50 Million Years of Horse Evolution

50 Million Years of Horse Evolution Apart from a couple of bothersome side branches, horse evolution presents a neat, orderly picture of natural selection in action. The basic storyline goes like this: as the woodlands of North America gave way to grassy plains, the tiny proto-horses of the Eocene epoch (about 50 million years ago) gradually evolved single, large toes on their feet, more sophisticated teeth, larger sizes, and the ability to run at a clip, culminating in the modern horse genus Equus. There are a number of prehistoric horses, including 10 essential prehistoric horses to know. As part of the evolution of horses, you should also know the recently extinct horse breeds. This story has the virtue of being essentially true, with a couple of important ands and buts. But before we embark on this journey, its important to dial back a bit and place horses in their proper position on the evolutionary tree of life. Technically, horses are perissodactyls, that is, ungulates (hoofed mammals) with odd numbers of toes. The other main branch of hoofed mammals, the even-toed artiodactyls, are represented today by pigs, deer, sheep, goats, and cattle, whereas the only other significant perissodactyls beside horses are tapirs and rhinoceroses. What this means is that perissodactyls and artiodactyls (which counted among the mammalian megafauna of prehistoric times) both evolved from a common ancestor, which lived only a few million years after the demise of the dinosaurs at the end of the Cretaceous period, 65 million years ago. In fact, the earliest perissodactyls (like Eohippus, the earliest identified common ancestor of all horses) looked more like small deer than majestic equines! Hyracotherium and Mesohippus, the Earliest Horses Until an even earlier candidate is found, paleontologists agree that the ultimate ancestor of all modern horses was Eohippus, the dawn horse, a tiny (no more than 50 pounds), deer-like herbivore with four toes on its front feet and three toes on its back feet. The giveaway to Eohippus status  was its posture: this perissodactyl put most of its weight on a single toe of each foot, anticipating later equine developments. Eohippus was closely related to another early ungulate, Palaeotherium, which occupied a distant side branch of the horse evolutionary tree. Five to ten million years after Eohippus/Hyracotherium came Orohippus (mountain horse), Mesohippus (middle horse), and Miohippus (Miocene horse, even though it went extinct long before the Miocene epoch). These perissodactyls were about the size of large dogs and sported slightly longer limbs with enhanced middle toes on each foot. They probably spent most of their time in dense woodlands, but may have ventured out onto the grassy plains for short jaunts. Epihippus, Parahippus, and Merychippus- Moving Toward True Horses During the Miocene epoch, North America saw the evolution of intermediate horses, bigger than Eohippus and its ilk but smaller than the equines that followed. One of the most important of these was Epihippus (marginal horse), which was slightly heavier (possibly weighing a few hundred pounds) and equipped with more robust grinding teeth than its ancestors. As you might have guessed, Epihippus also continued the trend toward enlarged middle toes, and it seems to have been the first prehistoric horse to spend more time feeding in meadows than in forests. Following Epihippus were two more hippi, Parahippus and Merychippus. Parahippus (almost horse) can be considered a next-model Miohippus, slightly bigger than its ancestor and (like Epihippus) sporting long legs, robust teeth, and enlarged middle toes. Merychippus (ruminant horse) was the largest of all these intermediate equines, about the size of a modern horse (1,000 pounds) and blessed with an especially fast gait. At this point, its worth asking the question: what drove the evolution of horses in the fleet, single-toed, long-legged direction? During the Miocene epoch, waves of tasty grass covered the North American plains, a rich source of food for any animal well-adapted enough to graze at leisure and run quickly from predators if necessary. Basically, prehistoric horses evolved to fill this evolutionary niche. Hipparion and Hippidion, the Next Steps Toward Equus Following the success of intermediate horses like Parahippus and Merychippus, the stage was set for the emergence of bigger, more robust, more horsey horses. Chief among these were the similarly named Hipparion (like a horse) and Hippidion (like a pony). Hipparion was the most successful horse of its day, radiating out from its North American habitat (by way of the Siberian land bridge) to Africa and Eurasia. Hipparion was about the size of a modern horse; only a trained eye would have noticed the two vestigial toes surrounding its single hooves. Lesser known than Hipparion, but perhaps more interesting, was Hippidion, one of the few prehistoric horses to have colonized South America (where it persisted until historical times). The donkey-sized Hippidion was distinguished by its prominent nasal bones, a clue that it had a highly developed sense of smell. Hippidion may well turn out to have been a species of Equus, making it more closely related to modern horses than Hipparion was. Speaking of Equus, this genus- which includes modern horses, zebras, and donkeys- evolved in North America during the Pliocene epoch, about four million years ago, and then, like Hipparion, migrated across the land bridge to Eurasia. The last Ice Age saw the extinction of both North and South American horses, which disappeared from both continents by about 10,000 BCE. Ironically, though, Equus continued to flourish on the plains of Eurasia and was reintroduced to the Americas by the European colonizing expeditions of the 15th and 16th centuries CE.

