Speciation And Evolution Of Cichlids

“In the 1950s the Nile Perch was introduced into Lake Victoria to boost the fishing community.” (National Geographic Society, 2015) But when introducing this fish into the lake it came with positive and negative effects. On the positive side, it created an economic boom. For negative effects, it caused the near extinction of a native fish known as the Cichlid (National Geographic Society, 2015). As far as the Cichlids becoming nearly extinct when this unusual fish entered their native home they were not prepared to defend themselves from this fish they had never encountered before (National Geographic Society, 2015). Soon after the cichlids were becoming extinct they were being overly fished and the Nile perch was running out of food resources and the Nile Perch population would soon decline ( National Geographic Society, 2015).

As seen with Anolis, single species of organisms have the ability to undergo adaptive radiation and become new species by filling niches in a given environment. This is prevalent not only in Anolis, but other model organisms as well, such as finches, sticklebacks, and cichlids. All of these organisms have gone through the similar mechanisms and processes to evolve into different species. Alike to Anolis, they have gone through reproductive isolation, adaptation, and convergent evolution. Due to a poor fossil record of Anolis, the other model organisms may give better outlook on how they have diverged overtime. Further investigations on all of these organisms and their evolutionary mechanisms would not only give better a better idea of ecological speciation, but more comprehension on the origin of all

Over the last several years, evolution has been playing an increasingly important role in determining how various species are evolving. This is because ecology will have an impact on how quickly a particular organism is able to adapt (with: the unique challenges for a particular environment). To determine the effect that this is having requires carefully examining different species over the course of many years. This will be accomplished by comparing these changes on Darwin and Wallace Islands. Once this occurs, is when specific insights will be provided that are highlighting the underlying challenges affecting the development of organisms. This is the point that these transformations will be evident among the various life forms. (Fasolo, 2011, pp. 53 68)

Evolution is one of the most important factors when looking at history. A crucial moment in evolutionary process is speciation. Fortunately, we have the fossil record of a transitional species called tiktaalik. Tiktaalik was the transitional species of sea creature that would evolve into a land creature. It was found on Ellesmere Island in the Canadian arctic and is believed to be around 383 million years old (Class Lecture).

Phylogeography is a field of study that implements biogeography and genetics to understand the geographic distribution of a species. It is concerned with historical principles and processes that influence evolution and speciation. The tiger is an evolutionary wonder; it is a prime example of the responsiveness that some species have to changing climatic conditions. The tiger once had the largest geographic distribution of all cat species; subspecies adaptations allowed them to live in a large range of habitats throughout the Asian continent making it a perfect candidate for the study of phylogeography. This review will examine the evolutionary history of the tiger and will explain how the species was affected by climatic fluctuations and biogeographic processes during the Plestocene epoch.

The Chrysalids by John Wyndham is a science fiction novel that sets place in the future long after a nuclear holocaust has devastated large areas of the world. The stories focal point is on the people in a group of highly intellectual people that are compelled to leave and go to the story calls “The Fringes”. This is a place where people who do not fit God’s true image go. What this means is, is if you have any type of deviation, you will be considered abnormal. The novel is written in first person and told by the character David Strorm. David is one of the advanced children. The story takes the reader through David’s life and the things that happen in his life throughout the entire course of the novel. The Chrysalids expresses the precise

1. Neil Shubin, author of Your Inner Fish, and his colleagues travel to Ellesmere Island to look for and study the shift from fish living in water to creatures living on land (4). Fossils from 360 million years ago include amphibians and reptiles. Fossils 385 million years old, only fish are found. Because of this, Shubin and his colleagues look at the time in the middle of this, 375 million years ago (10). In 2004, they give it another try, after failed previous tries (21). What gradually emerges from the rocks they searched for in the bottom of the quarry is an “intermediate” right between fish and land animals, Tiktaalik, “large freshwater fish” (22-25).

