fall between two stools — it would not 

 be fitted for life on land or at sea, and would 

 have no hope of survival. 



Duane Gish, creationism's most ardent 

 debater, makes the same argument in his 

 more colorful style {Evolution: The Chal- 

 lenge of the Fossil Record, Creation Life 

 Publishers, 1985): 



There simply are no transitional forms in 

 the fossil record between the marine mam- 

 mals and their supposed land mammal an- 

 cestors.... It is quite entertaining, starting 

 with cows, pigs, or buffaloes, to attempt to 

 visualize what the intermediates may have 

 looked like. Starting with a cow, one could 

 even imagine one line of descent which pre- 

 maturely became extinct, due to what might 

 be called an "udder failure." 



n-> '^ 



^-'^X^ 



The most "sophisticated" (I should re- 

 ally say "glossy") of creationist texts, Of 

 Pandas and People, by P. Davis, D. H. 

 Kenyon, and C. B. Thaxton (Haughton 

 Publishing, 1989), says much the same, 

 but more in the lingo of academese: 



The absence of unambiguous transitional 

 fossils is strikingly illustrated by the fossil 

 record of whales.. . . If whales did have land 

 mammal ancestors, we should expect to find 

 some transitional fossils. Why? Because the 

 anatomical differences between whales and 

 terrestrial mammals are so great that innu- 

 merable in-between stages must have pad- 

 dled and swam the ancient seas before a 

 whale as we know it appeared. So far these 

 transitional forms have not been found. 



Three major groups of mammals have 

 returned to the ways of distant ancestors in 

 their seafaring modes of life (while 

 smaller lineages within several other 

 mammalian orders have become at least 

 semiaquatic, often to a remarkable degree, 

 as in river and sea otters): the suborder 

 Pinnipedia (seals, sea lions, and walruses) 

 within the order Camivora (dogs, cats, and 

 Darwin's bears among others); and two 

 entire orders — the Sirenia (dugongs and 

 manatees) and Cetacea (whales and dol- 

 phins). I confess that I have never quite 

 grasped the creationists's point about in- 

 conceivability of transition — for a good 

 structural (although admittedly not a phy- 

 logenetic) series of intermediate anat- 

 omies may be extracted from these groups. 

 Otters have remarkable aquatic abilities, 

 but retain fully functional limbs for land. 

 Sea lions are clearly adapted for water, but 

 can still flop about on land with sufficient 



^^^^C^ 



"/ love my kids, but these Mother's Day visits do have their drawbacks. 



dexterity for ice floes, breeding grounds, 

 and circus rings. 



But I admit, of course, that the transi- 

 tion to manatees and whales represents no 

 trivial extension, for these fully aquatic 

 mammals propel themselves by powerful, 

 horizontal tail flukes and have no visible 

 hind limbs at all — and how can a lineage 

 both develop a flat propulsive tail from the 

 standard mammalian length of rope and 

 then forfeit the usual equipment of back 

 feet so completely? (Sirenians have lost 

 every vestige of back legs; whales often 

 retain tiny, splintlike pelvic and leg bones, 

 but no foot or finger bones, embedded in 

 musculature of the body wall, but with no 

 visible expression in external anatomy.) 



The loss of back legs and the develop- 

 ment of flukes, fins, and flippers by whales 

 therefore stands as a classic case of a sup- 

 posed cardinal problem in evolutionary 

 theory — the failure to find intermediary 

 fossils for major anatomical transitions or 

 even to imagine how such a bridging form 

 might look or work. Darwin acknowl- 

 edged the issue by constructing a much 

 criticized fable about swimming bears, in- 

 stead of presenting any evidence at all, 

 when he tried to conceptualize the evolu- 

 tion of whales. Modem creationists con- 

 tinue to use this example and stress the ab- 

 sence of intermediary forms in this 

 supposed (they would say impossible) 

 transition from land to sea. 



Goethe told us to "love those who yearn 

 for the impossible." But Pliny the Elder, 

 before dying of curiosity by straying too 

 close to Vesuvius at the worst of aU pos- 

 sible moments, urged us to treat impossi- 

 bility as a relative claim: "How many 

 things, too, are looked upon as quite im- 

 possible until they have been actually ef- 

 fected." Armed with such wisdom of 

 human ages, 1 am absolutely delighted to 

 report fliat our usually recalcitrant fossil 

 record has come through in exemplary 

 fashion. During the past fifteen years, new 

 discoveries in Africa and Pakistan have 

 added greatly to our paleontological 

 knowledge of the earliest history of 

 whales. The embarrassment of past ab- 

 sence has been replaced by a bounty of 

 new evidence — and by the sweetest series 

 of transitional fossils an evolutionist could 

 ever hope to find. Truly, we have met the 

 enemy and he is now ours. Moreover, to 

 add blessed insult to the creationists's in- 

 jury, diese discoveries have arrived in a 

 gradual and sequential fashion — a little bit 

 at a time, step by step, from a tentative hint 

 fifteen years ago to a remarkable smoking 

 gun early in 1994. Intellectual history has 



10 Natural History 5/94 



