Taiwan is a continental island formed via arc-continent collision of Philippine Sea plate and Eurasian plate. The collision caused a major physical barrier, the Central Mountain Range, for animals inhabiting in lowland areas and contributed to divergence between western and eastern regions in interspecific or intraspecific levels (Wang et al. 2007, Jang-Liaw et al. 2008, Huang and Lin 2010, Lin et al. 2012). Aegista subchinensis (Möellendorff, 1884) is one of the most widely distributed Aegista spp. with frequent occurrence in hardwood forests near Central Mountain Range (Hsieh 2003, Lee and Chen 2003, Lee and Wu 2004, Hsieh et al. 2006, Hsieh et al. 2013). The morphological differences observed between western and eastern populations indicated that the diversity of this species complex might be underestimated and requires further investigation (Lee and Chen 2003, Lee and Wu 2004). With evidences of multi-locus genetic marker and morphology, we considered that the Aegista snail from eastern Taiwan, which originally identified as A. subchinensis, was a new species and named it as A. d...
For the original analysis, the corrected pairwise distance will be calculated using the Jukes–Cantor and the Maximum Composite Likelihood Model. The Jukes–Cantor model assumes that the rate of nucleotide substitution or all nucleotides (C, A, T and G) are equal, that nucleotide frequencies are equal, that there is an equal rate of substitution among sites, and does not correct for the lower rate of transversion substitutes in comparison to transitional substitutions (Jukes and Cantor, 1969). The Maximum Composite Likelihood takes into account the phylogenic relationship between sequences, using the sum of the log likelihoods of the bases as the composite likelihood. Both pair wise distances and substitution parameters are estimated using the Maximum Composite Likelihood (Tamura et al. 2004). Both models should yield different maximum sequence divergence and average divergence that can then be compared to the original paper. With sequence divergence data, the temporal origin of the genus can be identified. The two alternate models to the Kimura-2 parameter will be analyzed to discuss which methods yield results closest to the expected time origin of the genus
There was a beautiful island in the middle of the Baffin Bay, near Greenland. Two monkey tribes lived on the island; the island was called the Island Island of Islands. They shared the island peacefully. On the west side of the Island Island of Islands, where King Shrimp ruled, living conditions were deteriorating. Food was becoming scarce and the Shrimpanzees, (half monkey, half shrimp animal, a spell cast long ago by King Shrimp on his followers) were dying sooner than their counterparts living under King Steve’s rule. That is when King Shrimp began to make a plan to take over the entire island, King Steve’s region. King Steve was a fabulous person. He was fair, kind, calm and a regular chimpanzee. On the other hand, King Shrimp was unfair, mean, and wanted the island to himself. He was also a Shrimpanzee, not married, the exact opposite of King Steve. King Steve wanted to share the island peacefully. Before King Shrimp could start planning, he had to see what King Steve was doing. He sent one of his spies to dress up as a chimpanzee, and see life was like on the other side.
Interestingly, Hawaiian cave planthoppers rank among the highest speciation rates among all animal species, which contradicts the prior assumption of the limited evolutionary potential of obligate cavernicoles. Furthermore, the differentiation between the species is random with regard to cave age and geographic distribution. Overall, the Hawaiian cave planthopper system provides an ideal model for testing models of stochastic effects in evolution in a natural system for several reasons. First, the system is simple enough to allow distinction between different factors affecting speciation rates. Also, the system is essentially a series of populations undergoing “natural experiments” of repeated events under similar conditions, which allows for the assessment of relevant factors. The Hawaiian planthoppers seem to directly challenge the Founder-effect concept by Mayr, which hypothesizes a loss of genetic variation that occurs when a new population ...
Mercer, J. M., & Roth, V. L. (2003). The Effects of Cenozoic Global Change on Squirrel Phylogeny. Science, 299(5612), 1568-72. Retrieved from https://search-proquest-com.ezproxy1.apus.edu/docview/213583204?accountid=8289
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.
