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The Specie Circular is a United States presidential executive order issued by President Andrew Jackson on 11 July 1836 pursuant to the Coinage Act of 1834. It required payment for government land to be in gold and silver (specie). [1] It was repealed by a joint act of Congress on 21 May 1838. [2]
Edward Hitchcock's fold-out paleontological chart in his 1840 Elementary Geology. Although tree-like diagrams have long been used to organise knowledge, and although branching diagrams known as claves ("keys") were omnipresent in eighteenth-century natural history, it appears that the earliest tree diagram of natural order was the 1801 "Arbre botanique" (Botanical Tree) of the French ...
Hard money policies support a specie standard, usually gold or silver, typically implemented with representative money. In 1836, when President Andrew Jackson's veto of the recharter of the Second Bank of the United States took effect, he issued the Specie Circular, an executive order that all public lands had to be purchased with hard money.
Circular diagrams are often used in phylogenetics, especially for the graphical representation of phylogenetic relationships. Evolutionary trees often encompass numerous species that are conveniently shown on a circular tree, with images of the species shown on the periphery of a tree.
Social cycle theories are among the earliest social theories in sociology.Unlike the theory of social evolutionism, which views the evolution of society and human history as progressing in some new, unique direction(s), sociological cycle theory argues that events and stages of society and history generally repeat themselves in cycles.
The 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.
Species go extinct constantly as environments change, as organisms compete for environmental niches, and as genetic mutation leads to the rise of new species from older ones. At long irregular intervals, Earth's biosphere suffers a catastrophic die-off, a mass extinction , [ 9 ] often comprising an accumulation of smaller extinction events over ...
This tree diagram, used to show the divergence of species, is the only illustration in the Origin of Species. Darwin proposes sexual selection, driven by competition between males for mates, to explain sexually dimorphic features such as lion manes, deer antlers, peacock tails, bird songs, and the bright plumage of some male birds. [129]