The Fence Lizard (Sceloporus undulatus complex) is a wide ranging North American species complex occurring from the eastern seaboard westward through the great plains and central Rocky Mountains and into the American Southwest. A recent phylogeny suggests four species lineages occur within S. undulatus. Traits within an interbreeding species that are influenced by sexual selection are under different selection pressures and may evolve independently from the selective forces of habitat. Sceloporus lizards have several characters that are influenced by sexual selection. I investigated sexual size dimorphism and allometric relationships of body size (snout vent length), torso length, rear leg length and three measurements of head size in 12 populations from the four species in the S. undulatus complex (N=352) specifically looking for variation among the 4 species. Additionally I investigated the size of signal patches between males and females in three species (N=339 specimens of S. consobrinus, S. cowlesi, S. tristichus) of the S. undulatus complex. Sexual confusion, was recently described in a population of the Sceloporus undulatus complex occurring in White Sands, New Mexico and the behavior is correlated with variation in badge size between male and female lizards. To make inferences about sexual confusion at the species level I investigated the presence and absence of signal patches in female lizards, and compare the sizes of signal patches between males and females. My analyses suggest that torso length and head size are significant sources of sexual size dimorphism but the findings differ from earlier published investigations of sexually dimorphic characters in the species complex. I also find support for the S. undulatus complex being generally a female larger species complex. However two of the 12 populations I investigated displayed male biased sexual size dimorphism. Analysis of signal patches across three species of the S. undulatus complex suggests that sexual dimorphism in signal patch size for S. cowlesi and S. tristichus may not prevent sexual confusion. While the near total absence of signal patches in female S. consobrinus is evidence that sexual confusion is not possible with regards to signal patches.

Sexual conflict is broadly defined as a conflict between the evolutionary interests of the two sexes. Depending on the genetic architecture of the traits involved, it can occur at the level of male-female interactions or take the form of selection acting to change the mean of a shared trait against the sign of its genetic correlation. The aim of my thesis was to use genome-wide expression profiles in the model organism Drosophila melanogaster to provide novel insights in the study of sexual conflict. First, we studied the female post-mating response to partition transcriptional changes associated with reproduction from male-induced effects, which are known to be harmful to females. We found substantial changes in expression of metabolic pathways associated with the activation of reproduction, while male-specific effects were dominated by the onset of an immune response. Changes in female response under different mating strategies was studied using experimental evolution: we found that monogamous females suffered decreased fecundity and their gene expression profiles suggested an overall weaker response to mating. To identify sexually antagonistic genes, we used hemiclonal lines and associated their sex-specific fitness with genome-wide transcript abundance. We confirmed the presence of a negative covariance for fitness and identified a group of candidate genes experiencing sexually antagonistic selection. We then focused on mitochondria, which can enable the accumulation of deleterious mutations with sex-specific effects due to their maternal inheritance, and found few effects on nuclear gene expression in females but major effects in males, predominantly in male-specific tissues. Finally, we used published data to compare intraspecific and interspecific genetic variation for a set of transcripts, to test whether speciation occurs along lines of maximum genetic variance. In conclusion, gene expression techniques can generate useful results in the study of sexual conflict, particularly in association with phenotypic data or when integrated with published datasets.

