Discovering two unknown fossil hominin species at two different locations is incredibly lucky and exciting. However, what is even more incredible is the information we can extrapolate from our findings. The Praenthropus dimorphicus and the Praeanthropus monomorphicus are the two species that we have unearthed the remains of and can effectively detail a number of their respective characteristics. Based strictly on the knowledge of living primates and deductive reasoning, we are able to reconstruct the socio-ecology of both species in terms of their habitat, ranging behavior and territoriality, diet, group size, and mating systems.
The best technique to figure out the habitats of both species is to take a good glance at what surrounds them. In the first site where we located the Praenthropus dimorphicus, we also found remains of a wildebeest and a zebra. Both wildebeests and zebras are known to live in relatively open habitats. From this, we can piece together that Praenthropus dimorphicus also preferred an open habitat – probably grasslands. In the second site where we located the Praeanthropus monomorphicus, where we were fortunate enough in finding the remains of arboreal monkeys close by. And arboreal essentially means living in trees, or a species that spends a significant portion of its life on trees. We can infer that the habitat of Praeanthropus monomorphicus is one where an abundance of trees are present, such as a forest.
One characteristic that is evident in all primate species is home ranges (Boyd 123). It can be assumed that the home range for Praenthropus dimorphicus is relatively large. My reasoning behind this statement is the fact that body size is directly correlated to size of the home range. The larger the sp...
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... consider for both species. For Praenthropus dimorphicus, intrasexual selection was evident among this species. The males (135 kg) are larger when compared to females (60 kg), meaning that sexual dimorphism existed. Therefore, male-male competition ensued over access to females. For Praeanthropus monomorphicus, intersexual selection was evident among this species. I presume this was the case because this was a smaller group size, so females tended to pick their mates, as males could not afford to fight over their female companions.
In conclusion, we are successfully able to recreate the ecosystem of two unknown species from the few pieces of information provided to us. It is important to understand the importance of extinct fossils as they contribute to our understanding of life in the past and hold vital information to how the world was back then.
Hausler and Schmid suggest that speciation exists within the Hadar Australopithecines – that the specimens represent not just one species (afarensis), but two. To support their view, the scientists use calculations showing the sexual dimorphism (the presence of characteristics that differ between male and female members) among Australopithecines. Again, by studying sexual dimorphic traits, the scientists claim that “Lucy” is possibly male, not fema...
Allen, John S., and Susan C. Anton. "Chapter 13 The Emergence, Dispersal, and Bioarchaeology of H. sapiens." Pearson Custom Anthropology. By Craig Stanford. Boston: Pearson Learning Solutions, 2013. 200+. Print.
Dr. Goodall is a well-known British primatologist who has discovered a substantial amount about primates in her many years of research. She has written numerous books, including one that we will be going into depth about called, “Through a Window.” Her book contains personal experiences, research findings, and even pictures to help the readers visualize her scientific breaking moments from her thirty years with the chimpanzees of Gombe. She states that there is are minor differences, and several similarities between humans and the chimpanzees. We will discuss these differences and similarities through their social behavior, intellectual ability, and emotions. To conclude, examine Goodall’s research to adopt what her findings can tell us about our early ancestors, and whether or not her study coincided to the steps of scientific methodology.
The question of what caused the extinction of megafauna during the Late Pleistocene period is one that archaeologists have struggled to answer for decades, but why should it matter? Discovering with certainty the cause of megafaunal extinction would simultaneously prove or disprove any of the proposed implications of each existing theory regarding this massive extinction.
As archeological discoveries of bone fragments and fossils continue to support the existence of homo-sapiens
Quiatt, D., & Reynolds, V. (1993). Primate behaviour: information, social knowledge, and the evolution of culture. Cambridge [England: Cambridge University Press].
The species A. afarensis is one of the better known australopithecines, with regards to the number of samples attributed to the species. From speculations about their close relatives, the gorilla and chimpanzee, A. afarensis’ probable social structure can be presumed. The species was named by Johanson and Taieb in 1973. This discovery of a skeleton lead to a heated debate over the validity of the species. The species eventually was accepted by most researchers as a new species of australopithecine and a likely candidate for a human ancestor.
Kappeler et al (2003) suggest that life history variables also should be included within the socioecological model due to the inferences and conclusions that can be devised of the behavioural ecology of primates. The framework is under constant remodeling due to the new challenges that arise as the variation being observed does not fit within the model’s predictions (Janson, C., 2000). This is likely due to the role of the environment and its significant impact on studies due to the restriction on study sites and opportunities and the unlikelihood of having been able to study primates with no human influence if possible are under high security. And even the impact of the physical environment has been shown to impact the social organization of primate groups (Fiore, A. D., et al, 1994). There is also further research that suggests the significance of the role of infanticide as a reproductive strategy in many primate species (Van Schaik, C. P. et al., 2000). This action is used by the males of the species to eliminate the offspring that pose risk to the male’s reproductive success by extending the time of female
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,
In order to understand the present lifestyles relating to different approaches and tactics applied by humans in mate choice preferences, there is the need to refer to Darwin (1859, 1871) evolutionary perspectives. Darwin (1871) sexual selection is the driving force for males and females reproductive quest for their genes survival. These driving forces have been classified into two categories as intra-sexual and intersexual mate selection.Intersexual selection is male sexual selection process whereby males compete with other males and the females choose the strongest as their ideal partner. Intra-sexual selection occurs when the male species fight among themselves and the strongest gain access to females for
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Celli, Maura L., Satoshi Hirata, and Masaki Tomonaga. "Socioecological Influences On Tool Use In Captive Chimpanzees." International Journal Of Primatology25.6 (2004): 1267-1281. Academic Search Premier. Web. 16 Apr. 2014.
The increase in brain size may be related to changes in hominine behavior (See figure 3). The third major trend in hominine development is the gradual decrease in the size of the face and teeth. According to the Microsoft Encarta Encyclopedia ’98, the fossil evidence for direct ancestors of modern humans is divided into the category Australopithecus and Homo, and begins about 5 million years ago (See figure 1). Between 7 and 20 million years ago, primitive apelike animals were widely distributed on the African and, later, on the Eurasian continents (See figure 2). Although many fossil bones and teeth have been found, the way of life of these creatures, and their evolutionary relationships to the living apes and humans, remain matters of active discussion among scientists.
Sikes, Roberts. and William L. Gannon. "Guidelines of the American Society of Mammalogists for the Use of Wild Mammals in Research." Journal of Mammalogy 92.1 (Feb. 2011): 235-253. Academic Search Premier. EBSCO. Web. 5 Oct. 2011.
Ruff, S. D. (1999). The Smithsonian Book of North American Mammals. In S. D. Ruff, The Smithsonian Book of North American Mammals. Washington, DC: Smithsonian Institution Press.