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Due to artificial selection, dogs have high levels of phenotypic diversity, yet, there appears to be low genetic diversity within individual breeds. Through their domestication from wolves, dogs have gone through a series of population bottlenecks, which has resulted in a reduction in genetic diversity, with a large amount of

Due to artificial selection, dogs have high levels of phenotypic diversity, yet, there appears to be low genetic diversity within individual breeds. Through their domestication from wolves, dogs have gone through a series of population bottlenecks, which has resulted in a reduction in genetic diversity, with a large amount of linkage disequilibrium and the persistence of deleterious mutations. This has led to an increased susceptibility to a multitude of diseases, including cancer. To study the effects of artificial selection and life history characteristics on the risk of cancer mortality, we collected cancer mortality data from four studies as well as the percent of heterozygosity, body size, lifespan and breed group for 201 dog breeds. We also collected specific types of cancer breeds were susceptible to and compared the dog cancer mortality patterns to the patterns observed in other mammals. We found a relationship between cancer mortality rate and heterozygosity, body size, lifespan as well as breed group. Higher levels of heterozygosity were also associated with longer lifespan. These results indicate larger breeds, such as Irish Water Spaniels, Flat-coated Retrievers and Bernese Mountain Dogs, are more susceptible to cancer, with lower heterozygosity and lifespan. These breeds are also more susceptible to sarcomas, as opposed to carcinomas in smaller breeds, such as Miniature Pinschers, Chihuahuas, and Pekingese. Other mammals show that larger and long-lived animals have decreased cancer mortality, however, within dog breeds, the opposite relationship is observed. These relationships could be due to the trade-off between cellular maintenance and growing fast and large, with higher expression of growth factors, such as IGF-1. This study further demonstrates the relationships between cancer mortality, heterozygosity, and life history traits and exhibits dogs as an important model organism for understanding the relationship between genetics and health.
ContributorsBalsley, Cassandra Sierra (Author) / Maley, Carlo (Thesis director) / Wynne, Clive (Committee member) / Tollis, Marc (Committee member) / School of Life Sciences (Contributor) / School of Human Evolution and Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
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Description
There are many anecdotal stories of dogs rescuing their owners from dangerous situations, but this rescue behavior has yet to be shown in an experimental setting. Studies have shown that dogs behave differently towards crying humans, but do not seek help for their owners when they are in distress. This

There are many anecdotal stories of dogs rescuing their owners from dangerous situations, but this rescue behavior has yet to be shown in an experimental setting. Studies have shown that dogs behave differently towards crying humans, but do not seek help for their owners when they are in distress. This study sought to determine if a dog could recognize when its owner was in distress and would attempt to rescue the owner. The experiment consisted of three conditions: a distress condition to determine how dogs respond to an owner calling for help, a reading condition to control for proximity-seeking and sound, and a food control to use as a basis for motivation and door-opening ability of the dog. Sixty dogs were tested in all three conditions in a pseudo-random order so that an equal number of dogs completed the conditions in each order. 38% of the dogs opened the apparatus for any condition, while 32% opened for the food and distress conditions and 27% opened for the reading condition, which shows that rescue in general is unlikely. There was no significant difference in the proportion of dogs who opened the apparatus for each condition, indicating that dogs are no more likely to rescue their distressed owners than they are to open the apparatus for other conditions and may not be able to sense that the owner is in distress. The similarities in the success rates also show that the owner can be just as motivating for a dog as food. Overall, the low success rates suggest that dogs are not generally likely to rescue a person who is trapped, even when they are calling for help.
ContributorsPatterson, Jordan Elizabeth (Author) / Wynne, Clive (Thesis director) / McBeath, Michael (Committee member) / W.P. Carey School of Business (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
We compared sociability towards humans of domesticated and tame members of several Canidae: Belyaev's fox (Vulpes vulpes), red fox (Vulpes vulpes), gray wolf (Canis lupus), dingo (Canis l. dingo), New Guinea singing dog (Canis l. dingo), and dog (Canis l. familiaris). We defined sociability as motivation or willingness to engage

We compared sociability towards humans of domesticated and tame members of several Canidae: Belyaev's fox (Vulpes vulpes), red fox (Vulpes vulpes), gray wolf (Canis lupus), dingo (Canis l. dingo), New Guinea singing dog (Canis l. dingo), and dog (Canis l. familiaris). We defined sociability as motivation or willingness to engage with humans. Our operationalized definition of sociability is the latency to approach (LTA) the human experimenter and the amount of time the canid spent within one meter of the human experimenter (PTC). We added an unfamiliar and familiar experimenter condition to deduce whether or not canids discriminated on who they were more social with: an owner or a stranger. To each experimenter condition we added a passive and active phase to discern whether or not canids were more social when called or not. Across all conditions and phases dogs were significantly more social than all other canid types. We concluded genetic differences due to domestication and environmental differences due to socialization accounted for sociability differences seen in dogs compared to the other canid types.
ContributorsBeckstrom-Sternberg, David Tristan (Author) / Wynne, Clive (Thesis director) / McBeath, Michael (Committee member) / School of International Letters and Cultures (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05