In truth, large sharks tend to hunt large blubbery prey with a much higher ratio of flesh-to-bone than human beings. That is apparently why many test bites on a human result in no further attack.
In the last decade, a tourist industry has evolved in parts of the world with access to coral reefs and natural shark populations. Hand-feeding excursions allow divers, lead by more experienced professionals to encounter sharks in the wild without a high likelihood of attack. Typically, divers descend to the ocean floor where they assemble into a tight group that de-emphasizes their appearance as meal-sized organisms and merges them (from the sharks' point-of-view into a single larger organism, too large to eat. But other procedures involve much smaller groups of two or three divers to hand feed sharks, relying only on the fact that most sharks tend not to perceive humans as potential prey, unless we exhibit specific characteristics or linger at the surface in their habitat (Perrine, 1995).
On one hand, these industries illustrate how out of proportion our fears of shark attack are in comparison to the reality. On the other hand, these excursions probably increase the incidence of attacks on swimmers and surfers. While sharks do not actively hunt humans as prey, they are very susceptible to learned associations. Shark attacks have been documented to increase in areas where hand-feeding tours operate, simply because sharks in the area learn to associate the sound of boats and human activity with feeding. Once drawn to human swimmers, they may very well initiate test bites on anything in their vicinity, especially, when their expected handouts are not forthcoming (Ritter, 2000).
For the same reason, spot divers are disproportionately more likely to be attacked by sharks, because the spearing of fish triggers distress reflexes and panicked swimming to which a sharks sensory organs are finely tuned to recognize (RCSR, 2001). At the same time, the spearing also introduces blood into the environment, which sharks have evolved the ability to detect in infinitesimally small concentrations in water (RCSR, 2001).
Certainly, sharks are well equipped to make short work of human beings who happen to find themselves at the wrong…… [Read More]
In Paleontology, however, these wing digits have been considered as digits 1, 2 and 3 based on phylogenetic assessment of the fossil lineage suggesting that birds have evolved from theropod ancestors that had lost the fourth and fifth digits. Critics of this theory have suggested that birds have evolved from some other ancestors that had lost the first and fifth digits. Studies of developing limbs of chicken, including a polydactylous variety and mouse have confirmed that the wing digits are actually 1, 2 and 3 and support the hypothesis of theropod descent of birds. (Vargas; Fallon, 87)
The origin of birds from dinosaurs is a fascinating study. The discovery of the first fossil protobird, the Archaeopteryx started most of the studies on the dinosaurian origins of birds. Most paleontologists now agree that birds have descended from a particular line of dinosaurs, the theropods, more specifically the coelurosaurs who had features that were remarkably similar to birds. The study of the skeletal remains of the Archaeopteryx, Anchiornis, Mononykus, Alvarezsaurus and many other fossils have confirmed the hypothesis that birds have evolved from feathered dinosaurs through small evolutionary steps which included small leaps into the air to catch prey followed by swoops which later evolved into steered swoops, glides and finally into full-fledged flight. This process was helped by numerous small skeletal and physiological adaptations that helped in flight as well as ensured survivality of that primitive dinosaur which later evolved into birds. The origins of flight, however, are still debatable with experts differing over cursorial, arboreal and "pouncing proavis theory." There is also considerable debate over the issue of the origin and purpose of the evolution of feathers since feathers have been found in many non-avian dinosaurs as well. Despite all these debates, one cannot discount the fact that there are many characteristics of more than 120 that are shared by both dinosaurs and birds.… [Read More]
LEECHES: Bloodsuckers, Life-And-Limb-Savers
"Nothing works as well as leeches when we need to get blood out of a (body) part."
Blood clotting is a life-saving body process, but when it endangers life or prevents the resolution of a torn tissue, leeches can come in handy. They have shown their worth as natural blood thinners, painkillers and surgical scavengers with the anticoagulant and anesthetic properties of their saliva. These saliva components hold much promise for the "treatment of cardiological and hematological disorders" (Sohn)
These squirmy bloodsuckers, which naturally occurred in ponds in the Medieval period, were used as a panacea for a variety of diseases and disorders in early times. Surgeons and barbers employed these worms in bloodletting, believing that removing some of the blood in an affected part would cure it. It remained useful until the coming of modern medicine, which discarded it, until its reappearance in the last century as a versatile natural waste disposal surgical tool.
Today, the Hirudo Medicinalis species of leech is a reliable last resort when something is needed to overcome the clotting mechanism, something that thins the blood or decongest clots.