StilSim Personnel Strategy Formulation Essay Example | Topics and Well Written Essays - 2250 words

StilSim Personnel Strategy Formulation - Essay Example By staying in the business of staffing solutions, they are trying to match a demand supply gap for employment that exists from time to time within the economy (StilSim Personnel, 2007). SWOT Analysis Strengths StilSim Personnel has been in the staffing solutions for over 25 years. So naturally, it can be estimated that at least as of current scenario they still have some faithful and loyal customers in the market. StilSim Personnel boasts of a strong customer service, which helps them in maintaining in steady flow of returning customers. Weakness Decline in profits and monthly performance statements affecting the company’s top line growth and overall performance of the company as compared to others in the market Fighting within employees, cold tensions existing among employees thereby leading to low employee morale and affecting company motivation A strong sense of over confidence exists with the Customer Service, which the company provides to its customers Opportunities In th e age of today’s fast changing business environments, big corporations are increasingly looking for temporary staffing of their variable demands. They don’t want to retain employees for the long run, when the demand for manpower is low and so is very much in favor of temporary staffing. As of today’s date, 90 % of the corporations and enterprises, big or small are looking into temporary staffing to fill up their variable short time manpower needs. Though, StilSim Personnel has a division to deal with temporary staffing, but taking the business on the internet and integrating the temporary staffing division on the worldwide web will help the company to meet the demands of big corporations, while being able to show an impressive performance in the monthly... StilSim Personnel has been in the staffing solutions for over 25 years. So naturally, it can be estimated that at least as of current scenario they still have some faithful and loyal customers in the market. StilSim Personnel boasts of a strong customer service, which helps them in maintaining in steady flow of returning customers. Decline in profits and monthly performance statements affecting the company’s top line growth and overall performance of the company as compared to others in the market Fighting within employees, cold tensions existing among employees thereby leading to low employee morale and affecting company motivation A strong sense of over confidence exists with the Customer Service, which the company provides to its customers In the age of today’s fast changing business environments, big corporations are increasingly looking for temporary staffing of their variable demands. They don’t want to retain employees for the long run, when the demand for manpower is low and so is very much in favor of temporary staffing. As of today’s date, 90 % of the corporations and enterprises, big or small are looking into temporary staffing to fill up their variable short time manpower needs. Though, StilSim Personnel has a division to deal with temporary staffing, but taking the business on the internet and integrating the temporary staffing division on the worldwide web will help the company to meet the demands of big corporations, while being able to show an impressive performance in the monthly performance statements.

Richard-Campbell Sleep Questionnaire Instrument Critique Research Paper

Richard-Campbell Sleep Questionnaire Instrument Critique - Research Paper Example In the development of the instrument, studies describing critically ill patients’ patterns of sleep were used as a theoretical basis for various items incorporated into the instrument. The instrument was validated against the polysomnograph and found to be an improvement in measuring sleep quality for patients in intensive care (Richards et al, 2000). As currently used, the Richard-Campbell Sleep Questionnaire reflects five items that are used for measuring sleep quality in ICU patients. These are the depth of sleep, ability to fall asleep, number of times the patients wake up, percentage of the time the patients are awake, and the overall sleep quality of the patients (Richards et al, 2000). The Richard-Campbell Sleep Questionnaire, on top of these five items, also includes a rating for noise during the nighttime, which are scored using a visual analogue scale. The five scores for the Richard-Campbell Sleep Questionnaire is averaged, and the mean score used in determining sleep quality. Night shift nurses are required to complete the Richard-Campbell Sleep Questionnaire with regards to the sleep quality of their patients overnight, while the patients also fill in the Richard-Campbell Sleep Questionnaire after they wake up. The instrument was modified to measure how many awakenings the patient had during their sleep in order to d ifferentiate between patients who woke up frequently and those who did not wake up during their sleep. Further advances in the instrument involved the requirement that the items and directions on the questionnaire be read out to the patients in intensive care (Richards et al, 2000). This was because, while patients have been found to have little trouble in completing it if nurses read the items and directions out to them, majority of the critically ill patients had problems when completing the questionnaire without provision of assistance. However, for obvious reasons, this survey is only useful if the patients are awake and non-delirious. The visual analog nature of the Richard-Campbell Sleep Questionnaire scales means that, as a measure of the latency of sleep, it is not very sensitive in comparison to other modalities of scaling (Richards et al, 2000). For this reason, there is a need to revise the instrument. This could be done in order to improve the Richard-Campbell Sleep Ques tionnaire’s ability to predict the efficiency of sleep in intensive care patients. For example, the instrument could be revised by adding more items in an attempt to predict sleep efficiency with an improved percentage of variance. However, this will be done at the risk of decreasing the practicality of outcome measurements for patients who are critically ill (Richards et al, 2000), especially as increasing the number of items may be too much for nurses who are overworked and patients who are critically ill and may be too weak to answer them. The Richard-Campbell Sleep Questionnaire’s predictive ability could also be potentially improved by adding another section with more items for nurses. This additional section would consist of additional observations that the nurses make for the critically ill patients’ quality of sleep (Richards et al, 2000). The Richard-Campbell Sleep Questionnaire could also be revised to account for sleep characteristic

