Forget the Word Can't

The development of external combustion engines is detailed as part of the history of the car but often treated separately from the development of true cars. A variety of steam-powered road vehicles were used during the first part of the 19th century, including steam cars, steam buses, phaetons, and steam rollers. In the UK, sentiment against them led to the Locomotive Acts of 1865.

The medieval music era (476 to 1400), which took place during the Middle Ages, started with the introduction of monophonic (single melodic line) chanting into Roman Catholic Church services. Musical notation was used since Ancient times in Greek culture, but in the Middle Ages, notation was first introduced by the Catholic church so that the chant melodies could be written down, to facilitate the use of the same melodies for religious music across the entire Catholic empire. The only European Medieval repertory that has been found in written form from before 800 is the monophonic liturgical plainsong chant of the Roman Catholic Church, the central tradition of which was called Gregorian chant. Alongside these traditions of sacred and church music there existed a vibrant tradition of secular song (non-religious songs). Examples of composers from this period are Léonin, Pérotin, Guillaume de Machaut, and Walther von der Vogelweide.

Renaissance music (c. 1400 to 1600) was more focused on secular (non-religious) themes, such as courtly love. Around 1450, the printing press was invented, which made printed sheet music much less expensive and easier to mass-produce (prior to the invention of the printing press, all notated music was hand-copied). The increased availability of sheet music helped to spread musical styles more quickly and across a larger area. Musicians and singers often worked for the church, courts and towns. Church choirs grew in size, and the church remained an important patron of music. By the middle of the 15th century, composers wrote richly polyphonic sacred music, in which different melody lines were interwoven simultaneously. Prominent composers from this era include Guillaume Dufay, Giovanni Pierluigi da Palestrina, Thomas Morley, and Orlande de Lassus. As musical activity shifted from the church to the aristocratic courts, kings, queens and princes competed for the finest composers. Many leading important composers came from the Netherlands, Belgium, and northern France. They are called the Franco-Flemish composers. They held important positions throughout Europe, especially in Italy. Other countries with vibrant musical activity included Germany, England, and Spain.

Animals are monophyletic, meaning they are derived from a common ancestor. Animals are sister to the Choanoflagellata, with which they form the Choanozoa.[106] The most basal animals, the Porifera, Ctenophora, Cnidaria, and Placozoa, have body plans that lack bilateral symmetry. Their relationships are still disputed; the sister group to all other animals could be the Porifera or the Ctenophora,[107] both of which lack hox genes, important in body plan development.[108]

These genes are found in the Placozoa[109][110] and the higher animals, the Bilateria.[111][112] 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago in the Precambrian. 25 of these are novel core gene groups, found only in animals; of those, 8 are for essential components of the Wnt and TGF-beta signalling pathways which may have enabled animals to become multicellular by providing a pattern for the body's system of axes (in three dimensions), and another 7 are for transcription factors including homeodomain proteins involved in the control of development.[113][114]

The phylogenetic tree indicates approximately how many millions of years ago (mya) the lineages split.