Arripis georgianus See Ruff

Artificial selection The process wherein a human breeder chooses which of the progeny of a plant or animal should survive and reproduce. The long-term results of such selection are preferred *breeds or *races. It was CD who first noted the similarity between such selection and the process he called *natural selection.

In fact, the two processes differ only when seen from our perspective as 'selectors'. From the selectee's (e.g. a *Goldfish's) point of view, we are as much part of its environment as, say, its *parasites. Thus, we can also conceive artificial selection as being, from the selectee's point of view, a way of establishing itself in a new niche: the material culture that humans create (including aquaria in pet shops).

Ascension Island A small island in the Southeastern Atlantic, 1290 km to the northwest of *Saint Helena Island, visited by the Beagle on July 19-23, 1836. CD took the opportunity for studying the geology of Ascension Island, but does not appear to have sampled its marine life.

Later, however, CD did comment on the fishes of Ascension Island: Fish of Teneriffe. St. Helena & Ascension most species like & identical with S. America. & many very close:5 see full paper.6 L'Institut 1838. p. 338 (Notebook E, p. 406; n. 5 refers to Valenciennes (1838a), p. 338; 6 to Valenciennes (1838b), i.e. a summary ofValenciennes (1837-44)).

According to Edwards (1990, p. 45), Ascension Island has a total of72 species ofbottom-dwelling neritic fish, with the following affinities: widespread warm Atlantic species 24; Western and Central Atlantic 21; Central Atlantic 16; Eastern and Central Atlantic 4; *endemic species: 7 (i.e. 10%, similar to the percentage of endemic fishes in the *Galapagos).

Assuming that 'most' means over 50%, it may perhaps be argued that, indeed, most species [of Ascencion are] like & identical with S. America -but this may stretch CD's description too far.

Ascidians See Seasquirts.

0 0

Post a comment