Patterns of Dominance Essay Example for Free

Patterns of Dominance Essay The Jews have experienced a number of atrocities in their history. Yet, they are still bound together by their Jewish identity. Although religion plays a crucial role in the lives of Jews, they are best characterized as an ethnic group facing discrimination in a lot of ways in different places. The most extreme form of anti-Semitism had been the expulsion of the Jews from various countries such as England, Spain and Portugal in previous centuries; as well as the execution of the Jews in Germany, more commonly known as the Holocaust. Although religion plays a very important role in the lives and the culture of Jews, they can still be collectively looked at as an ethnic group experiencing discrimination and outright hatred all over the world. Because For one, they still strongly adhere to a common ancestry and lineage. Jews have also managed to protect their collective identity through the years. Other religions embrace a multiplicity of ethnicity and race while the religion of Jews seems to be an extension of their ethnicity. Converts tend to be embraced by the Jewish and integrated into their ethnicity. Patterns of anti-Semitism have changed over time. Gone are the days when governments would enable rules and legislations expressly banning Jews certain rights and privileges in society. Yet, covert discrimination is still felt by Jews, especially in Europe where graffiti and verbal attacks against them proliferate. These forms of â€Å"unofficial† discrimination are more difficult to deal with than the kind which is officially sanctioned by governments (Morris, 2001). Jewish Identity in the United States In the United States, Jews have relatively more freedom as a group of people than in New York. This perception led them to migrate in waves from European countries to the United States since the early nineteenth century. Ironically, there is roughly the same number of Jews in the United States and in Israel. While the Jews represent 80 percent of the population of Israel, in the United States, they only hold two percent of the total population. In addition to this, American society is greatly diverse and Jews have a tendency to be subsumed in the mainstream culture. The American society has welcomed Jews but they are not very interested with their heritage (Langman, 1999). Due in part to the secular nature of American society, more and more Jews are de-emphasizing their Jewish roots and heritage. The American society is also highly individualistic in contrast to the emphasis of Jews on the importance of community and family. As Jews are assimilated more and more by the American society, they tend to rely less on their Jewish tradition and identity. There is less observance of religious activities and less loyalty to the concept of Jewish identity. This is further confounded by an attitude of pluralism and multiculturalism in the United States. Because of these processes, the importance of family in Jewish life cannot be underestimated. As the larger society seeks to integrate and assimilate the Jewish identity, the family remains the bastion of ethnicity socializing young Jews into their identity and enables them to look at who they are and what make them unique as Jews. As they grow up, traditions and Jewish practices are drilled into young Jews so that they understand who they are in the context of a multicultural and highly pluralistic American society. If such influence of the family weakens, then the Jewish identity also weakens. Women’s Position and Oppressed Racial and Ethnic Groups Women have been one of the oppressed and marginalized groups through history. Only recently have they been granted suffrage and equal footing with men in terms of opportunities and privileges in the society. Their situation is different from other marginalized groups in society because women oppression transcends cultures and societies all over the world. In a number of cultures and societies all over the world, women have been considered as second class citizens who cannot enjoy the same level of privileges and rights as men. These rights included access to education, freedom to choose their own lifestyle and directions in life. In addition to these, they have been subject to oppression and assault including sexual harassment and rape, pornography, illicit sex trade, and physical abuse. Women’s experience is different from racial and ethnic minorities because they are oppressed for something that is fundamental to their identity and their sex. In earlier times, they have been considered as the property of men. This experience is similar to the Black slaves who did not have rights in the American society. They were sold and treated like machinery. African Americans have been granted emancipation and their rights as citizens of the United States. Women have been granted suffrage at a later time. Women’s rights is a worldwide phenomenon and most governments have recognized the need to grant women equal rights with men. The difference with ethnic oppression is that they are confined to individual countries. Both of these oppressed minorities, however, still suffer from covert racism brought about by the social systems that favor one group over another. Women’s Rights Movements in the Twentieth Century In the twentieth century, women in the English speaking world have become more active in fighting for equal rights. From issues of suffrage and equal opportunities for work, the women’s rights movement or feminist movement has come to embrace added issues that affect the situation of women in society. Such issues include access to employment opportunities, promotion at work and access to various services at work to accommodate their situation. The issue of abortion and the choice of women in keeping their babies or not is another hotly debated issue in women’s civil rights in the twenty first century. Women’s situation at work is different from men because women go through different life stages and processes that may appear to disrupt their work. They get pregnant and have to file maternity leaves. After that, they also have to nurse their babies and make sure that they grow up. Because of this reason and other systems of overt and covert discrimination, men tend to be promoted to higher positions more than women. In the United States, more women tend to work and this has also affected the American family. For one, women have to look after their work as much as men, yet they also have to be mothers and look after the babies as they grow up. With increasing work demands, it becomes more difficult for women to balance their time with their families. In addition to this, highly driven women may even put their career over their family. Such attitude clashes with the traditional view that women should be at home looking after the kids and how they grow up. In the long run, if the husband will become dissatisfied, then divorce and separation may ensue. Stereotyping of the Aged, People with Disabilities and Gays and Lesbians The tendency for the dominant group in the society is to stereotype marginalized groups in the society. Age people tend to be seen as weak and bordering on being obsolete and anachronistic. This is because they lack the usual energy and technological savvy of younger workers. As a result of this stereotype, they are being replaced by younger employees. People with disabilities on the other hand, tend to generate sympathy but at the same time discrimination. Through the special treatment that shown to them, they are in effect being told that they cannot do the activities and the things that people without disabilities could do. Gays and lesbians, on the other hand, tend to be seen from the dominant moral code in the society. As such, they are judged too often as immoral persons in the society and should therefore be despised. When people despise them, their good side is often disregarded completely. To combat unfair practices at work and in the society, the aged, people with disabilities and gays and lesbians should be mobilized so that they can protect their rights. Of these groups, however, gays and lesbians tend to be the most empowered because they are relatively braver in banding together and fighting for their rights. The aged and the persons with disabilities tend to be silent about their experiences. As such, they cannot effectively fight for their rights. Furthermore, gays and lesbians tend to be more educated in regards to their rights so they have better leverage than the aged and the persons with disabilities in fighting for their rights. The dominant group in the society can make it harder for these people to band together so that they can effectively fight for their rights.

