EvolutionIn biology, evolution is the change in heritable characteristics of biological populations over successive generations. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation.
Maximum parsimony (phylogenetics)In phylogenetics, maximum parsimony is an optimality criterion under which the phylogenetic tree that minimizes the total number of character-state changes (or minimizes the cost of differentially weighted character-state changes). Under the maximum-parsimony criterion, the optimal tree will minimize the amount of homoplasy (i.e., convergent evolution, parallel evolution, and evolutionary reversals). In other words, under this criterion, the shortest possible tree that explains the data is considered best.
Y-chromosomal AdamIn human genetics, the Y-chromosomal most recent common ancestor (Y-MRCA, informally known as Y-chromosomal Adam) is the patrilineal most recent common ancestor (MRCA) from whom all currently living humans are descended. He is the most recent male from whom all living humans are descended through an unbroken line of their male ancestors. The term Y-MRCA reflects the fact that the Y chromosomes of all currently living human males are directly derived from the Y chromosome of this remote ancestor.
HomininaeAutomatic taxobox | fossil_range = | image = Secretary_Leonard_Carmichael.jpg | image_caption = Three hominines – an adult human (Leonard Carmichael) holding a young gorilla and a young chimpanzee. | taxon = Homininae | authority = Gray, 1825 | type_species = Homo sapiens | type_species_authority = Linnaeus, 1758 | subdivision_ranks = Tribes | subdivision = * †Dryopithecini Gorillini Hominini Homininae (hɒmᵻˈnaɪniː), also called "African hominids" or "African apes", is a subfamily of Hominidae.
HomininiThe Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera Homo (humans) and Pan (chimpanzees and bonobos) and in standard usage excludes the genus Gorilla (gorillas). The term was originally introduced by Camille Arambourg (1948). Arambourg combined the categories of Hominina and Simiina due to Gray (1825) into his new subtribe. Traditionally, chimpanzees, gorillas and orangutans were grouped together as pongids.
Mexican NavyThe Mexican Navy is one of the two independent armed forces of Mexico. The actual naval forces are called the Armada de México. The Secretaría de Marina (SEMAR) (English: Naval Secretariat) includes both the Armada itself and the attached ministerial and civil service. The commander of the Navy is the Secretary of the Navy, who is both a cabinet minister and a career naval officer. The Mexican Navy's stated mission is "to use the naval force of the federation for external defense, and to help with internal order".
GibbonGibbons (ˈɡɪbənz) are apes in the family Hylobatidae (ˌhaɪləˈbætᵻdiː). The family historically contained one genus, but now is split into four extant genera and 20 species. Gibbons live in subtropical and tropical rainforests from eastern Bangladesh to Northeast India to southern China and Indonesia (including the islands of Sumatra, Borneo and Java). Also called the lesser apes, gibbons differ from great apes (bonobos, chimpanzees, gorillas, orangutans and humans) in being smaller, exhibiting low sexual dimorphism, and not making nests.
Hemolytic anemiaHemolytic anemia or haemolytic anaemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells (RBCs), either in the blood vessels (intravascular hemolysis) or elsewhere in the human body (extravascular). This most commonly occurs within the spleen, but also can occur in the reticuloendothelial system or mechanically (prosthetic valve damage). Hemolytic anemia accounts for 5% of all existing anemias. It has numerous possible consequences, ranging from general symptoms to life-threatening systemic effects.
MexicoMexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers 1,972,550 km2 (761,610 sq mi), making it the world's 13th-largest country by area; with a population of over 126 million, it is the 10th-most-populous country and has the most Spanish speakers.
Hereditary spherocytosisHereditary spherocytosis (HS) is a congenital hemolytic disorder, wherein a genetic mutation coding for a structural membrane protein phenotype leads to a spherical shaping of erythrocytic cellular morphology. As erythrocytes are sphere-shaped (spherocytosis), rather than the normal biconcave disk-shaped, their morphology interferes with these cells' abilities to be flexible during circulation throughout the entirety of the body - arteries, arterioles, capillaries, venules, veins, and organs.