In his essay, “My Island Life,” Luke Harmon discusses the importance of islands and how they have been used by evolutionary biologists to study evolution and diversification on Earth. Harmon focuses on biogeography and on how different species are distributed across the Earth. Harmon also makes a point to mention how human introduction of invasive species is rapidly causing islands around the Earth to become uniform and less diversified. Harmon’s research on the evolutionary history of lizards found on two separate regions of Islands begins with the influence of Wallace’s line, discovered by Alfred Russel Wallace. This line is described as invisible boundaries that separate Earth into provinces, and these provinces contain distinct species. Wallace noticed that the physical influences and conditions did not change across the line, but the species inhabiting it did. With Wallace’s discoveries in mind, Harmon hypothesizes that by studying the diversification and evolutionary history of two different lizard species, anoles and day geckos, will show how evolution can be predictable.
While in graduate school, Stephen Gould met fellow graduate student Niles Eldredge and they both began to study the many snail fossils. In a New York Times article Stephen Jay Gould, 60, is Dead; Enlivened Evolutionary Theory (2002), it is stated that “the two students could not find the gradual, continuous change in fossil forms that they were taught was the stuff of evolution. Instead they found sudden appearances of new fossil forms followed by long periods in which these organisms chang...
Jamison, I. G. (2007). Has the debate over genetics and extinction of island endemics truly been
to discuss changes in habitat and environmental variability, nature of diet and dietary changes, and nature of and reliance on fallback foods of extinct great apes; and
The Galapagos Islands, located about 600 miles west of continental Ecuador, contain a rich history of settlement and exploration and represent a living example of evolution that is still relevant today. For centuries, this chain of volcanic islands has been used uniquely by various cultures based off distinct needs. What has remained the same however is the fact that island isolation has forced many animal and plant species to adapt differently from one another based off their island’s environmental conditions, creating a living model of microevolution over time. Today, these models tend to be the primary resources used by biology professors when teaching their students evolutionary topics.
In 1996, the Asian Longhorn Beetle made its way into the New York and New Jersey creating the decimation of the forests. The Asian Longhorn Beetle has so far caused the cutting of over 10,000 trees in New Jersey, and quarantine of 109 miles in New York today . The spread of this foreign beetle has created great impacts on the environment. The Asian Longhorn Beetle is an invasive specie, a harmful specie from another locations, mainly other countries, that has ended up in a foreign habitat. As time has progressed, invasive species have continued to come into our environment more frequently creating many unforeseen consequences. The relationship of invasive species within the United States’ environment and ecosystem has been changing ever since the arrival of the Europeans in the 1700s to present day. Due to these encounters with other species whether harmful or neutral, the majority, if not all, of the United States has been affected with the threatening encroachment of native species due to the industrialization of waterways and transportation.
Luikart, G., J.M. Cornuet. 1998. Empirical Evaluation of a Test for Identifying Recently Bottlenecked Populations from Allele Frequency Data. Conservation Biology 12:228-237.
When Hoekstra et al (2004) discovered a lower reflectance rate in the darker, melanic mice, they realized the heterozygous mice had an intermediate phenotype. The homozygous dominant and recessive had higher reflectance rates than the heterozygous organisms. However, habitat selection was unique. Hoekstra et al (2004) frequently found heterozygous mice on light rocks and homozygous, melanic mice on dark rocks, illustrating the selection against the light colored mice residing on the dark lava bed. When looking at migration, Hoekstra et al (2004) discovered there was stronger immigration than emigration to the Pinacate Lava
Modern-day genetic technology has granted mankind with the opportunity to bring back extinct species from the dead. If humans have come to possess the DNA from an extinct animal population, it is possible to create an identical clone of the animal in question, effectively “bringing it back from the dead”. Many ethical dilemmas surround the practice of de-extinction, and rightfully so. Recreating an extinct species could produce groundbreaking scientific breakthroughs, generating exciting opportunities for future genetics-based research. However, there could also be monumental consequences: the newly revived, once-extinct species might destroy the ecological equilibrium of modern Earth
Humans are destructive. Not a lot of us think about how what we do affects the world around us. We almost act like we are the only ones on this planet. We go around polluting and destroying our world with no regard for our actions. The things that live out in the wild are paying the price for it. Every day that passes there is another animal or plant that is placed on an endangered list. This is happening at an alarming rate. Because of man’s desire to expand and conquer their surroundings, there are animals and plants that are on the brink of extinction that will not be around for our kids and future generations to enjoy if something is not done about it now. This problem has been going on for hundreds of years. There are animals and plants that can only been seen in paintings or early photography. It is because of our early ancestors that we have this problem today and we have to do more to prevent more animals and plants from disappearing forever.