{"id":124048,"date":"2009-09-01T09:26:00","date_gmt":"2009-09-01T09:26:00","guid":{"rendered":"http:\/\/weblogs.madrimasd.org\/\/universo\/archive\/2009\/09\/01\/124048.aspx"},"modified":"2010-01-22T03:53:32","modified_gmt":"2010-01-22T02:53:32","slug":"silcretas-tecnologia-paleolitica-pirotecnologia-y-evolucion-de-la-conciencia-humana","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2009\/09\/01\/124048","title":{"rendered":"Silcretas, Tecnolog\u00eda Paleol\u00edtica, Pirotecnolog\u00eda y Evoluci\u00f3n de la Conciencia Humana"},"content":{"rendered":"<link rel=\"File-List\" href=\"file:\/\/\/C:%5CDOCUME%7E1%5CJuanjo%5CCONFIG%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml\">\n<style> <!--  \/* Font Definitions *\/  @font-face \t{font-family:\"Comic Sans MS\"; \tpanose-1:3 15 7 2 3 3 2 2 2 4; \tmso-font-charset:0; \tmso-generic-font-family:script; \tmso-font-pitch:variable; \tmso-font-signature:647 0 0 0 159 0;} @font-face \t{font-family:\"Bookman Old Style\"; \tpanose-1:2 5 6 4 5 5 5 2 2 4; \tmso-font-charset:0; \tmso-generic-font-family:roman; \tmso-font-pitch:variable; \tmso-font-signature:647 0 0 0 159 0;}  \/* Style Definitions *\/  p.MsoNormal, li.MsoNormal, div.MsoNormal \t{mso-style-parent:\"\"; \tmargin:0pt; \tmargin-bottom:.0001pt; \tmso-pagination:widow-orphan; \tfont-size:12.0pt; \tfont-family:\"Times New Roman\"; \tmso-fareast-font-family:\"Times New Roman\";} a:link, span.MsoHyperlink \t{color:#000099; \tmso-text-animation:none; \ttext-decoration:none; \ttext-underline:none; \ttext-decoration:none; \ttext-line-through:none;} a:visited, span.MsoHyperlinkFollowed \t{color:purple; \ttext-decoration:underline; \ttext-underline:single;} @page Section1 \t{size:612.0pt 792.0pt; \tmargin:72.0pt 90.0pt 72.0pt 90.0pt; \tmso-header-margin:36.0pt; \tmso-footer-margin:36.0pt; \tmso-paper-source:0;} div.Section1 \t{page:Section1;} --> <\/style>\n<p><!--  \/* Style Definitions *\/  table.MsoNormalTable \t{mso-style-name:\"Tabla normal\"; \tmso-tstyle-rowband-size:0; \tmso-tstyle-colband-size:0; \tmso-style-noshow:yes; \tmso-style-parent:\"\"; \tmso-padding-alt:0pt 5.4pt 0pt 5.4pt; \tmso-para-margin:0pt; \tmso-para-margin-bottom:.0001pt; \tmso-pagination:widow-orphan; \tfont-size:10.0pt; \tfont-family:\"Times New Roman\";} -->  <\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Bookman Old Style&quot;;\">Diversos estudios recientes van retrotrayendo la evoluci\u00f3n cultural y humana hacia tiempos cada vez m\u00e1s remotos. Es habitual, en la literatura reciente, que se asocien las tecnolog\u00edas menos rudimentarias al Neol\u00edtico o a \u00e9pocas anteriores, aunque no muy distantes. Sin embargo, durante los \u00faltimos meses, parecen acumularse evidencias de que ya en el paleol\u00edtico remoto el ser humano atesoraba una <a href=\"http:\/\/www.nature.com\/news\/2008\/081030\/full\/news.2008.1196.html\">tecnolog\u00eda hasta ahora insospechada<\/a>, as\u00ed como un desarrollo cognitivo individual que permiti\u00f3 ir construyendo redes culturales que fomentaban el comercio y la cooperaci\u00f3n. La noticia de hoy, se remonta a las primeras pruebas de una pirotecnolog\u00eda (uso del fuego) que permit\u00eda la elaboraci\u00f3n de utensilios de \u201cpiedra\u201d<span style=\"\">&nbsp; <\/span>m\u00e1s \u00fatiles que los derivados directamente de materiales frescos. Y decimos \u201cpiedra\u201d, porque en realidad se trataba de <span style=\"\">&nbsp;<\/span>\u201csilicretas\u201d o \u201csilicretas\u201d, es decir de horizontes endurecidos de suelos muy evolucionados, que al ser tratados por aquellos \u201cingenieros\u201d, sufr\u00edan cambios en sus propiedades. Hablamos de las costas de Sud\u00e1frica, nada m\u00e1s y nada menos que entre<span style=\"\">&nbsp;&nbsp; <\/span>72.000-140.000 