Using its two suckers to feed and to hang itself, the leech secretes Hirudin, an anti-coagulant and anesthetic, while it sucks blood from the host. When it has sucked enough, it just falls off from the host and leaves blood oozing fresh from its bite wound.
It works to decongest clots and to keep the blood from clotting at a period long enough to let the surgeon do his work on the patient. It is specifically useful in trauma management and surgery, such as in re-attaching severed body parts or in reconstructing a burned tissue (Polsdorfer). In general, it is of benefit to all procedures involving venous insufficiency, re-plantation surgery (where artery input can be established but not venous drainage), scalp avulsions, periorbital hematomas, heart diseases and breast surgery. Each adult leech can take in up to 15 ml of congested blood and can scavenge for…… [Read More]
Relics of Human Evolution
Vemeonasal organ. The vemeonasal organ is a little pit on each side of the septum that is lined with nonfunctioning chemoreceptors. It may have been used for pheromone-detecting ability.
Extrinsic ear muscles. These three muscles most likely made it possible for prehominids to move their ears independently, in the manner of many mammals, such as rabbits and dogs. Many people can learn to wiggle their ears because of these muscles.
Wisdom teeth. Early humans had to chew a lot of plants to get enough calories to survive, so another row of molars helpful. Today, only about five percent of the population has a functioning set of these third molars, which are often removed to avoid problems when they don't fully emerge or emerge sideways.
Neck rib. A set of cervical ribs appear in less than one percent of the population. They often contribute to nerve and artery problems, and these leftover ribs don't seem to be of much help with regard to movement and flexibility.
Third eyelid. Some common ancestor of birds and mammals may have had a membrane for protecting the eye and that could also have functioned to help sweep out debris. It is believed that humans retain only a tiny portion of this membrane in the inner corner of the eye.
Subclavius muscle. This small muscle stretching from under the shoulder from the first rib to the collarbone has no purpose since humans don't walk on all fours. Some people have one, some have none, and a few have two.
Palmaris muscle. This long, narrow muscle runs from the elbow to the wrist. Only about 11% of modern humans have this muscle. It may once have been important for hanging and climbing. Surgeons harvest it for reconstructive surgery.
Male nipples. This lactiferous ducts form well before testosterone causes sex differentiation in a fetus, causing some scientists to believe that the female version of the body is the basic template. In fact, men have mammary tissue that can be stimulated to produce milk.
Erector pili. The are the bundles of smooth muscle fibers that enable animals to puff up their fur for insulation or to raise their hackles to intimidate others. Humans have retained this ability…… [Read More]
The authors explain that "Large-scale habitat loss and fragmentation…" that results from urban sprawl is a major cause of the lack of biodiversity within the insect species (Acharya, 1999, 27). Even the building of a new road, or street lights, in places where previously there were no roads or lights, what the authors call "undisturbed areas," has an impact on insect biodiversity, Acharya explains. Meanwhile, moths, which are known to be drawn to light, have trigger mechanisms that detect the echolocation signals of bats; and on the other hand bats feed "…heavily" on moths, Acharya continues; in fact many bat species use moths as their "main food item" (Acharya, 27).
The point of that information (and of this study) in this peer-reviewed piece is that if "…eared moths" exhibit behaviors that allow them to avoid bat attacks, they would not be caught as often by bats and hence this would have an effect on bat feeding (28). The authors "deafened" some moths as an experiment to determine of the moths would still be evasive to the echolocation abilities of bats. The authors released 33 "deafened" moths and 80 "eared" moths and none of the deafened moths exhibited evasive behaviors when bats attacked while 47.5% of the moths that could "hear" bats' echolocation did attempt evasive behaviors. And so, while lighting changes bat behaviors and causes bats to alter their normal paths, lighting also interferes with "…a moth's ability to respond to echolocation calls" and hence moths "…suffer a selective disadvantage around lights" -- which ironically is to the advantage of bats (Acharya, 32).
