Plant Animal Coevolution:
A study of herbivore and grass coevolution
Introduction
Coevolution may be defined as an evolutionary change in a trait of the individuals in one population in response to a trait of the individuals of a second population, followed by an evolutionary response by the second population to the change in the first (Janzel, 1980). Plant animal coevolution is a very broad topic with many different areas and examples therefore this essay will be focused on the evidence of coevolution between grasses and herbivores. Key questions explored will be how is coevolution studied,
Deciding whether this is coevolution or linked to other factors
It is important to note that not all forms of interaction, mutualism or symbiosis are synonymous with coevolution. It is easy to believe that all mutualistic relationships are due to coevolution, for example animal seed dispersal, but this may not always be the case as the animal may have entered the plant’s habitat with previous dietary requirements and just began feeding on the fruit of the species that suited it best (Janzel, 1980). So how do we determine when it is in fact coevolution? This is done through careful observation, experimentation and phylogenetic analysis. When observing a potential coevolutionary phenomena it is important to ensure the response between the species is indeed reciprocal and not due to environmental factors such as climate, nutrients or pH. Experimentation is a useful way of checking whether an adaptation is due to an environmental factor, some other influence or the species in question. Researchers will study the same interspecific interaction across a number of different communities and continue experimentation over a long period of time to ob...
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...ch of these rosettes produces a flower stalk. This can increase its seed production by up to 3 times as much as those without multiple stalks (Inouye, 1982). This would suggest a mutualistic relationship between the lepidopteran larvae and the Jurinea mollis. Owen and Wiegert have published several articles hypothesising mutualistim, the point they make is that grass- herbivore relationship is not a straightforward predator-prey relationship as grasses can be eaten without being killed. They challenge the assumption that being eaten is a bad and suggest that grazing in fact prolongs the life of the grass (Owen and Wiegert, 1982). However, there is evidence indicating plant defences against herbivores, mainly the presence of silica which increases abrasiveness of foliage and reduces foliage digestibility, reducing in turn herbivore performance (Massey et al., 2006).
Wise, M. J., Abrahamson, W. G., & Cole, J. A. (2010).The role of nodding stems in the goldenrod–gall–fly interaction: A test of the “ducking” hypothesis. Manuscript submitted for publication, Available from American Journal of Botany. (0900227)Retrieved from http://www.amjbot.org/content/97/3/525.full
Many variations and species of plants can be found all around the world and in different habitats. These variations and characteristics are due to their adaptations to the natural habitat surrounding them. In three of many climatic zones, the arid, tropical and temperate zone, plants that vary greatly from each other are found in these locations. In this experiment, we’ll be observing the connection between the adaptations of the plants to their environment at the Fullerton Arboretum. The arboretum is a space containing numerous plants from different environments. The plants are carefully looked after and organized into their specific habitat. Therefore, we’ll be able to take a look at the plants within multiple
A population of Plantago lanceolata (ribwort plantain) on the path was found to have higher trampling tolerance than populations away from the path; this reflected the sharp differences in the conditions of the plant at these sites. Ribwort Plant had generally a higher tolerance to trampling than any other plants as more were found on the path, but there were less compared with other plants as distance increased from the path. These results suggest that the competition level found on the path was sufficient enough to impose a selection pressure for the evolution of tolerance in a sensitive species, but in some areas the distribution of Ribwort Plantain were the same. This provides that other conditions affect the tolerance of trampling for Ribwort Plantain.
Owen-Wilson suggests that wile megaherbivores are not particularly prone to disturbance by predators or the weather, their populations tend to grow up until the point of nutritional deficiency which curiously leads to other vegetation components being trampled or broken by the trampling of megaherbivores (Owen-Smith 355). Sometimes, such damage can actually lead to the creation of different landscapes that provide a "higher biomass of accessible forage" (Owen-Smith 355). However, not all land lends to this kind of lucky damage and megaherbivores can also severely decrease the biomass of accessible forage. In fact, whether or not the megaherbivore will help or hinder is largely dependent on the water resources in the trampled areas (Owen-Smith 356).
The processes of predation affect virtually every species to some degree or another. Predation can be defined as when members of one species eat (and/or kill) those of another species. The specific type of predation between wolves and large ungulates involves carnivores preying on herbivores. Predation can have many possible effects on the interrelations of populations. To draw any correlations between the effects of these predator-prey interactions requires studies of a long duration, and statistical analysis of large data sets representative of the populations as a whole.
