Seahorse Hippocampus Introduction
Seahorses are a prime example of species whose atypical biology and unusual global distribution leads to a series of evolutionary questions. Seahorses (genus Hippocampus) are a marine species that have extensively been studied because of their abnormal behaviors in the marine environment compared to other marine creatures. Many of the seahorse species have large ranges, both longitudinally (over a great horizontal distance across the ocean), and latitudinal (great vertical distance within the ocean), regardless of the fact that they are characterized as weak swimmers and lack any large structural fins for efficient swimming (Lourie et al., 1999a). Although they do have these large range environments, seahorses
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The first goal was to accumulate the molecular phylogeny data for seahorses using the cytochrome b gene sequence information (S.P. Casey et al, 2004). In this particular study, the cytochrome b gene was used to investigate whether or not the Hippocampus was indeed pre-Tethyan in origin and to illuminate the relationship between Indo-Pacific and Atlantic seahorse species. Molecular markers like the cytochrome b gene were used to survey dispersal of seahorse species and to temporally define the evolutionary processes since much of the seahorse fossil record is deficient (Lourie et al., …show more content…
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
Hippocampus is a small, curved region, which exists in both hemispheres of the brain and plays a vital role in emotions, learning and acquisition of new information. It also contributes majorly to long term memory, which is permanent information stored in the brain. Although long term memory is the last information that can be forgotten, its impairment has become very common nowadays. The dysfunction is exemplified by many neurological disorders such as amnesia. There are two types of amnesia, anterograde and retrograde. Anterograde amnesia is inability in forming new information, while retrograde refers to the loss of the past memory. As suggested by Cipolotti and Bird (2006), hippocampus’s lesions are responsible for both types of amnesia. According to multiple trace theory, the author suggests that hippocampal region plays a major role in effective retrieving of episodic memory (Cipolotti and Bird, 2006). For example, patients with hippocampal damage show extensively ungraded retrograde amnesia (Cipolotti and Bird, 2006). They have a difficult time in retrieving information from their non-personal episodic events and autobiographical memory. However, this theory conflicts with standard model of consolidation. The difference between these theories suggests that researchers need to do more work to solve this controversy. Besides retrieving information, hippocampus is also important in obtaining new semantic information, as well as familiarity and recollection (Cipolotti and Bird, 2006). For instance, hippocampal amnesic patient V.C shows in ability to acquire new semantic knowledge such as vocabularies and factual concepts (Cipolotti and Bird, 2006). He is also unable to recognize and recall even...
The background of this article gives information that is necessary to understand the experiment. The shape of the pelvic girdle is an appropriate predictor of both phylogeny and movement in terrestrial vertebrates. However, in marine vertebrates, the gravitational forces typically applied to terrestrial pelvic girdles are not there and therefore have little impact on the shape of the girdle. Pelvic girdles of fish are generally not attached to the vertebrae and primarily are used as a place for muscles to attach and supporting of the fins. The authors discuss how in many cases the pelvic girdle could be removed and not result in any complications. However, there are some marine vertebrates that are capable of bottom walking on the ocean floor with their fins. In batoids, the pelvic fins are used for walking, which is when pelvic fins move in an alternating fashion, or punting, when both pelvic fins move at the same time. There is also augmented punting; this is when the vertebrate uses both the pectoral fins and the pelvic fins to generate more thrust, this action decreases the forces on the pelvic fins during a punt. While this locomotion would
Although the Hippocampus spp. are placed into the same class as other organisms more traditionally viewed as fish, their morphology bears distinct differences in comparison to other bony fish. The various species belonging under the genus Hippocampus range in maximum size from 20 mm to 300 mm(Foster 8). Their physical appearance is distinct from other members of its class due to their "horse-like head, monkey-like tail, and kangaroo-like pouch."( Lourie et al 12) Morphologically, seahorses do not have scales like traditional fish, but rather posses bony plates covered by skin. The appearance of bony extrusions and skin ...
Scientists had some idea to the evolutionary process of whales. “It has always been clear that aquatic cetaceans must have evolved from terrestrial mammals and returned to the water, and the forelimbs of recent cetaceans still have the same general pattern as that of land mammals.” (Walking with Whales) It was known fact that land mammals and whales were related. However, the change from ancient whales to modern whales is drastic.
The Dwarf Seahorse’s predators include tunas, dorados, skates and rays, penguins, crabs, and water birds. Young dwarf’s are at the risk of at t...
The seahorse is a small species of vertebrate that is found in the tropical shallows and temperate waters around the world.
The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.