a\u00f1os atr\u00e1s, mucho tiempo antes de que acabara la \u00faltima glaciaci\u00f3n. En cualquier caso, estudios australianos constatan el uso de las mencionadas <a href=\"http:\/\/en.wikipedia.org\/wiki\/Silcrete\">silcretas<\/a> en aqu\u00e9l continente (donde abundan quiz\u00e1s m\u00e1s que en los restantes), por sus moradores abor\u00edgenes, en las que tambi\u00e9n se menciona \u201ca veces\u201d su posible tratamiento pirotecnol\u00f3gico. <o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<img decoding=\"async\" src=\"\/blogs\/universo\/wp-content\/blogs.dir\/42\/files\/255\/o_Silicreta%20Science%20Daily.jpg\" width=\"431\" height=\"318\"><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><a href=\"http:\/\/www.sciencedaily.com\/releases\/2009\/08\/090813142137.htm\">Artefactos en base a material de silicretas<o:p><\/o:p><\/a><\/span><\/p>\n<p class=\"MsoNormal\"><span class=\"MsoHyperlink\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><a href=\"http:\/\/www.sciencedaily.com\/releases\/2009\/08\/090813142137.htm\">de la noticia tratada. Fuente: Sciencedaily <\/a><\/span><\/span><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Bookman Old Style&quot;;\">Y ahora la lamentable, una vez m\u00e1s, la fastidiosa \u201ccoletilla final\u201d. Ya sab\u00e9is que \u00faltimamente a este sistema de bit\u00e1coras, por aquello de los calores, parece ser que se niega a enlazar los post que escribimos, pero no ocurre lo mismo con cualquier otro material que circule por el ciberespacio. Si cuando lee este estamos en tal trance, debe copiar el t\u00edtulo de nuestros post previos y a\u00f1adirlo a su buscador favorito. R\u00e1pidamente encontrar\u00e1 el post, al teclear tambi\u00e9n \u201cUniverso Invisible\u201d. Este tema ya comienza a parecer de ciencia ficci\u00f3n, por pensar bien.<\/span><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p><\/o:p><\/span><\/p>\n<p>  <!--more--><link rel=\"File-List\" href=\"file:\/\/\/C:%5CDOCUME%7E1%5CJuanjo%5CCONFIG%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml\"><o:smarttagtype namespaceuri=\"urn:schemas-microsoft-com:office:smarttags\" name=\"City\"><\/o:smarttagtype><o:smarttagtype namespaceuri=\"urn:schemas-microsoft-com:office:smarttags\" name=\"place\"><\/o:smarttagtype><o:smarttagtype namespaceuri=\"urn:schemas-microsoft-com:office:smarttags\" name=\"country-region\"><\/o:smarttagtype><o:smarttagtype namespaceuri=\"urn:schemas-microsoft-com:office:smarttags\" name=\"PlaceName\"><\/o:smarttagtype><o:smarttagtype namespaceuri=\"urn:schemas-microsoft-com:office:smarttags\" name=\"PlaceType\"><\/o:smarttagtype><!--[if !mso]><object  classid=\"clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D\" id=ieooui><\/object> \n\n<style> st1\\:*{behavior:url(#ieooui) } --><\/p>\n<style> <!--  \/* Font Definitions *\/  @font-face \t{font-family:\"Comic Sans MS\"; \tpanose-1:3 15 7 2 3 3 2 2 2 4; \tmso-font-charset:0; \tmso-generic-font-family:script; \tmso-font-pitch:variable; \tmso-font-signature:647 0 0 0 159 0;}  \/* Style Definitions *\/  p.MsoNormal, li.MsoNormal, div.MsoNormal \t{mso-style-parent:\"\"; \tmargin:0pt; \tmargin-bottom:.0001pt; \tmso-pagination:widow-orphan; \tfont-size:12.0pt; \tfont-family:\"Times New Roman\"; \tmso-fareast-font-family:\"Times New Roman\";} a:link, span.MsoHyperlink \t{color:#000099; \tmso-text-animation:none; \ttext-decoration:none; \ttext-underline:none; \ttext-decoration:none; \ttext-line-through:none;} a:visited, span.MsoHyperlinkFollowed \t{color:purple; \ttext-decoration:underline; \ttext-underline:single;} @page Section1 \t{size:612.0pt 792.0pt; \tmargin:72.0pt 90.0pt 72.0pt 90.0pt; \tmso-header-margin:36.0pt; \tmso-footer-margin:36.0pt; \tmso-paper-source:0;} div.Section1 \t{page:Section1;} --> <\/style>\n<p><!