The Process of Evolution through the Defensive Mimicry
Since we started the semester studying physical Anthropology, our course has heavily focused on evolution. It gave us a better understanding of how through a series of adaptations species have evolved and natural selection species throughout time have evolved into becoming what they are today. While preparing for this research paper, I came across the concept that some species evolve through a process called mimicry . During my initial research on the topic of mimicry I learned that while there may be many types of mimicry. The most evidence has been gathered about defensive mimicry. Within defensive mimicry there is two different forms. Which are Batesian and Müllerian mimicry. The purpose of this paper is to define mimicry, more specifically defensive mimicry. This paper will also describe both types of defensive mimicry found in nature. By the end of this paper I hope to answer the question of whether one type of defensive mimicry is more beneficial over the other.
For the sake of this research paper, it is important to note what evolution is and how it works. Much of what is known today about evolution is based on Darwin’s Theory of Evolution. Evolution is what scientists refer to when talking about biological differences found in species from one generation to another. Darwin’s theory claims that evolution occurs through adaptations that organisms acquire during their lifetime. If these organisms found that these adaptations were advantageous for their survival, then these adaptations are kept and passed along to their offspring. This is what is called the process of natural selection. Darwin claims that natural selection is the nucleus of evolutionary theory. Without natural selection, evolution would not occur.
In terms of mimicry natural selection plays an important role for this to be possible. Mimicry is used to describe the event in which one species evolves to look like a totally unrelated species. Mimics through a series of adaptations, starts to resemble another species because they take notice of that particular species higher chances of survival. Through the physical adaptations that the mimicking species acquire in their lifetime, they are able to confuse their predators. By confusing their predators they are increasing their chances of survival (PFENNIG, 2012). Thus, through mimicry the mimicking species is able to increase its chances of survival and reproduction. This is where natural selection plays its part. The physical adaptations that the mimicking species adopt are kept and passed along to their offspring through the process of natural selection. This leads the mimicking species to evolve, therefore, increasing its opportunities of survival and reproduction.
While it seems that mimicry is a relatively new topic of research in the field of evolutionary science, the first recorded observation of mimicry in nature dates back to 1862. The first person to record what is now knowns as mimicry, was an English explorer and naturalist by the name of Henry W. Bates. Bates made found that there was some similarities between two totally unrelated species. He suggested that this may happen as a response to predators. The similarities, he noted, come about as an “anti-predator adaptation”(PFENNIG, 2012). Bates concluded, that through mimicry one of the species evolves to look like the other, to avoid being preyed upon (PFENNIG, 2012). As can be expected, research done on mimicry since it was first introduced to evolutionary science by Bates in 1862 has vastly progressed. However, even though it has been found that there exists many forms of mimicry, the most relevant and familiar form to evolutionary science is known as defensive mimicry. This refers to one species finding reprieve from predation through mimicry. More specifically, the mimicking species reduces its of being eaten by their predator because they closely resemble another species that was already protected from predation. It has been found that the two most common form of defensive mimicry are what knowns as Batesian and Mülerian mimicry.
Batesian mimicry describes the event in which an edible species evolves into looking like an inedible species to avoid predation (Gamberale-Stille, 2012). An example of Batesian mimicry would be an edible species imitating the color of an inedible species emits as a way of warnings signal to predators. Species who are identified as Batesian mimickers are found to look similar to the model species, this gaining protection predation (Gamberale-Stille, 2012). However, researchers of this topic are in debate of whether Batesian mimicry occurs through a gradual process or a saltational one (Gamberale-Stille, 2012). Meaning some researchers believe that edible species evolve gradually rather than “feature saltational” (Gamberale-Stille, 2012). A research conducted by The Society for the Study of Evolution sheds light on this debate. This research suggests that predators with their “categorization of complex stimuli” (Gamberale-Stille, 2012) are able to distinguish edible and inedible species as their prey. Because the predator is able to able to group what is edible and is not edible by relying on the appearance of of potential prey, this allows for the edible species to be susceptible to mutation. The mutation will begin the process of Batesian mimicry (Gamberale-Stille, 2012). However, in this research it was also found that in order for the process of Batesian mimicry evolution to be saltational, the edible species undergo mutation on one single trait (Gamberale-Stille, 2012). If the edible species has more than one trait it needs to change on its appearance then the process is more gradual. It is gradual because slowly after various series of genetic mutations the edible species will resemble the inedible species (Gamberale-Stille, 2012). Therefore, through a gradual process of Batesian mimicry evolution, the edible species will be able to confuse the predator into thinking it is part of the inedible group, gaining protection through mimicry.
The second type of defensive mimicry is known as Mürelian mimicry. This type of defensive mimicry refers to species; more specifically toxic species, coincide in sharing a trait that acts as a warning sign for predators. By sharing the same warning trait these toxic species are sharing the task of informing predators about their toxicity (PFENNIG, 2012). Research conducted by the Department of Biology in Carleton University suggests that Mürelian mimicry is far more favorable for multispecies communities. Through their research they are able to demonstrate that because predators have learned that rather than trying to determine whether the potential prey is suitable individually, they instead learn to avoid organisms that have similar traits (Beatty et al. 2004). Therefore, Mürelian mimicry evolution is much more favorable for multispecies communities. Not only do these share the role of educating predators on their toxicity, they also share the benefits that come from this form of defensive mimicry.
After conducting research on the topic of evolution through mimicry, it can be concluded that no one defensive mimicry is superior over the other. Both are beneficial forms in which species through natural selection are able to evolve. This evolution through mimicry increases that particular species’ chances of survival and reproduction. Now that the initial questions have been answered, new questions arise. One of them being, species that go through the process of Batesian mimicry evolution after successfully avoiding being preyed upon, what would happen if the predator would also through a series of adaptations of its owns would suddenly be able to digest what they once found to be inedible species? I don't believe that we will ever know everything there is to know about defensive mimicry. Mimicry is considered to be a process in by which species evolve. Thus, because species are always changing from generation to the other until that species ceases to exist. Because species are always evolving the study of defensive mimicry is unlikely to end.
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