Lagomorpha Include Hares, Rabbits, and Pikas

Hares, pikas, and rabbits (Lagomorpha) are small terrestrial mammals that include cottontails, jackrabbits, pikas, hares, and rabbits. The group is also commonly referred to as lagomorphs. There are about 80 species of lagomorphs divided into two subgroups, the pikas and the hares and rabbits. Lagomorphs are not as diverse as many other mammal groups, but they are widespread. They inhabit every continent except Antarctica and are absent from only a few places around the globe such as parts of South America, Greenland, Indonesia, and Madagascar. Although not native to Australia, lagomorphs have been introduced there by humans and have since successfully colonized many parts of the continent. Lagomorphs generally have a short tail, large ears, wide-set eyes and narrow, slit-like nostrils that they can scrunch tightly closed. The two subgroups of lagomorphs differ considerably in their general appearance. Hares and rabbits are larger and have long hind legs, a short bushy tail, and long ears. Pikas, on the other hand, in contrast, are smaller than hares and rabbits and more rotund. They have round bodies, short legs, and a tiny, barely-visible tail. Their ears are prominent but are rounded and not as conspicuous as those of hares and rabbits. Lagomorphs often form the foundation of many predator-prey relationships in the ecosystems they inhabit. As important prey animals, lagomorphs are hunted by animals such as carnivores, owls, and birds of prey. Many of their physical characteristics and specializations have evolved as a means of helping them escape predation. For example, their large ears enable them to hear approaching danger better; the position of their eyes enables them to have a near 360-degree range of vision; their long legs enable them to run quickly and out-maneuver predators. Lagomorphs are herbivores. They feed on grass, fruits, seeds, bark, roots, herbs, and other plant material. Since the plants they eat are difficult to digest, they expel a wet fecal matter and eat it to ensure that the material passes through their digestive system twice. This enables them to extract as much nutrition as possible from their food. Lagomorphs inhabit most terrestrial habitats including semi-deserts, grasslands, woodlands, tropical forests, and arctic tundra. Their distribution is worldwide with the exception of Antarctica, southern South America, most islands, Australia, Madagascar, and the West Indies. Lagomorphs have been introduced by humans to many ranges in which they were not formerly found and often such introductions have led to widespread colonization. Evolution The earliest representative of the lagomorphs is thought to be Hsiuannania, a ground-dwelling herbivore that lived during the Paleocene in China. Hsiuannania is known from just a few fragments of teeth and jawbones. Despite the scant fossil record for early lagomorphs, what evidence there is indicates that the lagomorph clade originated somewhere in Asia. The earliest ancestor of rabbits and hares lived 55 million years ago in Mongolia. Pikas emerged about 50 million years ago during the Eocene. Pika evolution is difficult to resolve, as only seven species of pikas are represented in the fossil record. Classification The classification of lagomorphs is highly controversial. At one time, lagomorphs were considered to be rodents due to striking physical similarities between the two groups. But more recent molecular evidence has supported the notion that lagomorphs are no more related to rodents than they are to other mammal groups. For this reason, they are now ranked as an entirely separate group of mammals. Lagomorphs are classified within the following taxonomic hierarchy: Animals Chordates Vertebrates Tetrapods Amniotes Mammals Lagomorphs Lagomorphs are divided into the following taxonomic groups: Pikas (Ochotonidae) - There are about 30 species of pikas alive today. Members of this group include silver pikas, collard pikas, steppe pikas, Chinese red pikas, Himalayan pikas, and many other species. Pikas are notable for their short, rounded ears, lack of a tail, and round body.Hares and rabbits (Leporidae) -Â  There are about 50 species of hares and rabbits alive today. Members of this group include eastern cottontails, robust cottontails, European rabbits, antelope jackrabbits, snowshoe hares, Arctic hares, volcano rabbits, desert hares, Abyssinian hares, and many others.

