Understanding Sexual Dimorphism

Understanding Sexual Dimorphism Sexual dimorphism is the difference in morphology between male and female members of the same species. Sexual dimorphism includes differences in size, coloration, or body structure between the sexes. For example, the male northern cardinal has a bright red plumage while the female has a duller plumage. Male lions  have a mane, female lions do not. Examples of Sexual Dimorphism Male elk (Cervus canadensis) grow antlers, while female elk do not have antlers.Male elephant seals (Mirounga sp.) develop an elongated snout and fleshy nose that they inflate as a sign of aggression when competing with other males during the mating season.Male birds of paradise (Paradisaeidae) are noted for their elaborate plumage and complex mating dances. Females are far less ornate. In most cases, when size differences exist between the male and female of a species, it is the male that is the larger of the two sexes. But in a few species, such as birds of prey and owls, the female is the larger of the sexes and such a size difference is referred to as reverse sexual dimorphism. One rather extreme case of reverse sexual dimorphism exists in a species of deepwater anglerfish called the triplewart seadevils (Cryptopsaras couesii). The female triplewart seadevil grows much larger than the male and develops the characteristic illicium that serves as a lure to prey. The male, about one-tenth the size of the female, attaches itself to the female as a parasite. Resources and Further Reading Folkens P. 2002. National Audubon Society Guide to Marine Mammals of the World. New York: Alfred A. Knopff.

George essays

George essays George Washington is best known as the Father of our Country. He cared for this country much like a parent would care for a child. During his presidency, he solved many noteworthy problems. His achievements led to a democratic, wonderful country we like to call The United States of America. Although hes not thought of as glamorous, George Washington is looked with the utmost respect and awe by all countries of the world. George Washington was born in Westmoreland County, Virginia on February 22, 2. ` Virginia was alarmed when a French expedition from Canada established on the headwaters of the Ohio River. Conflict over this area eventually into the French and Indian War, in which Washington played a major military role that established his reputation as a commander. In the fall of 1758 the French were defeated. In 1759 he married Martha Dandridge Custis, a young widow. Washington matured into a solid member of Virginia society. From 1759 to 1774 he served in the House of Burgesses. By 1774 had become a key supporter of the colonial cause. That same year he was elected to the First Continental Congress. In 1775 the Second Continental Congress elected Washington commander in chief of its army. In July Washington arrived in Massachusetts, where the battles at Lexington and Concord had been fought. The British pulled back most of their troops to in New York City, leaving scattered garrisons of German mercenaries in New ...

The Use of eBooks in the Educational Process at Schools and Colleges Research Paper

The Use of eBooks in the Educational Process at Schools and Colleges - Research Paper Example This technological transition has seen the emergence of the E-books which is a system in which an entire book is stored in a soft copy. They have to be stored in a computer and can be accessed at any time through the internet. The devices used to access the e-books are referred to as the e-readers. The use of e-books has earned global fame since it is accessible through the internet which has transformed the world into a global village. The emergence of this form of technology has been so rampant in the market to the extent that those companies dealing in books and ignored its usage have found it hard to survive in the markets. (Matthews 54) Borders Books in the United States of America is a perfect example of the importance of the use of e-books. The company went out of business because electronically sensitive companies emerged. These companies, Amazon and E bay forced them out of business. Amazon’s operations are centered on the Linux operating system. This has enabled the corporation handle the wide customer base. Another advantage of technology in business is that it has ensured the security of customers and the company since information is well secured. E-commerce strategies used by modern companies has enabled customers transact regionally, internationally or even globally. The usage of e-books has even grown further across the globe thanks to its ‘question and answer sections’ which users find very sufficient as they are able extract the information they need without searching for too long. Most e-books are designed in a PDF format since it is the most common format across the globe. This drive is aimed at ensuring that as many people as possible across the world are able to access the e-books. The future of e-books look promising due to the overwhelming reception it has received globally. The existence of search engines such as the one availed by Google also contribute significantly to the growth of e-books as they enable people to find the e-books of their choice from the internet with much ease. Competition among the firms dealing in e-books also ensures its continuity as new products keep emerging by the day. E-books can be read from the internet or be downloaded to be read later. The use of e-books has also been boosted a great deal through their endorsement by prominent personnel in the society. These persons are known to greatly influence the tastes and preferences of many in a society. For instance, Oprah Winfrey once claimed that the emergence of the e-books was her most favorite form of invention as it enabled her to become a good reader which she said she was not before. This virtually convinced people that this was a great form of invention and many gave it a try. (Swedberg 112) The emergence of every form of invention has always come with its merits and demerits and e-books is not an exception. However good or productive an invention may be, it always comes with its negative side effects even if it is of the slightest magnitude. E-books are however observed to bring with them more advantages than disadvantages. Some of the advantages of e-books include: e-books come in various forms such: written form, image form, audio form and video. This gives e-books an edge over the hard copy books as those users who do not fancy reading can opt to use the video or audio forms of e-books. This way it also makes it possible for the