22 



59. — . 197^^. On the origin of parthenogenesis in vertebrates: the 

 cytogenetic factors. AMERICAN NATURALIST 108(963): 625-6^^8. 



The evidence for and against the hybridization theory (hybridi- 

 zation— > diploid unisexuality— > polyploidy) and the spontaneous origin 

 theory (ability to produce unreduced ova is genetically acquired— >di- 

 ploid unisexuality— > polyploidy) is reviewed. Cuellar is biased in 

 favor of the latter, which states that hybridization does not result 

 directly in parthenogenesis but only favors it through heterosis. The 

 evidence presented actually supports both theories; that is to say, 

 neither theory can be ruled out depending on the individual circum- 

 stance. The evidence supports the hybridization theory in Cnemidophor - 

 us, in the opinion of this reviewer. 



60. — . 1976. Intraclonal histocompatibility in a parthenogenetic 

 lizard: evidence of genetic homogeneity. SCIENCE 193(^2^*8): 150-153. 



A total of 175 skin grafts were transplanted among 20 individuals 

 belonging to two separate populations of Cnemidophorus uniparens . Only 

 intraclonal (= locality) transplants were done. 99.8% were permanently 

 accepted, which indicates that all individuals of each population may be 

 genetically identical. These results further suggest that large popula- 

 tions or the entire species may consist of one clone derived from a sin- 

 gle individual. All allografts done with _C. tigris (a sexual species), 

 using the same procedures, are eventually rejected. Histocompatibility 

 genes are discussed and it is suggested that the technique described 

 here could be used to determine actual mutation rates in parthenogenetic 

 clones, provided that mutant individuals exist and can be detected. 



61. — . 1977a. Genetic homogeneity and speciation in the partheno- 

 genetic lizards Cnemidophorus velox and Cnemidophorus neomexicanus ; 

 evidence from intraspecific histocompatibility. EVOLUTION 31(1): 2^^-31. 



This study was conducted to determine more precisely the degree of 

 variation in histogenes within and between populations to understand as 

 nearly as possible the extent of genetic variation throughout the range 

 of a parthenogenetic species, and thus perhaps shed further light on the 

 probable origins of parthenogenesis. _C. velox , with a wide geographic 

 range, and _C. neomexicanus, with a restricted geographic range, were 

 used. Lizards of the latter species, from ^ separate localities encom- 

 passing 160 miles of the species' range, underwent intra- and interio- 

 cality skin transplants. 99+% of the grafts were retained, implying 

 that the lizards over this geographic area are genetically identical. 

 Lizards of the former species from 2 localities in Utah, 1 in Colorado, 

 and 2 in New Mexico were subjected to the same procedure. All intra- 

 locality grafts were accepted, as well as interlocality grafts between 

 the 2 clones in Utah and the 2 in New Mexico. All interlocality grafts 



