In article <01IE8KW50XMA00DWG2 at RL0002.RULIMBURG.NL>, F.Schaap at FYS.UNIMAAS.NL writes:
>Current times reported for the rat/mouse divergence range from 10-25 mya. Who
>knows which value is most reliable?
based on paleontology, a date of 12 Myr is usualy considered reasonnable.
Studies based on molecular clocks have pushed it back as far as 35 Myr,
and rarely obtain dates below 20 Myr.
This is a big difference, and I don't think one can simply tell which value
is most reliable. I tend to use the 12-14 Myr date, although a molecular
evolutionist, because I don't think much of molecular clocks, especialy not
in rodents.
some paleontological refs :
Jacobs, L. L., and Downs, W. R. (1994). The evolution of
murine rodents in Asia. In Tomida, Y., Li, C., and Setoguchi, T.
(Eds.), "Rodent and lagomorph families of Asian origin and
diversification", Tokyo, vol. 8, pp. 149-156.
Jacobs, L. L., Flynn, L. J., and Downs, W. R. (1989). Neogene
rodents of southern Asia. In Black, C. C., and Dawson, M. R.
(Eds.), "Papers on fossil rodents in honor of Albert Elmer
Wood", Nat. Hist. Mus. Los Angeles County, Los Angeles,
Science Series n¡ 33, pp. 157-177.
Jacobs, L. L., Flynn, L. J., Downs, W. R., and Barry, J. C.
(1990). Quo vadis, Antemus? The Siwalik muroid record. In
Lindy, E. H., Fahlbusch, V., and Mein, P. (Eds.), "European
Neogene Mammal Chronology", Plenum Press, New York, pp.
573-586.
some molecular refs :
O'hUigin, C. and Li, W.H. (1992) The molecular clock tiks
regularly in muroid rodents and hamsters. J. Mol. Evol. 35: 377-
384
Janke, A., Feldmaier-Fuchs, G., Thomas, W.K., Von Haesler,
A. and Paebo, S. (1994) The marsupial mitochondrial genome
and the evolution of placental mammals. Genetics 137: 243-256
Frye, M.S. and Hedges, S.B. (1995) Monophyly of the order
Rodentia inferred from mitochondrial DNA sequences of the
genes for 12S RNA, 16S RNA, and tRNA-Valine. Mol. Biol.
Evol. 12: 168-176
hope this helps,
Marc
_________________________________________________________________
Marc Robinson
UMR CNRS 5558 "Biometrie, Genetique, et Biologie des Populations"
Universite Claude Bernard Lyon 1
43, boulevard du 11 novembre 1918
69622 Villeurbanne cedex
France
tel : 04 72 44 80 00 - poste 41 43
fax : 04 78 89 27 19
from abroad : replace 04 with 33 4
e-mail : robinson at biomserv.univ-lyon1.fr
