{"id":610,"date":"2024-04-14T21:46:41","date_gmt":"2024-04-14T21:46:41","guid":{"rendered":"https:\/\/workhouse.sweetdishy.com\/?p=610"},"modified":"2024-04-14T21:46:41","modified_gmt":"2024-04-14T21:46:41","slug":"historical-background","status":"publish","type":"post","link":"https:\/\/workhouse.sweetdishy.com\/index.php\/2024\/04\/14\/historical-background\/","title":{"rendered":"Historical background"},"content":{"rendered":"\n<p><strong>Ancient theories of pangenesis and blood in heredity<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Although scientific evidence for patterns of genetic inheritance did not appear until Mendel\u2019s work, history shows that humankind must have been interested in heredity long before the dawn of civilization. Curiosity must first have been based on\u00a0human\u00a0family resemblances, such as similarity in body structure, voice, gait, and gestures. Such notions were instrumental in the establishment of family and royal\u00a0dynasties. Early\u00a0nomadic tribes\u00a0were interested in the qualities of the animals that they herded and domesticated and, undoubtedly, bred selectively. The first human settlements that practiced farming appear to have selected crop plants with favourable qualities. Ancient tomb paintings show racehorse breeding pedigrees containing clear depictions of the inheritance of several distinct physical traits in the horses. Despite this interest, the first recorded speculations on heredity did not exist until the time of the ancient Greeks; some aspects of their ideas are still considered relevant today.<\/li>\n\n\n\n<li>Hippocrates\u00a0(<em>c.<\/em>\u00a0460\u2013<em>c.<\/em>\u00a0375\u00a0BCE), known as the father of medicine, believed in the inheritance of acquired characteristics, and, to account for this, he devised the\u00a0hypothesis\u00a0known as\u00a0pangenesis. He postulated that all organs of the body of a parent gave off invisible \u201cseeds,\u201d which were like miniaturized building components and were transmitted during\u00a0sexual intercourse, reassembling themselves in the mother\u2019s womb to form a baby.<\/li>\n<\/ul>\n\n\n\n<p><strong>Preformation\u00a0and natural selection<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>In the two millennia between the lives of\u00a0Aristotle\u00a0and\u00a0Mendel, few new ideas were recorded on the nature of\u00a0heredity. In the 17th and 18th centuries the idea of preformation was introduced. Scientists using the newly developed\u00a0microscopes imagined that they could see miniature\u00a0replicas\u00a0of human beings inside sperm heads. French biologist\u00a0Jean-Baptiste Lamarck\u00a0invoked the idea of \u201cthe inheritance of acquired characters,\u201d not as an explanation for heredity but as a model for\u00a0evolution. He lived at a time when the fixity of species was taken for granted, yet he maintained that this fixity was only found in a constant environment. He enunciated the\u00a0law of use and disuse, which states that when certain organs become specially developed as a result of some environmental need, then that state of development is hereditary and can be passed on to progeny. He believed that in this way, over many generations,\u00a0giraffes could arise from deerlike animals that had to keep stretching their necks to reach high leaves on trees.<\/li>\n\n\n\n<li>British naturalist\u00a0Alfred Russel Wallace\u00a0originally\u00a0postulated\u00a0the theory of evolution by\u00a0natural selection. However,\u00a0Charles Darwin\u2019s observations during his circumnavigation of the globe aboard the HMS\u00a0<em>Beagle<\/em>\u00a0(1831\u201336) provided evidence for natural selection and his suggestion that humans and animals shared a common ancestry. Many scientists at the time believed in a hereditary mechanism that was a version of the ancient Greek idea of pangenesis, and Darwin\u2019s ideas did not appear to fit with the theory of heredity that sprang from the experiments of Mendel.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Ancient theories of pangenesis and blood in heredity Preformation\u00a0and natural selection<\/p>\n","protected":false},"author":1,"featured_media":604,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-610","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"jetpack_featured_media_url":"https:\/\/workhouse.sweetdishy.com\/wp-content\/uploads\/2024\/04\/dna-1.png","_links":{"self":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/610","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/comments?post=610"}],"version-history":[{"count":1,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/610\/revisions"}],"predecessor-version":[{"id":611,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/610\/revisions\/611"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media\/604"}],"wp:attachment":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media?parent=610"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/categories?post=610"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/tags?post=610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}