Light dependent shift in the anti-predator response of a pyralid moth
Another research paper dealing with moths and bats is published in the journal Oikos; in this case the authors demonstrated that moths are actually able to "…switch between defensive strategies from insectivorous birds [in the daytime] to bats in the evening" (Svensson, et al., 2003, 239). Moreover, this research places emphasis on what Acharya was explaining in the previous research article: that is, a moth's ability to dive away from a bat -- "a spiral flight towards the ground" which is set in motion by the detection of a bat's echolocation signal -- is "inhibited when the moth flies close to a mercury-vapour streetlamp" (Svensson, 239). This…… [Read More]
In that respect, one of my professional idols was Steve Irwin who was tragically killed in 2006 in an encounter with a sting ray (Webber, 2011). While he was best known for his television show, the Crocodile Hunter, he was actually a world-renowned environmental conservationist who had dedicated his life to protecting endangered animal species and to educating the public about the importance of protecting the natural environmental habitat of wildlife species. According to the Queensland Department of Education and Training (2006),
"Steve had a significant influence on thousands of Queensland school children and his passion for the environment and wildlife was extremely infectious.
worked tirelessly to protect the world's animals and environment. He was awarded the Queensland Museum's highest accolade in 2003 - the Queensland
Museum Medal - for his exceptional contribution to the understanding and appreciation of Australian wildlife at an international level and his commitment and passion to conservation and the environment."
Becoming a Zookeeper
Becoming a zookeeper does not necessarily require any specific advanced degree but the field is highly competitive so it would be advisable to pursue a college degree in a related field such as Zoology, Animal Husbandry, Biology, or Ecology (UoF, 2011). Besides educational credentials, the next most important factor is experience. According to the Jacksonville, Florida Zoo,
"Our Zoo can have up to 100 or more applications for every zookeeper opening here at the Jacksonville Zoo and Gardens. As a result, it is important to know how to separate yourself from the other applicants. Although there are many things considered, it usually comes down to two basics -- experience and education." The best way to get that experience is to volunteer at a zoo.
(UoF, 2011).… [Read More]
Zoo Animal Technology Program
I want to enter the Zoo Animal Technology Program at BLANK University for a number of reasons. First, I have always loved animals since I was very young, and I've always felt I wanted to help take care of them in some capacity as my career. In the past, I've had tropical fish, dogs, cats, hamsters, guinea pigs, rabbits, birds, and other animals in my family for as long as I can remember. I have always been involved in training, maintaining, and caring for these animals, and I have loved every one of them. I would like to continue in my life.
I also strongly believe in animal conservation and husbandry, and the zoo technology program would allow me to learn more about these important areas of zookeeping. I know that many animals are endangered in the wild today, and the only way to help preserve many of these magnificent animals is to house and breed them in the world's zoos. I think that is a very important aspect of zoology that many people do not recognize or appreciate. For example, the panda programs that are breeding successfully at national zoos, including the world famous San Diego Zoo, are good examples of successful breeding programs.
While I love working with animals, I also enjoy working with people, and I know that is a big part of most any job in the zoo. You have to interact with the public, and they can be curious and attentive, so you have to learn patience and understanding of people along with the animals. I think I have those qualities, and I think I would bring good qualifications to a job in a zoo, which is another reason I'm so interested in your Zoo Animal Technology Program. It is important to understand every aspect of the job you're going to do, to see if you're a good fit, and I believe I have done that, and I am a good fit.
In my education so far, I have done well in the sciences, including biology, which I believe gives me a good foundation to build my degree…… [Read More]
Search and Rescue Dogs
Search and rescue is all about saving lives. And the capability to save a life is regularly dependent upon how quickly a person can be found and accessed (National Association for Search & Rescue, 2011). Search-and-rescue dogs are smart, nimble and compliant, but their high drive to want to play is what makes them look for a missing person in all kinds of different places and situations. At its most fundamental, the job of a Search and Rescue (SAR) dog has two components. The first is to find the source of a human scent and the second is to let the handler know where it is (Layton, 2011).
The dogs trained for urban search and rescue, utilize their noses to find living victims who are trapped when disastrous events take place like a building collapsing due to an earthquake, hurricane or explosion. Other SAR dogs are trained in wilderness, avalanche and water searches. Each type of SAR requires specific training. Disaster dogs must be capable to focus on their search while finding their way around large piles of shifting rubble and contending with commotion that may include other search dogs and people, and the existence of cadavers (Mehus-Roe, 2011).