Male song and other acoustic signals are often sexually selected traits that are common in many taxa, such as birds, anurans and insects. Song often serves a dual function in female attraction and male-male competition and song characteristics such as duration, rate, repertoire size and amplitude are important for both functions and to be correlated with male reproductive success. Male humpback whales are well known for singing a complex and highly stereotyped song during the breeding season and while the song appears important in the social interactions of humpback whales during the breeding season, the function of song is still unclear. Current debate surrounds whether song is primarily directed towards females as an elaborate acoustic display or towards other males to facilitate male social ordering. The aim of this thesis was to investigate the nature of interactions between singers and conspecifics and document the context in which singing occurs. This was achieved by: (1) investigating the movement patterns and interactions between singing and non-singing whales and (2) examining differences in the song structure and source levels of song within a social context. To investigate song function, simultaneous observations of the positions and movements of singing and non-singing whales were obtained in real time during their southward migration off the east coast of Australia in September and October of 2002 - 2004. Data on the interactions of whales were collected by acoustic tracking using a hydrophone array, visual tracking using land-based hilltop observations and observations collected from a small boat. Of a total 114 singers, 48 did not associate with other whales whereas 66 were involved in 63 associations. Singers were significantly more likely to join groups containing a female and calf than any other group type and the only groups with which singers started to sing after joining were unescorted mother-calf pairs. Singers also associated for longer and sang for a significantly greater proportion of time in the presence of a female-calf pair than any other group type. Previous studies demonstrate that associating with females with a calf can be a reproductively successful strategy for males. In contrast, whales that joined singers were usually lone males, these associations were brief and singers typically stopped singing in the presence of other males. These findings provide the highest reported incidence in humpback whales of males singing when escorting females and support an intersexual function of song in humpback whales. A suggested explanation for observations of males joining singers is that these males are prospecting for females rather than engaging in male social ordering and that singing may incur the cost of attracting competing males. To investigate the importance of surface active behaviours in interactions involving singers and whether singers utilize the acoustic cues from these behaviours to locate other groups, the frequency and type of surface active behaviours were quantified in singing and non-singing groups. Compared to singers that were alone and did not interact with other whales, surrounding groups were significantly closer to a singer (on average 2.8 km distance) when singers joined other groups, and singers joined other groups that were surface active in 54 % of cases. While source levels of different surface active behaviours vary and certain behaviours might be better suited for inter-group communication, it is unlikely that singers rely primarily on acoustic cues from surface active behaviours to locate other groups. Surface activity was not more common in groups just prior to singers joining them, and while not significantly so, surface activity increased when singers affiliated with other groups suggesting an importance in intra-group dynamics. Whereas lone singers were the least surface active, groups containing a calf were found to exhibit a significantly higher rate of surface activity than groups without a calf, for which the calf displayed the majority of behaviours. Considering singers predominantly joined mother-calf pairs, it could be speculated that a high rate of surface activity by a calf might inadvertently attract singers and other surrounding males to these groups and could increase the probability of singers and other males locating mother-calf groups. To further explore a context of singing, the structure and amplitude of songs were investigated over two years for singers in two distinct social contexts; lone singers and singing escorts. A total of 274 songs from 27 singers in 2003 and 2004 were analysed, with a subset of data used for source level comparisons. Lone singers consistently sang longer songs compared to singing escorts due to a greater repetition of phrases most noticeably within one theme (theme C), the theme in which all singers sang the most common song unit (the moan) at higher amplitude compared to the other three themes in which it occurred. These findings suggest that lone singers might increase the repetition of phrases sung at higher amplitude to maximise the broadcast of their song and maximise their probability of detection. In contrast, singing escorts sang shorter songs due to a reduced repetition of phrases in most themes, particularly the theme containing the loudest song units (theme C). Consequently, singing escorts sang the song more quickly, resulting in a higher song rate compared to lone singers. Comparisons of the average broadband source levels of nine song units in the 2004 song showed significant variation among the nine different units and among the 22 individual singers for each song unit. Source levels of one of the nine song units also varied significantly between lone singers and singing escorts. Singing escorts produced higher source levels than lone singers for the ‘cry’ which showed a difference of 4 dB higher than lone singers. Lone singers typically produced higher source levels for the ‘moans’, which were low frequency sounds that propagate well, although this was not significant. We suggest that amplitude of the song might be important in female assessment of singers and the particular song units that singing escorts sing more loudly are the basis for this assessment. These findings further support an inter-sexual function of song in humpback whales. This study has described in detail the contexts in which males are observed to sing and has been able to provide new interpretations on the social interactions of singers. The results within this thesis provide the highest reported occurrence in humpback whales of males singing in the presence of females and strongly suggest that song has an inter-sexual function. Further work is needed that investigates song structure within a social context and the potential for song functioning as a long distance advertisement display and/ or courtship display.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.

