... Science Frontiers ONLINE No. 87: May-Jun 1993 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Is caddy a mammal?" Caddy" is short for Cadborosaurus , the speculative sea animal seen rather frequently off the British Columbia coast and as far south as Oregon. Professor P. LeBlond, University of British Columbia, recently presented a paper on Caddy at a joint meeting of the Canadian and American Societies of Zoology. Of all the supposed sea serpents, Caddy seems closest to respectability. Not only are there many sightings on record, but the remains of a 3-meterlong carcass of an apparent juvenile specimen of Caddy was discovered in the stomach of a sperm whale. Adult Caddys are about 7 meters long. "The descriptions [of Caddy] are generally similar. They suggest a long-necked beast with short pointed front flippers, a horse-like head, distinct eyes, a visible mouth and either ears or giraffe-like horns. Often Caddy is described as having hair like a seal, and sometimes a mane along its neck." Most interesting is Caddy's body hair, which implies a mammal rather than a reptile. But if it is a mammal, how does it get air, since it surfaces so rarely? Some have suggested that the giraffe-like horns are snorkels! But E. Bousfield, a colleague of LeBlond, thinks that the tubercules reported along the animal's back might be gill-like tissues that would allow a mammal to extract oxygen from seawater! With so ...

... Science Frontiers ONLINE No. 8: Fall 1979 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Convergent evolution or chance look-alikes Why should caddis fly larvae and a species of aquatic snail look alike? Mimicry is rather common in nature for it often confers some sort of advantage to one or both of the species in the turmoil of evolutionary pressures. Or so the theory goes. Most examples of convergent evolution involve closely related species. In the present case, though, the species are in different phyla. The caddis fly larva builds its snail-like shell by cementing grains of sand together with a silk-like secretion, while the snail's shell is a calcareous excretion. One would expect a strong advantage to be conferred on one or the other species, especially in the matter of predation. Using brook trout as predators, how ever, proved perplexing, for the trout would eat only the snails, avoiding the carbon-copy larvae. (Berger, Joel, and Kaster, Jerry; "Convergent Evolution between Phyla...." Evolution, 33:511, 1979.) Comment. This is a remarkable case of mimicry. One wonders how the caddisfly larvae know exactly what snails look like, and how the unique shell constructing methods were coded into its genes by evolution. Or did the snail emulate the larvae? From Science Frontiers #8 , Fall 1979 . 1979-2000 William R. Corliss ...