Experts estimate that a single SAR dog can complete the work of twenty to thirty human searchers. It's not just about smell, either, dogs have superior hearing and night vision which also come into play. Time is constantly an issue in search and rescue. In an avalanche condition, for example, roughly ninety percent of victims are alive fifteen minutes after being buried; only thirty percent are alive after thirty five minutes. While most avalanche victims don't survive, their chances increase exponentially when dogs are in on the search. Even in cases where victims are thought to be…… [Read More]
Annelids are members of the Superphylum Lophotrochozoa. The division of the Phylum is in three classes Hirudineans (leeches), Oligochaetes (earthworms) and Hirudinean (Polychaetes and leeches). They inhibit marine aquatic with Parapodia, like nereis Meglitsch P, 1972()
They are worm like animals that have muscular body walls that elongate. They are also circular in cross section. The major difference between Phylum Annelida and other worm like creatures is that, they have segmented bodies (also known as metameric). Each segment has its own particular function. Phylum Annelida include different types of earthworms, leeches and marine polychaetes. There are those that live in fresh water, marine also terrestrial. Some of them live as parasites. Annelids are skilled in swimming, creeping and burrowing Badea, Gagyi-Palffy, Stoian, & Stan, 2010
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Meglitsch P (1972)
, said that Annelids are connected to Molluscs and seem to have arisen from flatworms. Given the characteristics that the Annelida display, they may be the predecessors to arthropods. Meglitsch's arguments are made from the fact that they both have segmentation. Among Phylum Annelida, those consider most primitives and polychaetes though to-date they have been relegated degenerate Badea et al., 2010
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Characteristics of Phylum Annelida
Characteristics that Phylum Annelida possesses which are distinctive from the other worm like creatures are given in this section. Phylum Annelida have no backbones they have cylindrical segmented bodies (metameric). Their digestion is extracellular, meaning they have a complete mouth to anus digestive system with muscular walls such that body movement does not interfere with digestive tract movements Badea et al., 2010
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. They are vascular - meaning they have a well developed circulatory system - with vessels for pumping and distributing substances throughout the body. They are superb in burrowing, swimming and…… [Read More]
In Jamaica, like many other physicians abroad, Sloane collected specimen; later, he acquired the collections of others. Among the botanical material in his collection were exotic plants and bird skins, "unique albums of Durer's prints and drawings" "a vast library of manuscripts and printed books" (Geographical 2003 26+,the second two items of which probably contained abundant botanical engravings.
Not all of the items Sloane collected survived. One that id, however, was cocoa, which he brought back to England and "marketed shrewdly as a medicinal drink valued for its 'Lightness on the Stomach'" (Sterns 2003 411+). The financial incentive was strong in many of the collectors, although with Sloane, it also had a practical side as he went in search of remedies. In 1712, for example, Sloane became keen to purchase the collection of the German physician, Engelbert Kaempfer. A chapter of Kaempfer's book, Exotic Pleasures, mentioned a number of Oriental remedies, along with recipes, including one using the exotic Japanese tea plant, the white opium poppy and cannabis; it was supposed to be good for gout.
As a result of his personal collecting, and his purchase of others' collections, Sloane "managed to mix the simple businessman in him with the simple scientist to produce a remedia composita that cured, among other things, the financial woes of the impecunious Apothecaries" one of which was the Chelsea Physic Garden where he had studied. At some point, Sloane had "become the leaseholder of the land on which the Chelsea Physic Garden was built, and in 1722 he leased the land back to the Apothecaries for the sum of five pounds a year in perpetuity 'on condition that it be kept up and maintained by the Company as a physick garden'" (Sterns 2003 411+). Part of the agreement was that the garden was to convey to the Royal Society fifty plant specimens annually. "By 1796, when the arrangement ceased, the Royal Society had accumulated 3,750 specimens" (Sterns 2003 411+).
This would have been an impetus for botanical artworks, many of which would doubtless have been copies by the engravers and perhaps used in other ways. It was certain, however, that Sloane's collections influenced the painters and designers of the day. "On his death in 1753, his herbarium and Cabinet of Curiosities, the most comprehensive collection in England, was bequeathed to the city of London for a sum far below its worth" (Sterns…… [Read More]
It is common knowledge that the human body consists of about 65% water. People cannot live any longer than five days without H20. Individuals of all ages love to sail the oceans, swim in the sea and soar under or speed across the waves. It comes as no surprise, then, that some part of the human psyche remembers millions and millions of years ago before animals came on shore. What is still questionable is how or why these animals made the move from water to land. The journal articles discussed below give some of the latest findings on this topic.
Early in the Devonian Era, close to 400 million years ago, all the continents were grouped closely together and surrounded by the seas. The climate ranged from dry weather to torrential rains as some tropical areas do today. Even flowers had not yet evolved on land, let alone vertebrates. Many of the sealife were preparing for that next big step onto land with lung-like organs that would later evolve into swim bladders to control buoyancy. Some of these creatures moved on lobed fins or fleshy appendages that supported their weight while crawling underground. In time, they adapted to terrestrial life and evolved into amphibians with fully developed legs.
