Bacterial conjugationBacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. This takes place through a pilus. It is a parasexual mode of reproduction in bacteria. It is a mechanism of horizontal gene transfer as are transformation and transduction although these two other mechanisms do not involve cell-to-cell contact. Classical E. coli bacterial conjugation is often regarded as the bacterial equivalent of sexual reproduction or mating since it involves the exchange of genetic material.
Peripatric speciationPeripatric speciation is a mode of speciation in which a new species is formed from an isolated peripheral population. Since peripatric speciation resembles allopatric speciation, in that populations are isolated and prevented from exchanging genes, it can often be difficult to distinguish between them. Nevertheless, the primary characteristic of peripatric speciation proposes that one of the populations is much smaller than the other.
Multiregional origin of modern humansThe multiregional hypothesis, multiregional evolution (MRE), or polycentric hypothesis, is a scientific model that provides an alternative explanation to the more widely accepted "Out of Africa" model of monogenesis for the pattern of human evolution. Multiregional evolution holds that the human species first arose around two million years ago and subsequent human evolution has been within a single, continuous human species. This species encompasses all archaic human forms such as H.
Humid subtropical climateA humid subtropical climate is a temperate climate type characterized by hot and humid summers, and cool to mild winters. These climates normally lie on the southeast side of all continents (except Antarctica), generally between latitudes 25° and 40° and are located poleward from adjacent tropical climates. It is also known as warm temperate climate in some climate classifications. Under the Köppen climate classification, Cfa and Cwa climates are either described as humid subtropical climates or warm temperate climates.
Latitudinal gradients in species diversitySpecies richness, or biodiversity, increases from the poles to the tropics for a wide variety of terrestrial and marine organisms, often referred to as the latitudinal diversity gradient. The latitudinal diversity gradient is one of the most widely recognized patterns in ecology. It has been observed to varying degrees in Earth's past. A parallel trend has been found with elevation (elevational diversity gradient), though this is less well-studied.
Medieval universityA medieval university was a corporation organized during the Middle Ages for the purposes of higher education. The first Western European institutions generally considered to be universities were established in present-day Italy, including the Kingdoms of Sicily and Naples, and the Kingdoms of England, France, Spain, Portugal, and Scotland between the 11th and 15th centuries for the study of the arts and the higher disciplines of theology, law, and medicine.
Ancient MacedoniansThe Macedonians (Μακεδόνες, Makedónes) were an ancient tribe that lived on the alluvial plain around the rivers Haliacmon and lower Axios in the northeastern part of mainland Greece. Essentially an ancient Greek people, they gradually expanded from their homeland along the Haliacmon valley on the northern edge of the Greek world, absorbing or driving out neighbouring non-Greek tribes, primarily Thracian and Illyrian.
Middle AgesIn the history of Europe, the Middle Ages or medieval period (also spelled mediæval or mediaeval) lasted approximately from the late 5th to the late 15th centuries, aligning with the post-classical period of global history. It began with the fall of the Western Roman Empire in 476 AD and ended with the fall of Constantinople in 1453 AD before transitioning into the Renaissance and then the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: antiquity, medieval, and modern.
Koch's postulatesKoch's postulates (kɒx ) are four criteria designed to establish a causal relationship between a microbe and a disease. The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884, based on earlier concepts described by Jakob Henle, and the statements were refined and published by Koch in 1890. Koch applied the postulates to describe the etiology of cholera and tuberculosis, both of which are now ascribed to bacteria. The postulates have been controversially generalized to other diseases.
Ancient EgyptAncient Egypt was a civilization in Northeast Africa situated in the Nile Valley. Ancient Egyptian civilization followed prehistoric Egypt and coalesced around 3100 BC (according to conventional Egyptian chronology) with the political unification of Upper and Lower Egypt under Menes (often identified with Narmer). The history of ancient Egypt occurred as a series of stable kingdoms, separated by periods of relative instability known as Intermediate Periods: the Old Kingdom of the Early Bronze Age, the Middle Kingdom of the Middle Bronze Age and the New Kingdom of the Late Bronze Age.