As a result of these factors, the flora has adapted to these conditions in a variety of ways including their shape, leaf type, root system, and color. One of the most prominent adapt...
For a species to survive and flourish within a given environment, it not only needs to replace itself but also all the other species around it exclusively. Hence, if one species completely replaces another species, the result is a single dominant species, a monoculture (source 2). According to Gause’s law, every species in a given environment occupies different niches for survival. Therefore, two separate species competing for similar resources cannot fundamentally coexist (source Gause). This is known as the competitive exclusion principle. When comparing animal niche’s to that of different autotrophic plants, one can rather easily differentiate adequate ecological niches for the animal species merely based on food-requirements (P.J. Grubb). On the contrary, many autotrophic plants contradict the competitive exclusion principle by sharing similar ecological niches such as sunlight, carbon dioxide, water, and alike mineral nutrients (p.j. grubb).
Charles Darwin’s theory of natural selection explains the general laws by which any given species transforms into other varieties and species. Darwin extends the application of his theory to the entire hierarchy of classification and states that all forms of life have descended from one incredibly remote ancestor. The process of natural selection entails the divergence of character of specific varieties and the subsequent classification of once-related living forms as distinct entities on one or many levels of classification. The process occurs as a species varies slightly over the course of numerous generations. Through inheritance, natural selection preserves each variation that proves advantageous to that species in its present circumstances of living, which include its interaction with closely related species in the “struggle for existence” (Darwin 62).
In “The Fish” by Elizabeth Bishop, the narrator attempts to understand the relationship between humans and nature and finds herself concluding that they are intertwined due to humans’ underlying need to take away from nature, whether through the act of poetic imagination or through the exploitation and contamination of nature. Bishop’s view of nature changes from one where it is an unknown, mysterious, and fearful presence that is antagonistic, to one that characterizes nature as being resilient when faced against harm and often victimized by people. Mary Oliver’s poem also titled “The Fish” offers a response to Bishop’s idea that people are harming nature, by providing another reason as to why people are harming nature, which is due to how people are unable to view nature as something that exists and goes beyond the purpose of serving human needs and offers a different interpretation of the relationship between man and nature. Oliver believes that nature serves as subsidence for humans, both physically and spiritually. Unlike Bishop who finds peace through understanding her role in nature’s plight and acceptance at the merging between the natural and human worlds, Oliver finds that through the literal act of consuming nature can she obtain a form of empowerment that allows her to become one with nature.
Coercion can be defined as forcing someone to do something they do not want to do. In order to determine if coercion will be successful or not one has to look at four key principles: communication, capability, credibility and compliance or “target will.” While the peace settlements after World War I could have been considered coercive, they probably had very little chance of success based on these four stated principles. France communicated that it wanted unreasonable demands including unlimited reparations for the war. Without Great Britain and the United States, France had little capability in enforcing the settlements. In addition, it had little to no past reputation of being able to support its decision in upholding the settlements. Finally,
Purple loosestrifes reduce biodiversity by degrading natural habitats such as wetlands and replaces native vegetation rapidly. They blocks native plants to grow by forming dense mats with their roots. If native vegetation being replaced with purple loosestrifes, it will impact animals, too. In wetlands, hundreds of species rely on native vegetation for their shelter, food source, and breeding to survive. They will lose their habitat by purple loosestrifes’ invasion since none of them solely depends on purple loosestrifes as their food source or shelter. Since they change many factors of the invaded ecosystem, most of flora and fauna will be affected and it will lead to the reduction of the b...
Coevolutionary divergence among sympatric species, such as elk and mule deer, created the idea of resource partitioning resulting from interspecific competition. Traditionally, resource partitioning was evaluated by species temporal avoidance, spatial separation and dietary differences (Stewart et al. 2010). Six different outputs influence mule deer behavior; density of roads, quality of forage, quantity of forage, quality of cover, quantity of cover and interactions between livestock, elk and mule deer (Edge et al. 1990). Habitat choice by mule deer can be a result of direct and indirect competition with elk and livestock, influencing their distribution and population (Edge et al, 1990, Long et al. 2008). Another form of competition is interference
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Extinction, although not as pleasant a concept as the idea of adapting to ones surroundings, plays just as large a role in natural selection as anything else. As one adaptation of a species proves beneficial, and as that variation begins to propagate, the original, less advantageous variant will die off. It is the unchanged species that are in immediate conflict with the species undergoing the natural adaptation that stand to suffer...