In what kind of environment did the transition to lobed fin first occur? This has recently been a "bone" of contention. Marine biologists Graham and Lee understand that air-breathing fishes may be seen as possible models for the Paleozoic evolution of vertebrate air breathing and the transition to land. They note how recent studies suggest that marine air-breathing amphibious fish in tropical, high intertidal zone habitats are analogs of early tetrapods and that the intertidal zone are feasible early habitats for the Devonian land movement by vertebrates.
However, in response to such scientists, Graham and Lee argue that selection pressures imposed by life in these intertidal zones are insufficient to have led to the necessary respiratory capacity or break from water required for the vertebrates to move to land. The marine amphibious fishes, which occur mainly on rocky shores or mudflats, have reached what the authors call "their land-penetration" limits and remain linked to water by…… [Read More]
Double Crested Cormorant "are opportunistic, generalist feeders" (Wires, Cuthbert, Dale, & Joshi, 2001). They feed on slow moving fish species that range from 3 centimeters to 40 centimeters. These birds forage in shallow water and seem to be strict diurnal in the way they eat. They are quick to respond to areas with high fish concentration and flock where the fish can easily be caught.
The Double Crested Cormorant breeds in cold climatic conditions and has been living in Alaska for a long time (Wires, Cuthbert, Dale, & Joshi, 2001, p. 36). According to Siegel-Causey & Savinetskii (1991), the remains of the bird have been found on Amchitka Island dating back over 2000 years. These remains suggest that the there were plenty of the species in the central Aleutian Islands and climate changes have reduced their population in Alaska.
Great Blue Herons
Great Blue Herons are prey generalists, although they forage for fish. They catch their prey as they walk along the shores of water bodies such as oceans, lakes, marshes and even rivers. On the mainland, the bird preys on small animals such as rodents (Butler, 1992). The mainland foraging is done in the winter when the shores are frozen and fish is unavailable, or when the young ones are learning hunting skills (Butler, 1991). The Great Blue Herons also prey on amphibians, reptiles, invertebrates and birds. They catch their prey by a quick head and neck thrusts.
Great Blue Herons breed in various regions of the world, but in North America, the Ardea Herodias occidentalis are found in the warmer regions such as Florida. "The Herodias fannini are non-migratory found in the Pacific coast from Washington States to Alaska and Herodias found between south Canada to Galapagos" (Butler, 1992). The size of the colony on all these species depend on foraging area.
Wood storks are specialists. They have a specialized eating behavior known as tactolocation, they walk through the water with beaks open and immersed in the water. When they feel the preys, they snap…… [Read More]
Behavioral Episodes in Relation to Leopard Seals
Leopard seals are widely known for their ferocity and have been acknowledged as top predators for a long time now. These are large but slender mammals, with females usually exceeding males in size and weight. The spotty coats, distributed along their bodies, define the leopard appearance and allure to the hunting abilities they possess. With powerful jaws and canine teeth, leopard seals can prey on creatures of whatever size. Their agility and reputation have long formed individuals' negative perception upon the former. This document is to try to dismantle the negative image leopard seals have been inoculated with for such a long time. This proposal looks at some of the facts that have led people forming drastic opinions as well as some episodes that appear to indicate how little we may in fact know in relation to leopard seals.
Statement of Problem
Explorers in the Antarctic have often expressed their opinions as to the dangerous nature of leopard seals (De Laca et. al, 1975, p. 85). Threat displays, unexpected attacks, these have all been familiar to researchers since the first Antarctic expeditions. In 2003 however, when a leopard seal attacked and furthermore, drowned a marine biologist, all expeditions were delayed temporarily. Never before had a leopard seal killed a human being. This was concerning for all explorers since it became obvious that precaution measures needed to be evaluated and updated.
I propose to review some relevant information in relation to the unpredictability of the leopard seals. Hence, the following leads will be considered:
1. provide general information in regard to leopard seals that will relate to the mammals' hunting abilities.
2. indicate that it was unusual that a leopard seal killed a human being and that this is not a specific behavioral pattern.
3. present a relevant case that leopard seals can indeed be opened to interactions with human beings.