The Out-Africa-Theory that has been heavily sided with is the hypothesis that remains the most likely to have happened. Not only because that is the theory that has the most scientific evidence but also because that is were the remains of the oldest primate fossil on all seven continents have been found. Even though the recent evidence in Asia is very convincing, there is too much noteworthy evidence found in Africa that an not be ignored. Moreover, such a new theory is lacking a substantial amount of evidence and investigation in order for it to become convincing theory. This leads the scientific world to side with the fact that we have deeper-rooted ancestry in Africa.

In the marine lab, there is a Texas Cichlid named Kevin or Texas Toast. It is also known as “Herichthys cyanoguttatu” (Sharpe, William). It was brought to Europe in 1912 and it’s the only cichlid that is found in the United States (Sharpe, William). The Texas cichlid is now in the northern part of Texas to Florida mostly due to people getting rid of the fish because they don’t want to take care of it anymore (Sharpe, William). It is a favorite fish to catch (Sharpe, William). The Texas cichlid is normally in the lower portion of the Rio Grande Drainage (Berg, William).

Although only about half of the Lucilia species listed as valid by Aubertin (1933) were included, these results strongly suggest that L. sericata and L. cuprina are indeed sister species. All of the Bayesian inference analyses (Figs 1–3) indicate that L. sericata and L. cuprina are sister taxa with strong support from the nuclear gene (28S & Per) and total data (28S, Per & COI) trees and weaker support from the COI gene alone. Lucilia cuprina is paraphyletic (Fig. 2) with respect to L. sericata in the mitochondrial gene (COI) tree, as has been shown previously (using the same sequences but weaker auxiliary taxon sampling) to be the result of introgressive hybridisation between these two species (Williams & Villet, 2013). In another study, the nuclear gene elongation factor-1 alpha (EF-1α) did not recover L. sericata and L. cuprina as sister-species (McDonagh & Stevens, 2011), but the clade containing L. sericata was poorly resolved and thus the conclusion was not well supported. In the same study, the 28S and COI gene trees both recovered L. sericata and L. cuprina as sister species with strong support (McDonagh & Stevens, 2011).

Additionally, I. longirostris was genetically different among and across rivers. This first insights about the population genetic structure of I. longirostris is crucial for monitoring the genetic diversity, management and conservation of its populations and complementing the genetic studies in Prochilodontidae.

In the case of ring species, natural selection and sexual selection each play a role in the divergence of ring species. Selective pressures allowed one phenotype to survive better than others in a certain area; sexual selection could cause divergence because organisms choose mates based on phenotypes. In the case of salamanders, natural selection affected divergence because organisms with certain coloration survived better in coastal or inland environments. In warblers, sexual selection and natural selection seem to play a part in the divergence of the ring species, as forest density and migration distance is variable and affects survival of the species. Molecular and morphological evidence can be used to support multiple species by showing

The Out of Africa Theory is a widely renown theory describing the origin of the human race and their early dispersal throughout the world. According to this theory, humans have a monogensis, or a single and common origin; Africa. The concept was first introduced in 1871 by Charles Darwin but was deliberated for years until further studies of mitochondrial DNA and evidence ”based on physical anthropology of archaic specimens” was added.

The type of food cichlids require is another way this breed differs from each other. It is thought to be one of the reasons they are as widespread and successful as a species. Some eat algae and vegetation, while others eat other fish and snails. Also, some are highly aggressive and territorial, while others are shy and timid. The aggressive, fish eating species have often proved troublesome for uninformed aquarium

Evolution occurs when an animal species develops new bodily structures and functions in order to adapt to their new environment. These developments are seen as positive adaptations that enhances survival. However, some animal species have lost these new developments. Based on the geographic location and climate, some evolutionary developments that are no longer needed are lost due to the fact that the new bodily structure itself does not enhance the chance of survival in a particular environment (Kirchman 2009; Vieites, et al. 2009). In most cases these lost developments are passed down through future generations and are never redeveloped. However, more information is needed to decide whether or not the loss of these evolutionary developments was due to natural selection or by random mutation over years (Wilkens and Strecker 2003). In this paper, I will examine three studies from a diversity of taxa, which illustrate the history of flightless birds, how climate has influenced the evolution of salamanders and how life lived in darkness has influenced the blindness in cave fish. Together these studies depict how these evolutionary abilities are lost and their affects on the animal species.