A Profile of Byzantine Emperor Alexios Komnenos

A Profile of Byzantine Emperor Alexios Komnenos Alexius Comnenus, also known as  Alexios Komnenos, is perhaps best known for seizing the throne from Nicephorus III and founding the Comnenus dynasty. As emperor, Alexius stabilized the government of the empire. He was also Emperor during the First Crusade. Alexius is the subject of a biography by his learned daughter, Anna Comnena. Occupations: EmperorCrusade WitnessMilitary Leader Places of Residence and Influence: Byzantium (Eastern Rome) Important Dates: Born: 1048Crowned: April 4, 1081Died: Aug. 15, 1118 About Alexius Comnenus Alexius was the third son of John Comnenus and a nephew of Emperor Isaac I. From 1068 to 1081, during the reigns of Romanus IV, Michael VII, and Nicephorus III, he served in the military; then, with the help of his brother Isaac, his mother Anna Dalassena, and his powerful in-laws the Ducas family, he seized the throne from Nicephorus III. For more than half a century the empire had suffered from ineffective or short-lived leaders. Alexius was able to drive the Italian Normans from western Greece, defeat Turkic nomads whod been invading the Balkans, and halt the encroachment of the Seljuq Turks. He also negotiated agreements with Sulayman ibn Qutalmà ¯sh of Konya and other Muslim leaders on the empires eastern border. At home he strengthened the central authority and built up military and naval forces, thus increasing imperial strength in portions of Anatolia (Turkey) and the Mediterranean. These actions helped stabilize Byzantium, but other policies would cause difficulties for his reign. Alexius made concessions to powerful landed magnates which would serve to weaken the authority of himself and future emperors. Although he maintained the traditional imperial role of protecting the Eastern Orthodox Church and repressed heresy, he also seized funds from the Church when necessary, and would be called to account for these actions by the ecclesiastical authorities. Alexius is well known for appealing to Pope Urban II for help in driving the Turks from Byzantine territory. The resulting influx of Crusaders would plague him for years to come.

Hexapods Are a Diverse Group of Six-Legged Arthropods

Hexapods Are a Diverse Group of Six-Legged Arthropods Hexapods are a group of arthropods that include more than one million described, species, most of which are insects, but a handful of which belong to the lesser-known group Entognatha. In terms of the sheer number of species, no other family of animals comes close to the hexapods; these six-legged arthropods are, in fact, over twice as diverse as all other vertebrate and invertebrate animals combined. Most hexapods are terrestrial animals, but there are some exceptions to this rule. Some species live in aquatic freshwater habitats such as lakes, wetlands, and rivers, while others inhabit coastal marine waters. Hexapods Avoid Sub-Tidal Marine Areas The only habitats that hexapods avoid are sub-tidal marine areas, such as oceans and shallow seas. The success of hexapods in colonizing land can be attributed to their body plan (especially the strong cuticles covering their bodies that provide protection from predators, infection and water loss), as well as their flying skills. Another successful attribute of hexapods is their  holometabolous development, a mouthful of a term which means that juvenile and adult hexapods of the same species are very different in their ecological requirements, immature hexapods using different resources (including food sources and habitat features) than the adults of the same species. Hexapods Are Vital But Also Pose Many Threats Hexapods are vital to the communities in which they live; for example, early two-thirds of all flowering plant species rely on hexapods for pollination. Yet hexapods also pose many threats. These small arthropods can inflict vast crop damage and are known to spread numerous debilitating and fatal diseases in humans and other animals. The body of a hexapod is made up of three sections, a head, a thorax, and an abdomen. The head has a pair of compound  eyes, a pair of antennae, and numerous mouthparts (such as mandibles, labrum, maxilla, and labium). The Three Segments of Thorax The thorax consists of three segments, the prothorax, the mesothorax, and the metathorax. Each segment of the thorax has a pair of legs, making for six legs in all (the forelegs, the middle legs, and the hind legs). Most adult insects also possess two pairs of wings; the forewings are located on the mesothorax and the hind-wings are attached to the metathorax. Wingless Hexapods Although most adult hexapods have wings, some species are wingless throughout their life cycles or lose their wings after a certain period before adulthood. For example, parasitic insect orders such as lice and fleas no longer have wings (although their ancestors of millions of years ago did have wings). Other groups, such as the Entognatha and Zygentoma, are more primitive than classic insects; not even the ancestors of these animals had wings. Many hexapods have evolved alongside plants in a process known as coevolution. Pollination is one example of a coevolutionary adaptation between plants and pollinators in which both parties benefit. Classification Hexapods are classified within the following taxonomic hierarchy: Animals Invertebrates Arthropods Hexapods Hexapods are divided into the following basic groups: Insects (Insecta) - There are more than one million species of insects that have been identified, and scientists estimate that there may be many millions more species yet to be named. Insects have three pairs of legs, two pairs of wings and compound eyes.Springtails and their relatives (Entognatha) - The mouthparts of springtails, such as the two-pronged bristletails and the proturans (or coneheads), can be retracted within their heads. All entognaths lack wings. Edited on February 10, 2017, by Bob Strauss