Use of sources
The two main sources that provided the information necessary to conduct this inquiry come from the Antarctic Journal of the United States and Antarctic Science. Both are articles, the former by De Laca, T.E., Lipps J.H., and Zumwalt G.S., and the latter by Muir, S.F., Barnes, A., and Reid, K., focusing…… [Read More]
Thoreau was a student of nature for virtually all of his adult life. During Thoreau's life, Cape Cod was a relatively unspoiled area rich with nature and people who worked closely in nature, such as farmers and fishermen. Those who lived on Cape Cod tended to be independent sorts, and Thoreau preferred their company to those of people engaged in commerce or other business-related occupations.
In his small book Cape Cod, Thoreau recounts his experiences on walking excursions around Cape Cod during the mid-1800's. In the process he described much about the unspoiled nature present throughout the Cape at that time.
In the opening chapter Thoreau talks about the ecology of living along the ocean: in the midst of a desperate sight - the wreck of a boat loaded with immigrants, most of whom drowned, he saw people gathering seaweed to use as fertilizer. The seaweed had been tossed up on the shore by the same storm that sank the ship. Thoreau valued such practical use of what nature had to offer.
His unusual perspective about both people and nature is revealed in this sentence: "I sympathized rather with the winds and waves, as if to toss and mangle these poor human bodies was the order of the day. If this was the law of Nature, why waste any time in awe or pity?" The statement seems insensitive but reveals his deep love of nature in all its forms.
Throughout the book, Thoreau notes things that we would celebrate today, such as exceptionally clean water. He describes swimming in such water with great delight, and comments on the fish he can see clearly swimming around his feet. This suggests that fish were more bountiful then than now, as well as the water cleaner. He also notes the thorn-apple growing around the edges of a small island, suggesting an ecological balance, with the plant helping fight the erosion of the little island.
As Thoreau begins the walking portion of his trip, he describes the effects of the environment - a sand bar thrust out into the ocean - on the plants of the area. He describes the area as barren, with few trees except for occasional isolated trees and apple groves. He notes how the windswept nature of the land affected development of the trees. Many had flat tops…… [Read More]
Vombatus Ursinus Organism Profile
Vombatus ursinus is the scientific name given to the organism commonly known as the common Wombat (Matthews & Green, 2012). The common wombat is also referred to as the bare-nosed wombat, or coarse-haired wombat. There are three subspecies of wombats namely Vombatus ursinus hirsutus, Vombatus ursinus tasmaniensis, and Vombatus ursinus. The common Wombat is mainly found in Flinders Island of the Bass Strait Islands. Wombats prefer living in the temperate forest areas of southern Australia. They tend to avoid rainforests, and they are mostly found in the mountainous areas. In Tasmania and South wales, Wombats are found at lower attitudes win open vegetation like woodlands, heathland, and coastal scrub. Wombats prefer to dig their shelters on slopes above gullies and creeks, and they feed in grassy clearings. Wombats are native to Australia, and they belong to the Vombatidae family. Many people have noted that the wombats appear to be smiling because of their huge teeth. Wombats have a lifecycle of 12 years, and they breed any time during the year provided the climate is favorable.
The common wombat will range between 75-85 cm in length and weigh around 20kg. However, wombats are known to reach up to 35 kg and 1.2 meters. The body of a wombat is squat and bearlike with small ears and eyes and a large nose. Wombats have powerful shoulders and a small tail around 25 mm in length that is hidden by fur. Their fur can be grey, brown, or black, but most of the time the fur is colored in dirt. Wombats have large paws and claws that they use for digging. They differ from other marsupials because in their upper jaw they only have two incisor teeth. The common distinguishing features of a common wombat are large and naked nose, short slightly rounded ears, and coarse, thick coat.
Wombats generally give birth to a single young called a joey, but twin do occur in rare cases. The gestation period of a wombat is between 20-22 days. According to Story, Driscoll, and…… [Read More]
Agassiz continued to find evidence for his ice age hypothesis when he traveled to North America in 1846. He was welcomed warmly in America, and was soon put in charge of building the Museum of Comparative Zoology at Harvard, where he also assumed a professorship (Duffin, 2007). The museum opened in 1860, and had the distinction of being the first publicly funded museum of science in North America (Berkeley). Agassiz worked tirelessly to promote scientific education in the United States. In 1863, he was a founding member of the new National Academy of Sciences, and in the same year was appointed a regent of the Smithsonian Institution (Ibid.).
