The results propose that the balance between natural selection for inconspicuousness and sexual selection for conspicuousness may vary among the lizard populations. At SL, the habitat consists primarily of gray rocks, so the SL collared lizard population has a small chance to hide. Because of this, the male SL lizards are a dull greenish-brown color that is similar to the females and rocks. At GM, the background is more complicated, so the male lizards are more conspicuous compared to the rocks and females (Macedonia et al. 2004). More than double the number of models was preyed upon at SL than at GM, which shows that natural selection restricts sexual selection for colorful males more efficiently at SL than GM. This reveals why the males at SL are duller than those collared lizards at GM. This seems to be different for the WM population.
These male WM populations are more conspicuous than the GM and SL males; however, WM has the greatest predation pressure among the three sites. The investigators suggested that the WM males may look conspicuous outside of its environment, but may actually be cryptic in its complex environment (Baird et al. 1997; McCoy et al. 1997). When this idea was tested, mixed support for it was found. They found that some areas of the site caused the WM lizards to be conspicuous (flowers, lichens, and vegetation) and other areas caused the lizards to be more inconspicuous (rocks and other vegetation) (Macedonia et al. 2004).
Another reason why male WM lizards may be more conspicuous even though the population experiences great predation pressure is the tall grass area in WM. These tall grasses offer great concealment from visually hunting snakes, like the coachwhip. Because the WM collared lizards may se...
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...J. M., Husak, J. F., Brandt, Y. M., Lappin, A. K. & Baird, T. A. 2004: Sexual dichromatism and color conspicuousness in three populations of collared lizards (Crotaphytus collaris) from Oklahoma, USA. J. Herpetol. 38, 343—357.
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Alfred Kinsey was an American Professor of biology and zoology at Indiana University. During his career he decided to shift his focus from studying gull wasps to that of human subjects. He embarked on a study of human sexual behavior by doing a series of interviews consisting of 18,000 people. The first installment of nine books was “Sexual Behavior in the Human Male.” This 30 year project was anything but non-controversial especially with in the realm of the FBI and the United States government. As any breakthrough research goes through, there were positive and negative critiques of his study.
Intro: Charles Darwin’s natural selection comes to mind when viewing the aggressive behaviors in crickets. This interaction comes into play specifically when competition for resources, such as foods and females, are scarce. Thus, only the organism most fit in the environment would be allowed to survive and pass on its genes. Pioneers of animal behavior, pave the way to understanding the why animals act the way they act (von Frisch, 1967; Lorenz, 1952; and Tinbergen 1951). With further integration between different biological organizations, we see the rise of new possible research, especially in crickets (Wong & Hoffman, 2010). The house crickets, Acheta domesticus, would normally display little to no aggression between males because of their natural behavior to live in groups. But when isolated for a length of time, ag...
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The reason I am writing this paper is to share the information I attained about human sexuality by learning about sexuality in a college setting and by exploring my sexuality through personal experiences. I do not consider myself to have experienced much exposure to sexual behavior but I do have a cultural bias to what I consider a heavy amount of exposure because the North American culture is considered more promiscuous and sexually active than other cultures.
Display, communication, and the act of mating are estimated behaviors involved in the mating process of dinosaurs. The sexual behaviors of modern vertebrae are often used as a starting point to estimate that of dinosaurs. For instance, most modern vertebrae go through a sexual selection process as they choose their mate based on preferred traits. This is demonstrated with the modern day peacock. The visual stimulus the male provides with its tail feathers aids in the opposite gender’s sexual selection process. According to Martin, in this respect, the ceratopsians have the most obvious sexual displays in the form of ornate and broad head shields with horns, knobs, and bosses. Though these body parts could definitely prove useful to fend off potential predators, it is more likely that they were used for: visual recognition within their species; pote...
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...le promiscuity." Nature Genetics 36.12 (2004): 1326-1329. Academic Search Complete. EBSCO. Web. 24 July 2011.
Social groups of primates closely relate to sexual dimorphism, because how each of their communities interact with one another plays a large role in sexual selection. Sexual selection, as Darwin stated, is a key factor and cause in the morphological dimorphism between sexes of a species. Additionally, sexual selection comes from male competition, which directly correlates to primate’s social structures. For example, genus gorilla is a part of a polygynous mating system, which consists of one male and multiple female. This creates an environment where males must compete with one another to reproduce and create offspring. Due to this competition, males must prove to be strong and attract themselves to females to ensure reproductive success. These strong male traits are favored in sexual selection, because the females are highly particular about the male they mate with, so there become specific male traits that are most desirable. Therefore, in polygynous groups, sexual dimorphism is the greatest (Frayer, Wolpoff, 1985). In comparison, a monogamous primate such as genus hylobate or gibbons has a social structure that consists of a more nuclear based family. There is a lot less male competition because males do not mate with multiple females. Therefore, primates are less dimorphic in monogamous social structures (Frayer, Wolpoff,
Eagly and Wood. (1999). The Origins of Sex Differences in Human Behavior. American Psychologist, 51(6), 408-432.
United States. Howden, Lindsay M. and Julie A. Meyer. Age and Sex Composition:2010. Washington: GPO, 2011. PDF file.
Reptiles, one the most widely spread animal group throughout the world. They can live almost everywhere because they adapt so well. Reptiles also come in a lot of shapes, sizes and colors. So let's explore the wonder of these scaly creatures.
The Texas horned lizard can be distinguished by a large flattened body, two large spines on their heads, two rows of fringed scales on their sides, keeled scales on their backs, abdomen, and sides, a white stripe down their back, and brown lines near their eyes (Pianka & Hodges 1995). It inhabits arid environments and preys on small insects, but primarily ants (Oklahoma 1996). The Texas horned lizard is most anatomically similar to the Australian thorny devil, (Moloch horridus), which is most likely due to convergent evolution (Pianka and Parker 1975). Both species of lizards have different phylogenies and lineages, but appear to share common morphological and ecological adaptations due to similar habitats and ...
Glazer, Sarah. "Sexually Transmitted Diseases." CQ Researcher 3 Dec. 2004: 997-1020. Web. 3 April 2014.
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Prause, Nicole, and Cynthia A. Graham. "Asexuality: Classification and Characterization ." Archive of Sex Behavior . 36. (2007): 341. Print.