The Tree of Knowledge in Frankenstein by Mary Shelley Essays -- Franke

The Tree of Knowledge in Frankenstein by Mary Shelley In Frankenstein, Mary Shelley warns that with the advent of science, natural philosophical questioning is not only futile, but dangerous. In attempting to discover the mysteries of life, Frankenstein assumes that he can act as God. He disrupts the natural order, and chaos ensues. Mary Shelley goes to great lengths to emphasize the beauty and order of life when man engages in à ¬naturalà ® pursuits. She idealizes Frankenstein's home life: à ¬I feel exquisite pleasure in dwelling on the recollections of childhood, before misfortune had tainted my mindà ® (38). His family is orderly and wonderful. Clerval's à ¬presence brought back to my thoughts my father, Elizabeth, and all those scenes of home so dear to my recollectionÃâ€"I felt suddenly, and for the first time during many months, calm and serene joyà ® (58). Shelley also stresses that man should feel at one with nature, not at odds with it: à ¬When happy, inanimate nature had the power of bestowing on me the most delightful sensationsà ® (68). Certain occupations allow man to be at one with nature and his fellow creatures. Shelley feels that science should be useful and beneficial to mankind. Clerval, a clearly pure and benevolent character, studies languages. He loves poetry. These disciplines allow man to help others and glorify nature without questioning it. In childhood, Frankenstein's studies contained à ¬bright visions of usefulnessà ® (38): à ¬I betook myself to the mathematics, and the branches of study appertaining to that science, as being built upon secure foundations, and so worthy of considerationà ® (41). But Frankenstein's interests soon turned away from mathematics; he speaks of his change of mind as i... ...gnorant art thou in thy pride of wisdom! Cease; you know not what it is you sayà ® (194)! Frankenstein has finally learned his lesson. Or has he? After his excruciating pains and hardship, Frankenstein's dying words are: à ¬I have myself been blasted in these hopes, yet another may succeedà ® (210). Unless Frankenstein is referring to beneficial, pragmatic scientific knowledge, then he has not yet acknowledged that man cannot know the secrets of nature. Shelley means his final words to be a warning to the reader. Man's growing ambition and intellect will render him desperate to discover the deepest mysteries of lifeà ³it is a difficult task to halt this ambition. But this ambition is greater than man's intellect. He can never know all, though he aspires to heaven. Until he realizes his limitations, the spread of science can only lead to chaos and destruction.