In 1873, just a few months before his death, Agassiz founded the first American marine biology laboratory on the island of Penikese in Massachusetts. The primary goal of the laboratory was two-fold: to be a venue for new research, and, more importantly to Agassiz, to teach methods of observation in natural history to secondary school teachers, ensuring the further dissemination and proliferation of this relatively young field (Benson, 1988). Agassiz endowed the project with his own passion and his own education philosophy, stenciling the door of the main laboratory with his own motto: "Study nature, not books" (Ibid.).
His sudden death doomed the project, which lasted only one year before closing. However, Agassiz's lab at Penikese is largely considered the "spiritual father" of the famous Marine Biological Laboratory in Woods Hole, which is now the premier marine laboratory in North America (Zirkle, 1946). The Penikese laboratory was the first institution in the Americas founded for the sole purpose of study marine biology in its natural habitat (Benson, 1988). In this sense, Agassiz can be considered the father not only of the natural history approach to marine biology, but also of marine biology education in the United States.
When he died in 1874, Agassiz was widely respected as a scientist, writer, and educator, and he continues to be to this day. However, there was one blemish in his legacy that has stymied his full acceptance into popular culture in the United States. Agassiz's whole-hearted commitment to the theory of special creation made him a lead dissenter in the debates about evolution in the mid and late 19th century. His theories had profound…… [Read More]
Kennedy announced the formation of a special government group to investigate the use and control of pesticides under the direction of the President's Science Advisory Committee (Rachel pp). The book caused a firestorm of public outrage and sold more than a quarter million copies by the end of 1962 (Rachel pp). United State Supreme Court Justice William Douglas called it "the most important chronicle of this century for the human race" and Loren Eisely of the University of Pennsylvania described it as a "devastating, heavily documented, relentless attack upon human carelessness, greed and irresponsibility"(Rachel pp). The fervor of the favorable reviews were matched by the intense attacks of the chemical industry and those it influenced, such as the president of the Montrose Chemical Corporation, the nation's largest producer of DDT, who asserted that Carson had written not "as a scientist but rather as a fanatic defender of the balance of nature" (Rachel pp). Critics labeled her a food-faddist, nature nut, and fish-lover, and despite poor health, Carson responded to these attacks by speaking to organizations, testifying at Congressional hearings, appearing on special televised segments of CBS Reports, and conferring with President Kennedy and his Science Advisory Committee (Rachel pp). On May 15, 1963, the President's Science Advisory Committee made public its report on pesticide use and control, it confirmed every point highlighted in "Silent Spring" (Rachel pp). The very next day, a sub-committee of the Senate Committee on Government Operations met to conduct a two-year investigation of government and industry regulations regarding pesticides (Rachel pp).
Rachel Carson died on April 14, 1964 at the age of fifty-six from breast cancer that had been diagnosed four years earlier (Rachel pp). Before she died she received many honors, including the Schweitzer Medal of the Animal Welfare Institute, the National Wildlife Federation's 'Conservationist of the Year,' and was the first woman to receive a medal from the National Audubon Society (Rachel pp). And in 1980, Carson was posthumously awarded the highest civilian decoration in the nation, the Presidential Medal of Freedom, accompanied with the words:
Never silent herself in the face of…… [Read More]
Apart of this macroeconomic force of which he was a part, was a Europe-wide banking network that facilitated not only international trade, but also state making elsewhere. He financed the Florentine intellectual and artistic breakthroughs we now refer to as "the Renaissance."
Cosimo's power was greatly respected, and by 1434 foreign princes went to Florence to work out international relations. Machiavelli, nearly a century later, still regarded the Medici family as the harbinger of everything good and evil in Florentine life to Cosimo's "deep and ruthless machinations." Despite the influence of Medici, he is portrayed as indecisive and in the background of affairs: "Cosimo was anxious to remain in the background, hiding his great influence, and acting, when need arose, through a deputy. As a result, very little is known of the measures for which he was directly responsible." Cosimo did not expect eternal rule, nor did he ever give a public speech. After 1434, Cosimo appeared increasingly reactive to events around him, seldom offering explanations for his actions. Typically, his actions served his diverse interests.
The Renaissance in Florence was not a period of individualism. Household relationships were typically, but not always, very strong. The turbulent times reinforced defensive cohesion among family units. To define elite in this period is difficult, for this is a large difference between the political and economic elites, partially due to the volatility in international markets. The Medici family in particular had various allegiances based on partisanship and family ties. The central most faction of the Medici party was extraordinarily centralized in a simple, "spoke" network system. The Medici's, therefore, were more cohesive and centralized than the looser and more-cross pressured oligarchies of the time.