Thesis (M.S.) -- University of Montana, 2008. / Title from author supplied metadata. Description based on contents viewed on July 6, 2009. Includes bibliographical references.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Includes bibliographical references. Also available online.

Thesis (M.A.)--State University of New York at New Paltz, 2007. / Also issued in electronic version. Includes bibliographical references (leaves 64-74). Online version available via the SUNY New Paltz Sojourner Truth Library : http://hdl.handle.net/1951/42568

abstract: Conditions during development can shape the expression of traits at adulthood, a phenomenon called developmental plasticity. In this context, factors such as nutrition or health state during development can affect current and subsequent physiology, body size, brain structure, ornamentation, and behavior. However, many of the links between developmental and adult phenotype are poorly understood. I performed a series of experiments using a common molecular currency - carotenoid pigments - to track somatic and reproductive investments through development and into adulthood. Carotenoids are red, orange, or yellow pigments that: (a) animals must acquire from their diets, (b) can be physiologically beneficial, acting as antioxidants or immunostimulants, and (c) color the sexually attractive features (e.g., feathers, scales) of many animals. I studied how carotenoid nutrition and immune challenges during ontogeny impacted ornamental coloration and immune function of adult male mallard ducks (Anas platyrhynchos). Male mallards use carotenoids to pigment their yellow beak, and males with more beaks that are more yellow are preferred as mates, have increased immune function, and have higher quality sperm. In my dissertation work, I established a natural context for the role that carotenoids and body condition play in the formation of the adult phenotype and examined how early-life experiences, including immune challenges and dietary access to carotenoids, affect adult immune function and ornamental coloration. Evidence from mallard ducklings in the field showed that variation in circulating carotenoid levels at hatch are likely driven by maternal allocation of carotenoids, but that carotenoid physiology shifts during the subsequent few weeks to reflect individual foraging habits. In the lab, adult beak color expression and immune function were more tightly correlated with body condition during growth than body condition during subsequent stages of development or adulthood. Immune challenges during development affected adult immune function and interacted with carotenoid physiology during adulthood, but did not affect adult beak coloration. Dietary access to carotenoids during development, but not adulthood, also affected adult immune function. Taken together, these results highlight the importance of the developmental stage in shaping certain survival-related traits (i.e., immune function), and lead to further questions regarding the development of ornamental traits. / Dissertation/Thesis / Ph.D. Biology 2012

abstract: Differences between males and females can evolve through a variety of mechanisms, including sexual and ecological selection. Because coloration is evolutionarily labile, sexually dichromatic species are good models for understanding the evolution of sex differences. While many jumping spiders exhibit diverse and brilliant coloration, they have been notably absent from such studies. In the genus Habronattus, females are drab and cryptic while males are brilliantly colored, displaying some of these colors to females during elaborate courtship dances. Here I test multiple hypotheses for the control and function of male color. In the field, I found that Habronattus males indiscriminately court any female they encounter (including other species), so I first examined the role that colors play in species recognition. I manipulated male colors in H. pyrrithrix and found that while they are not required for species recognition, the presence of red facial coloration improves courtship success, but only if males are courting in the sun. Because light environment affects transmission of color signals, the multi-colored displays of males may facilitate communication in variable and unpredictable environments. Because these colors can be costly to produce and maintain, they also have the potential to signal reliable information about male quality to potential female mates. I found that both red facial and green leg coloration is condition dependent in H. pyrrithrix and thus has the potential to signal quality. Yet, surprisingly, this variation in male color does not appear to be important to females. Males of many Habronattus species also exhibit conspicuous markings on the dorsal surface of their abdomens that are not present in females and are oriented away from females during courtship. In the field, I found that these markings are paired with increased leg-waving behavior in a way that resembles the pattern and behavior of wasps; this may provide protection by exploiting the aversions of predators. My data also suggest that different activity levels between the sexes have placed different selection pressures on their dorsal color patterns. Overall, these findings challenge some of the traditional ways that we think about color signaling and provide novel insights into the evolution of animal coloration. / Dissertation/Thesis / Ph.D. Biology 2012