67 



The relative amounts of phenotypic variation in populations differing 

 in clonal structure were compared with populations of one parent spe- 

 cies, C. tigris . _C. tesselatus consists of at least 18 diploid and 3 

 triploid clones. The presence at some loci of different heterozygous 

 genotypes involving different electrophoretic morphs found in the par- 

 ental sexual species suggests multiple hybridizations as a major factor 

 in generating clonal diversity. The presence of unique alleles in some 

 clones and histocompatibility between pattern classes indicate that 

 some clones may have diverged from a common ancestral clone. R mor- 

 phometric characters of the two species were subjected to univariate 

 and multivariate analyses. Six of 23 tesselatus populations sampled 

 are multiclonal. Seven clones were discovered at Conchas, San Miguel 

 County, New Mexico; heterozygosity at one locus is probably due to mul- 

 tiple hybridizations. The population at Higbee, Otero County, Colorado 

 consists of both diploid and triploid individuals. Diversity in the 

 remaining ^ multiclonal populations was low with no detectable morpho- 

 logical variation among clones. Variability in size- or growth-related 

 characters adjusted for allometry and covariation with size is similar 

 in both species. Variation in 6 of 9 scale characters differs consis- 

 tently as expected between sexual and parthenogenetic populations. 

 How the sympatric clones of the tesselatus complex coexist is un- 

 known. Specimens from the two most clonally diverse populations repor- 

 ted here were collected on weedy roadsides and around trash piles and 

 abandoned houses; perhaps clonal diversity is the result of nondirec- 

 tional environmental perturbations which have not permitted any one 

 clone to competitively replace the others. However, the morphological 

 discontinuities among clones may very well reflect differences in niche 

 utilization or physiological attributes. It is suggested that environ- 

 mentally-induced variability obscures genetic variability of size char- 

 acteristics measured in the two species. It is also suggested that the 

 genotypes of parthenogenetic and sexual taxa differ in their phenotypic 

 responses to environmental change. Genetic variability for phenotypic 

 plasticity in a sexual ancestor will be "fixed in" to different degrees 

 in different clones; eventually in temporally or spatially changing en- 

 vironments surviving clones may be highly flexible general-purpose ge- 

 notypes. Interactions among genes may be qualitatively different in 

 parthenogenetic and sexual genomes. Epistasis and dominance between 

 the parental genomes of diploid tesselatus are more important than ad- 

 ditive effects in determining mean character values in this study, 

 whereas in sexual species genes are selected primarily for their addi- 

 tive effects. The mutational load carried by clonal lineages is great- 

 er than in individuals of sexual species, although this does not seem 

 to be the case in Cnemidophorus tesselatus . Naturally occurring par- 

 thenogenetic organisms would appear to be useful models for examining 

 relationships among genotype, phenotype, and ecology of populations. 



179. ~. 1979c. Phenotypic consequences of parthenogenesis in Cnemi- 

 dophorus lizards. II. Similarity of _C. tesselatus to its sexual paren- 

 tal species. EVOLUTION 33{^): 1167-1179. 