The Medici party -- the most active and centralized faction of the clan -- was an impressively centralized patrimonial machine, with discipline and "top down" control. Some of the micromechanisms important to Medici's power are as follows: a spoke structure resulted in dependence of partisans on the Medici for access to other elites. Communication among other elites, also, had to pass through the Medici; marriage among geographically distant patricians, and other mechanisms. Cosimo Medici did not design his centralized party. Likely, he did not plan on taking over the state. The Medici's were not tactical revolutionaries,…… [Read More]
Another psychological approach studied the physical basis for emotion. LeDoux (1995, p. 209+) noted, "Scientists concerned with human nature have not been able to reach a consensus about what emotion is and what place emotion should have in a theory of mind and behavior." He proposed, however, that "findings about the neural basis of emotion might also suggest new insights into the functional organization of emotion that were not apparent from psychological findings alone. The brain, in other words, can constrain and inform our ideas about the nature of emotion." This would seem to play into any discussion of genetics vs. culture as emotion is viewed, accurately or not, as a construct of societal norms in large part. Because fear is a common part of human life, LeDoux uses it to investigate his theories. "The expression of fear is conserved to a large extent across human cultures and at least to some extent across human and nonhuman mammalian species, and possibly across other vertebrates as well" he notes, which would indicate that fear is not cultural, in fact, but physical, gene-based rather than a product of society. On the other hand, he also encompasses the familiar Pavlovian model in his thinking.
Fear conditioning is a form of Pavlovian (classical) conditioning. Pavlov is best remembered for his studies of alimentary conditioning, in which he elicited salivation in dogs by presenting stimuli that had been associated with the delivery of food (Pavlov 1927). He also determined that animals will exhibit conditioned reflexes that allow them to protect themselves against harmful stimuli by responding to warning signals. Pavlov referred to the latter as defense conditioning (LeDoux, 1995, p. 209+).
Again, this seems to argue for genotype as being less important than phenotype; on the other hand, while there is obviously a physical basis for fear to occur, the experience of fear -- when, where, why and how -- would seem to depend upon environmental -- that is, conditioning -- factors.
Writing in the same journal, Annual Review of Psychology, Suh (2002) seems to arrive at a different conclusion. Suh noted that "Ecologies shape cultures; cultures influence the development of personalities" (2002). In short, he accepts a priori that culture shaped personality; it would be a short leap from there to conclude that personality determined behavior. Thus, in that equation, phenotype does indeed determine…… [Read More]
The Vygotsky influence has recently had an impact in a university environment in New Zealand. Indeed, the application of the ZPD model in New Zealand moved well beyond just another theory for "old school" teachers to bravely tackle, and has actually become a "common sense" approach to learning and development. This information comes through another peer-reviewed research article ("Vygotsky's Zone of Proximal Development and Problem-based Learning: linking a theoretical concept with practice through action research"). In the piece, the author explains that students had been employing "problem-based learning" (PBL) methods to develop "relevant content knowledge and the metacognitive skills that will enable them to become good learners and problem-solvers..." (Harland, 2003).
In this instance, PBL had been providing a needed challenge to the "traditional teacher's role" in that teaching was by way of becoming more like "research supervision" or "mentoring" then actually teaching. Indeed, Harland writes that PBL has been called "an ideology routed in the experiential tradition" because it is altogether capable of being "modified" by individual teachers.
Getting back to a point made earlier in this paper about teachers who have a difficult time abandoning conventional, comfortable methods of instruction - in this case the setting is in New Zealand - PBL was seen as different and refreshing because "most teaching was still organized along traditional lines," Harland explains. The teacher was (and in too many cases still is) the "expert," and hence, the "creator and disseminator of knowledge." But by employing a PBL system, which Harland says takes "a good deal of courage" for the teacher - albeit in the meantime it helps revitalize the educational environment - a teacher can "turn these cultural norms upside down." Harland, the author of this piece, who is also the instructor in question, indicates that his zoology field course had become a "full PBL module" - but after a couple years the capacity for "development and change" within the zoology model "had slowed considerably." It was time for ZPD to make its debut.
Indeed, as soon as Harland was introduced to Vygotsky's ZPD, it "struck" him, he writes, as a "set of common sense ideas that might provide a possible explanatory framework for PBL, and new input into our action research."…… [Read More]