The Digestive System and Digestive Process Essay

Essays on The Digestive System and Digestive Process Essay The paper "The Digestive System and Digestive Process" is a wonderful example of an essay on biology. Different types of foods come along with different nutrients such as vitamins, carbohydrates, fats, minerals, and proteins. These nutrients are often a source of energy and material to the body cells. The problem is that most of these nutrients cannot be used by the body for energy in the form in which they are eaten. Hence, before these nutrients are absorbed and carried to the body cells, they need to be broken out and changed into smaller, usable pieces. This is the work of the digestive system with the help of the digestive organs. The digestive process is a rigorous task carried out by the digestive organs working together in the digestive system (Hoffman, 53). Of concern is whether it is possible to live without one or more of the digestive organs.   Each and every digestive organ has its own distinctive role. For this reason, it is impossible to live without one or more digestive organisms. However, the small intestine does the most work of any digestive organ. This is the point where food is broken down by physical grinding as well as special proteins known as enzymes that work on food at the molecular level. In addition, the small intestine is where almost all of the useful nutrients are absorbed into the body. By this time, all that is left for the large intestines is waste in the form of undigested food. Other digestive organs such as the pancreas, liver, and gallbladder are not part of the twisted tube through which food travels but play important roles in the digestive system (Scott Fong, 16). Regardless of how minor a role a digestive organ contributes to the digestive system, failure to have one of the digestive organizations can lead to a digestive breakdown. Therefore, every digestive organ plays a detrimental role in digestion, and however minor it may appear, its pathology may lead to incomplete digestion.

Ishmael Essay Example For Students

Ishmael Essay Ishmael The Destruction ContinuesIshmaelThe Biblical depiction of Adam and Eves fall builds the foundation of Daniel Quinns novel, Ishmael. In this adventure of the spirit, a telepathic gorilla, Ishmael, uses the history of Biblical characters in order to explain his philosophy on saving the world. Attracting his final student, the narrator of the novel, with an advertisement Teacher seeks pupil. Must have an earnest desire to save the world. Apply in person, Ishmael counsels the narrator through a series of questions that force him to stretch his mind. Diving straight into Biblical allusions, Ishmael begins his lesson with the history of his evolution from Goliath (17) to Ishmael. He explains this evolution as a time of realization where he shifts from blindly accepting the infamous reputation of Goliath, an evil giant from the Bible, to the quiet, thoughtful being of Ishmael. After his brief history, Ishmael shifts his attention to the creation. A culture is a people enacting a story (41), and the story of the Garden of Eden opened up new thoughts on mans transformation from dependent to independent beings. When Adam and Eve began their lives on earth, they fully depended on the gods for all their necessities. Just like all of the other animals in the garden, they followed the philosophy of leavers and left the question of who should live and who should die up to the gods. However, the serpent, a member of the taker group tempted Eve with fruit from a tree that would give them the knowledge of life and death. Eve, which means life (179) in turn, tempted Adam with the fruit. Although pre-warned that eating this forbidden fruit would kill man, Adam fell into temptation and his desire for life. Through this action, his eyes were partially opened to the gods vision. However, this knowledge ultimately would lead to the fulfillment of the gods warnings that the worlds doom was assured (166). After mans realization, he placed himself in a category separate from the animals and beasts that continued to rely on the worlds situation rather than themselves. An allusion to the Biblical story of Adam and Eves descendents, Cain and Abel continued the progression of mans shift from leavers, to what they are now, takers. The taker philosophy that the world was made for man (61), epitomized the their obstinate attitude that the universe was meant to be conquered and exploited by humans. Cain, a member of the taker philosophy and an agriculturist felt mans fate was in his or her hands. He showed these beliefs through the harvesting and storing of food. Abel, a member of the leavers demonstrated his philosophy of leaving everything alone except for what was needed in his hunter gatherer lifestyle. Cain and Abel represented two cultures. When these two cultures clashed, the takers began watering their fields with the blood of . . . herders (173). Cain took Abels life because according to him, the world was made for human control. Humans could will life as well as death. Slowly, as the takers and their philosophies took over the planet, they reem phasized the worlds ultimate destruction. Through the passage of time, these Biblical stories, written by the leavers, have been accepted into the culture of the takers. These allusions enhance the consequences of the takers and their beliefs because of their philosophy that they are their own gods and the world belongs to man. This philosophy has caused destruction. Unfortunately, not many realize it, and the destruction continuesWords/ Pages : 587 / 24