{"id":7249,"date":"2019-05-22T15:54:49","date_gmt":"2019-05-22T15:54:49","guid":{"rendered":"http:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/allometry\/"},"modified":"2019-05-22T15:54:49","modified_gmt":"2019-05-22T15:54:49","slug":"allometry","status":"publish","type":"post","link":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/allometry\/","title":{"rendered":"Allometry"},"content":{"rendered":"<p>In biology, the study of relationships between size and shape. &nbsp;During mammalian growth, different parts of the body grow at different rates, but in a proportional manner so that body shape is noticeably altered during this period without distorting a recognizable species-characteristic form. &nbsp;There are two forms of allometry: negative allometry in which one body part grows slowly than other (e.g., head grows more slowly than torso), and positive allometry (e.g., legs grow more quickly than torso). &nbsp;See figure below for a further example. &nbsp;Over developmental time, allometric changes also take place in the face such that a full-blown &#8216;baby face&#8217;, as described by <a href=\"http:\/\/www.amphilsoc.org\/sites\/default\/files\/Lorenz.pdf\" data-editable-link=\"http:\/\/www.amphilsoc.org\/sites\/default\/files\/Lorenz.pdf&amp;target=_self\" target=\"_self\" rel=\"noopener noreferrer\">Konrad Z. Lorenz<\/a> (1903-1989), in terms of it being an innate releasing mechanism (IRM), is evident in humans at about 2 to 3 months after birth (see other figure below). &nbsp;According to Lorenz, it serves as an IRM that triggers protective feelings in older children and adults. &nbsp;Some preterm infants may lack a &#8216;baby face&#8217;, contributing to their risk for abuse. &nbsp;It is also used in evolutionary biology to relate changes in body and brain size. The basic allometric formula is expressed as a simple power function<\/p>\n<\/p>\n<p><img decoding=\"async\" src=\"..\/wp-content\/uploads\/2019\/05\/Screen-shot-2012-05-28-at-11.29.19.png\" \/><\/div>\n<\/div>\n<p>where y and x are the sizes of respective organs and body parts and b and k are constants. &nbsp;The formula can be given as: log y = log b+k.log x. &nbsp;When y is plotted against x on semi-log paper, estimates can be made of the constants b and k, where k is the slope of the allometric line and b the intercept of this line with the ordinate.<\/p>\n<p class=\"\" style=\"text-align: center;\">\n<p><img decoding=\"async\" src=\"..\/wp-content\/uploads\/2019\/05\/image009.png\" \/><\/div>\n<\/div>\n<p class=\"\" style=\"text-align: center;\">Allometry in the chimpanzee (<span class=\"\" style=\"font-style: italic;\">Pan troglodytes<\/span>): with growth, body size increases as brain size decreases (negative allometry), and body size increases as jaw size increases (positive allometry)<\/p>\n<\/p>\n<p><img decoding=\"async\" src=\"..\/wp-content\/uploads\/2019\/05\/image010.jpg\" \/><\/div>\n<\/div>\n<p class=\"\" style=\"text-align: center;\">Allometric changes in the growth of the face that result in the loss of a &#8216;baby face<\/p>\n<p>See <a href=\"growth\">Growth<\/a>, <a href=\"innate_releasing_mechanism_-irm-\">Innate releasing mechanism (IRM)<\/a>, <a href=\"preterm_infant\">Preterm infant<\/a>, Quantitative and qualitative change<\/p>\n<p><\/body><\/html><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In biology, the study of relationships between size and shape. &nbsp;During mammalian growth, different parts of the body grow at different rates, but in a proportional manner so that body shape is noticeably altered during this period without distorting a recognizable species-characteristic form. &nbsp;There are two forms of allometry: negative allometry in which one body &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/allometry\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Allometry&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[2],"class_list":["post-7249","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-glossary","entry"],"_links":{"self":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/7249","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/comments?post=7249"}],"version-history":[{"count":0,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/7249\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/media?parent=7249"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/categories?post=7249"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/tags?post=7249"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}