The question regards a paper by W.S. Grant and R.W. Leslie, J. Zoology,
London, 1993, 231:465-485. In this paper the authors analyze allozyme
hetreogeneity among 6 species of Lophius using cladistics to arrive at a
postulated phylogeny for the genus. Lophiomus is used as the outgroup.
Geological events are used to explain the distribution of the seven
species of Lophius, and this gets to the heart of my question. On page
481 of the paper, Grant and Leslie suggest that the 'first split in the
ancestral tropical Atlantic population of Lophius followed the separation
of the South American and African Plates'. The paper previously stated
that the ancestral tropical Atlantic population did not exist before 27
my. I don't understand how the separation of the population followed an
event (separation of the S.American and African plates) which occurred
before the popultaion existed. My understanding is that by the time the
ancestral population had evolved (27my), the two plates were almost
completely separated and in their present positions.
How could plate separation result in a vicariant event resulting in the
spliiting of ther ancestral Lophius population?
Please e-mail responses to ellison at csulb.edu
| | Homer O. Ellison, ellison at csulb.edu | |
| | Department of Biological Sciences | |
| | California State University, Long Beach | |
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