ConjunctivitisConjunctivitis, also known as pink eye, is inflammation of the outermost layer of the white part of the eye and the inner surface of the eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness, or itchiness may occur. The affected eye may have increased tears or be "stuck shut" in the morning. Swelling of the white part of the eye may also occur. Itching is more common in cases due to allergies. Conjunctivitis can affect one or both eyes. The most common infectious causes are viral followed by bacterial.
Early human migrationsEarly human migrations are the earliest migrations and expansions of archaic and modern humans across continents. They are believed to have begun approximately 2 million years ago with the early expansions out of Africa by Homo erectus. This initial migration was followed by other archaic humans including H. heidelbergensis, which lived around 500,000 years ago and was the likely ancestor of Denisovans and Neanderthals as well as modern humans. Early hominids had likely crossed land bridges that have now sunk.
Timeline of human evolutionThe timeline of human evolution outlines the major events in the evolutionary lineage of the modern human species, Homo sapiens, throughout the history of life, beginning some 4 billion years ago down to recent evolution within H. sapiens during and since the Last Glacial Period. It includes brief explanations of the various taxonomic ranks in the human lineage. The timeline reflects the mainstream views in modern taxonomy, based on the principle of phylogenetic nomenclature; in cases of open questions with no clear consensus, the main competing possibilities are briefly outlined.
HomoHomo () is the genus that emerged from the genus Australopithecus and encompasses the extant species Homo sapiens (modern humans) and several extinct species classified as either ancestral to or closely related to modern humans, including Homo erectus and Homo neanderthalensis. The oldest member of the genus is Homo habilis, with records of just over 2 million years ago. Homo, together with the genus Paranthropus, is probably sister to Australopithecus africanus, which itself had split from the lineage of Pan, the chimpanzees.
Asymptomatic carrierAn asymptomatic carrier is a person or other organism that has become infected with a pathogen, but shows no signs or symptoms. Although unaffected by the pathogen, carriers can transmit it to others or develop symptoms in later stages of the disease. Asymptomatic carriers play a critical role in the transmission of common infectious diseases such as typhoid, HIV, C. difficile, influenzas, cholera, tuberculosis and COVID-19, although the last is often associated with "robust T-cell immunity" in more than a quarter of patients studied.
Atopic dermatitisAtopic dermatitis (AD), also known as atopic eczema, is a long-term type of inflammation of the skin (dermatitis). It results in itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which can thicken over time. AD may also simply be called eczema, a term that generally refers to a larger group of skin conditions. Atopic dermatitis affects about 20% of people at some point in their lives. It is more common in younger children. Females are slightly more affected than males.