Episodic memory which is memory of what happened, where and when aspects of an event is a popular concept in psychology . It is a well studied phenomena in human psychology. With a growing interest to test the existence of episodic memory in other animals, which is hard to demonstrate as there is always ambiguity due to lack of mutual language in non human subjects. Thus, the researchers came up with a term episodic like memory to represent the phenomena in non human animals. In a study Clayton and colleagues, showed the scrub jay demonstrate episodic like memory. Reserachers stored favourite food of jay worms which decay quickly and peanuts. The caching behaviour of jays showed they remembered the when aspect of food stored along with what and where. After short delay jays searched for their preferred food worms versus peanuts. As the delay increased jays preferred peanuts over worms indicating they had a sense of time thus would avoid worms after delay. In my sight, there can be alternative explanations to this blue jay experiment and similar ones which attempt to demonstrate episodic like memory in n human animals. Firstly, instrumental learning which is that a behaviour is learnt as a result of consequences of it. Positive consequences will lead to the likelihood of the behaviour to be repeated and negative consequences will lead to avoidance of the behaviour in the future.For example, if an animal eats a food and gets sick. It will learn to avoid it in the future. Secondly, stuck in time hypothesis, which is that animals are unable to disconnect current from present and past. Thus the behaviour shown which is taken as a evidence for episodic memory can be just the difference in decaying of information. Another explanation can...
The concept of transitional species is an important and complex notion in evolutionary biology. To begin with, there is no such thing as transitional species since all living things were always evolving in the past, not stopping at one stage or another, and they will continue to evolve in the future. In terms of evolutionary biology, we use the concept of transitional species as a way to dim ambiguity. Much like the use of the Linnean taxonomic system of species, we come up with concepts like transitional species to organize and classify species in order to understand their evolutionary roots and how those species changed through life’s history to become what they are today. “In the same way that the concept of species can be provisionally meaningful to describe organisms at a single point in time, the concept of transitional species can be provisionally meaningful to describe organisms over a length of time, usually quite a long time, such as hundreds of thousands or millions of years” (111). Though it can be difficult to distinguish what can be considered an ancestral species from another, the fossil record can show us how species change through time as they develop ways to adapt to stresses found in their environments. “In the modern sense, organisms or fossils that show intermediate stages between ancestral and that of the current state are referred to as transitional species” (222). The concept of transitional species is, in essence, fairly straight forward. This paper will outline the concept of transitional (or sometimes termed intermediate) species and the latter’s role in evolutionary biology, as well as go in depth about several common transitional species: Tiktaalik, an animal at the cusp between life in the water and ...
Gould, Edwin, George McKay, and David Kirshner. Encyclopedia of Mammals. San Francisco, CA: Fog City, 2003. Print.
Seahorses have proven to be amazing animals with a plethora of characteristics that make them truly one of a kind. Seeing one in the wild is rare and they are becoming harder and harder to find due to increasing demand by humans and destruction of they’re habitats.
When diagnosed with probable Alzheimer's disease the effect of plagues and tangles are now starting to be seen in many ways including, memory loss in which individuals may have trouble learning new information and consistently ask the same question multiple times, along with disorientation which is an indication that the Hippocampus is being affected by plagues and tangles. The Hippocampus is usually one of the first areas affected by the disease (Brayne, 2014).
"Project Seahorse: Advancing Marine Conservation." Essential Facts about Seadragons. N.p., n.d. Web. 20 Apr. 2014. .
Marine organisms continue to amaze scientists with their physiological adaptations that allow them to live and thrive in the largest unexplored habitat known to man. Carl Zimmer argues that “most fish without lungs die” because “lungless fish pump their blood in a simple loop.” Therefore, fish are restrained by a lack of oxygenated blood flow that the heart can receive and will die if they exercise too hard because the heart simply won’t receive enough oxygen to sustain intense exercise. In order to solve this problem many species of teleosts and chondrichthyes possess adaptations that allow them to continue exercising at extremely high speeds without necessarily dying. Tunas, for example, are pelagic thunniform swimmers that have evolved these special adaptations that allow them to maintain high cruising speeds and high metabolic rates. They possess special adaptations in muscle, cardiovascular, and respiratory physiology that set them apart from many other species of teleosts.
Convergent evolution explains the similarity in body structure of the swordfish and dolphins, where two different organisms that are not closely related, independently evolved similar structures. Subjected to the similar aquatic environment and similar challenges, the swordfish and dolphins developed a similar body structure, a streamlined body (Figure 12; Baltimore, 2002). The streamlined body is the body structure that is broad in the middle and narrow at both ends. The development of the streamlined body is an advantageous structure to living in an aquatic environment. The streamlined body made it more efficient for locomotion, by reducing water resistance, thus increasing the efficiency of swimming for marine animals and for the vertebrates’