LYNCH89@irlearn.bitnet (John Lynch) (06/02/89)
A small query .... what is the current belief re the minimum sample size required to adequately sample a population for isozyme analysis ??? John
LYNCH89@irlearn.bitnet (John Lynch) (06/03/89)
I presume Anns comment was directed at me (!) so here goes...... The problem under investigation is the appearence of hybrids between two sympatric deer species here in Ireland (Cervus elaphus & C. nippon). Hybrids are reported to occur in one locality, but not in another (Why?). Within the locality with hybrids a number of C.e.-like and C.n-like animals occur, with a number of obvious hybrids. Immunological evidence lead one observer to state that NO pure C.e. or C.n exist in the area due to complete introgression. Work by myself using the technique of canonical variate analysis of skulls showed that pure C. nippon DO exist, and that these animals are as pure as those from the area where no hybrids exist. An analysis of the Cervus elaphus specimins has just begun. The next phase of the work aims to examine three points ; (1) Behavioural observation of the putative 'pure' populations to examine the degree of behavioural interaction between the species, particularly during the mating season, (2) Morphological examination to 'map' the morphs which occur in the study areas - Do pockets of pure animals exist (3) Examination of biochemical divergence between the pure and hybrid animals using mtDNA and isozymes - Are there markers for hybrids ? Thus an isozyme sampling regieme will be required - blood sera and livers will be available - Micropopulations may be examined if there can be enough samples collected, to examine any correlation between biochemical and morphological characteristics, and the effect of known bottlenecks. If sufficient samples cannot be acquired from a small area, the area will just be increased ! So how many animals make a sample ??? John P.S.: this is a rather simplified view of a very complex problem which has serious implications with regards species conservation here in Ireland. If anyone is interested I can send you (or the list) more information with regards the history of the problem, problems in Cervid taxonomy, and the research done so far to elucidate this problem with speciation. A number of abstracts and reports are available ..... just give me a note !