I’Ve Witnessed the Arrival of a Golden Age Essay

The article â€Å"I’ve witnessed the arrival of a golden age† was published 14th August, 2007 and written by the Guardian’s Delhi correspondent, Randeep Ramesh. Throughout the article, Randeep Ramesh describes the development of India. Among other things he tells the story about some years ago when he visited an Indian software millionaire, who shows him around the computer industry. The software millionaire comments on the correspondents’ education, because he thinks it is a shame that he was not born in Indian for that cause that the British system makes scientists become journalists instead. The headline, â€Å"I’ve witnessed the arrival of a golden age† is mainly factual, because it informs us. It actually tells that the writer has witnessed a golden age and what we will find within. The language which is used is formal or rather a quotation. It tells us what we will find within. The structure of this article is basically like any other article. It is structured with a lot of sections. It has a headline and beneath it there are three sentences which briefly give the reader a general idea of what the article is about and then a little introduction which is an experience where a software millionaire shows him around. The memories from his past are mentioned. Then it moves on to the body of the article which is a description of how India has developed and how he had witnessed the arrival of the golden age while he was living in Delhi. The body only sticks to one topic and that is India. In the ending there is a sum up which also solve the problem in the article. Besides that there is an interesting point in the three last sentences. That is, you see that India has put the past behind and now see a bright future coming and still is optimistic. The writer does not use a figurative language. Many of the sentences are long and some complex etc. â€Å"In the unselfconscious, no-nonsense manner of many educated Indians, the entrepreneur quizzed me on which university I had gone to (Cambridge) and the subject I had studied (physics), before triumphantly declaring that I had been â€Å"born in the wrong country†. (p. 1, line 8-11) Language is formal, there is not used any kind of slang nor sarcasm or irony. There is much appeal to logos in the article because it is based on logic or reason and there are several facts. The article is argumentative for the reason that the reader becomes wiser and informed. The arguments which are used are objective and the choices of words are neutral. The purpose of writing the text could be that the Randeep Ramesh wants to influence the reader and express his own opinion. He generally informs the reader and makes his point clear.

Teaching the Life Skills in Special Education

Here is a list of life skills that students/children with developmental delays should be taught once they are able to learn them: Personal InformationName, address, telephone numbers, location of their paper identification, contact information. Sign InformationSigns in the community: Stop, men, women, no smoking, out of order, no loitering,exit, detour, pedestrian crossing, yield, no dogs etc. Important LabelsFlammable, poison, harmful, out of reach of children, high voltage. Knobs, dials, buttons, switches:TV, radio, stove, toasters, washer/dryer, microwave, taps, scales, handles etc. Application FormsSurname, occupation, signatures, initials, references. Finding InformationDictionaries, catalogues, internet, phonebooks, 911, location of important information etc. LabelsPrescription labels, direction labels, recipes, index, table of contents, shopping directories, calendars, important dates, holidays etc. Store TypesGrocery, laundry, hardware, drug store, restaurants, specialty, hairdresser/barber, recreation centres etc. LiteracyThank you cards, basic letters, invitation RSVPs, envelope addresses Basic LawsTraffic signs and signals, no smoking, speed limits, vandalism, noise bylaws, loitering etc. BankingAccount management, debit card use, deposits and withdrawals, writing cheques, understanding statements MoneyIdentification, change, values, coins, paper and equivalencies TimeTelling time, being on time, understanding the difference between analog and ditital, alarm clock settings, times for work, meals and sleep These are just some of the important life skills that students with developmental delays will need to be taught. Some individuals will be capable of learning more of the basic skills than others. However, these basic life skills are an important part of their curriculum. Many activities can be done to help support the learning of these activites - it may take some creativity and hands on experiences.