Line 7: |
Line 7: |
| | | |
| ==Description== | | ==Description== |
− | '''''Ascending and Descending''''' is a [[Prints|lithograph]] print by the Dutch artist [http://en.wikipedia.org/wiki/M.C.Escher M.C. Escher] which was first printed in March 1960. | + | In [https://en.wikipedia.org/wiki/Evolutionary_biology evolutionary biology], a group of [[organisms]] have common '''descent''' if they have a common [[ancestor]]. "There is strong [[quantitative]] [[support]], by a [[formal]] test" for the [[theory]] that all living [[organisms]] on [[Earth]] are descended from a common ancestor. |
| | | |
− | The [[original]] [[print]] measures 14" x 11 1/4”. The lithograph depicts a large building roofed by a never-ending staircase. Two lines of identically dressed men appear on the staircase, one line ascending whilst the other descends. Two figures sit apart from the people on the [[eternal|endless]] staircase: one in a secluded courtyard, the other on a lower set of stairs. While most two-[[dimensional]] artists use [[relative]] proportions to [[create]] an [[illusion]] of depth, Escher here and elsewhere uses conflicting proportions to create the visual [[paradox]].
| + | [https://en.wikipedia.org/wiki/Charles_Darwin Charles Darwin] proposed the [[theory]] of universal common descent through an [[evolutionary]] [[process]] in [https://en.wikipedia.org/wiki/On_the_Origin_of_Species ''On the Origin of Species''], saying, "There is a grandeur in this view of life, with its several [[powers]], having been originally breathed into a few forms or into one". |
| | | |
− | ''Ascending and Descending'' was [[influence]]d by, and is an artistic implementation of, the [http://en.wikipedia.org/wiki/Lionel_Penrose Penrose stairs], an impossible object; Lionel Penrose had first published his concept in the February, 1958 issue of the ''British Journal of Psychology''. Escher developed the theme further in his [[print]] ''Waterfall'', which appeared in 1961.
| + | The last [[universal]] [[ancestor]] (LUA) (or last universal common ancestor, LUCA), that is, the most recent common ancestor of all currently living [[organisms]], is believed to have appeared about 3.9 billion years ago. |
| | | |
− | ==References in popular culture==
| + | In [https://en.wikipedia.org/wiki/The_Ancestor%27s_Tale ''The Ancestor's Tale''], [https://en.wikipedia.org/wiki/Richard_Dawkins Richard Dawkins] coined the word concestor, as a substitute for common ancestor or most recent common ancestor. This new [[word]] is very gradually entering [[scientific]] parlance. |
− | * [http://www.voidgamers.com/channel/HirstArts/HADD7/b.356.r.386.html Ascending and Descending] A wonderful 3D forced perspective model was build as part of a kit building contest
| + | ==Descent and the family== |
| + | Descent, like [[family]] systems, is one of the major [[concepts]] of [[anthropology]]. [[Cultures]] worldwide [[possess]] a wide range of systems of tracing kinship and descent. Anthropologists break these down into simple [[concepts]] about what is [[thought]] to be common among many different cultures. |
| + | *Descent groups |
| + | A ''descent group'' is a [[social]] [[group]] whose members claim [[common]] [[ancestry]]. A unilineal [[society]] is one in which the descent of an [[individual]] is reckoned either from the [[mother]]'s or the [[father]]'s line of descent. With matrilineal descent individuals belong to their mother's descent group. ''Matrilineal descent'' includes the mother's brother, who in some societies may pass along [[inheritance]] to the sister's children or [[succession]] to a sister's son. With ''patrilineal descent'', [[individuals]] belong to their father's descent group. Societies with the [https://en.wikipedia.org/wiki/Iroquois Iroquois] kinship system, are typically uniliineal, while the Iroquois proper are specifically matrilineal. |
| | | |
− | ==Sources==
| + | In a [[society]] which reckons descent bilaterally (bilineal), descent is reckoned through both father and mother, without unilineal descent groups. Societies with the [https://en.wikipedia.org/wiki/Eskimo Eskimo] kinship system, like the Eskimo proper, are typically bilateral. The egocentrid kindred group is also typical of bilateral societies. |
− | *Locher, J.L. (2000). ''The Magic of M. C. Escher''. ISBN 0-8109-6720-0.
| |
| | | |
| + | Some [[societies]] reckon descent patrilineally for some [[purposes]], and matrilineally for others. This arrangement is sometimes called double descent. For instance, certain [[property]] and titles may be inherited through the [[male]] line, and others through the [[female]] line. |
| + | |
| + | Societies can also consider descent to be ambilineal (such as Hawaiian kinship) where offspring determine their lineage through the matrilineal line or the patrilineal line. |
| + | ==See also== |
| + | *'''''[[Descending Sons]]''''' |
| + | [[Category: Biology]] |
| + | [[Category: Anthropology]] |
| [[Category: General Reference]] | | [[Category: General Reference]] |