--  \/* Style Definitions *\/  table.MsoNormalTable \t{mso-style-name:\"Tabla normal\"; \tmso-tstyle-rowband-size:0; \tmso-tstyle-colband-size:0; \tmso-style-noshow:yes; \tmso-style-parent:\"\"; \tmso-padding-alt:0pt 5.4pt 0pt 5.4pt; \tmso-para-margin:0pt; \tmso-para-margin-bottom:.0001pt; \tmso-pagination:widow-orphan; \tfont-size:10.0pt; \tfont-family:\"Times New Roman\";} -->  <\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\">Estas evidencias <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">inducen a pensar que cuando los humanos modernos emigraron a Europa durante la \u00faltima edad glacial, hace 50.000-60.000<\/span><\/b> <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">a\u00f1os, ya atesoraban un desarrollo cognitivo <\/span><\/b><span style=\"color: rgb(51, 102, 255);\"><\/span>(que posiblemente inclu\u00eda el lenguaje), <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">cultural y tecnol\u00f3gico muy superior al de los neardentales <\/span><\/b>que por aqu\u00e9l entonces habitaban el denominado \u201cviejo continente\u201d. Por tanto, su superioridad no tan solo afectaba a lo que podr\u00edamos denominar inteligencia individual, sino que iba mucho m\u00e1s all\u00e1. <o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\">Debemos advertir que <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">las notas de prensa que hoy exponemos, hablan de silcretas como roca, y no como horizontes del suelo<\/span><\/b>. La espa\u00f1ola no parece ser la culpable (eso s\u00ed que es novedad) por cuanto, como siempre reproduce parcialmente la anglosajona. Y es ya en la primera en donde aparece tal problema. Visto lo visto, hemos indagado en Internet unos minutos. No he logrado detectar p\u00e1ginas Webs que constaten que a \u201calg\u00fan tipo de rocas\u201d se les denomine \u201c<a href=\"http:\/\/en.wikipedia.org\/wiki\/Silcrete\">silcretes<\/a>\u201d. Por tanto, inferimos que los autores del trabajo, o se explicaron mal (lo m\u00e1s probable), o no tienen ni idea de la naturaleza del material sometido a <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">pirotecnolog\u00eda<\/span><\/b>. Sin embargo, cabe la posibilidad de que nos equivoquemos, si bien lo dudamos, ya que no resulta ser un vocablo excesivamente com\u00fan en el ciberespacio. <o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;; color: rgb(51, 102, 255);\">\u00bfPero porqu\u00e9 las silcretas?<\/span><\/b><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"> Francamente no estoy seguro. Sin embargo, debemos tener en cuenta algunas de las <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">singularidades de los paisajes africanos, australianos y <\/span><\/b>de parte de los latinoamericanos. En general, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">tales espacios geogr\u00e1ficos albergan suelos muy desarrollados y perfiles de alteraci\u00f3n o regolitos de varias decenas de metros.<\/span><\/b> Bajo estas condiciones, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">encontrar materiales litol\u00f3gicos duros resulta dif\u00edcil<\/span><\/b>, por cuanto se encuentran a muchos metros de profundidad. Sin embargo, a<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">lgunos tipos de suelos o edafotaxa de estos paisajes (especialmente en los \u00e1ridos y semi\u00e1ridos) atesoran horizontes endurecidos de mucha consistencia<\/span><\/b>.<span style=\"\">&nbsp; <\/span>Ya os hablamos de este tema en el post: \u201c<a href=\"http:\/\/weblogs.madrimasd.org\/universo\/archive\/2008\/11\/05\/105926.aspx\">Horizontes Endurecidos del Suelo (Sobre \u201cCretas\u201d \u201cPetros\u201d \u201cPanes\u201d y \u201cCorazas\u201d)<\/a>\u201d. As\u00ed mismo, tambi\u00e9n comentamos en esta contribuci\u00f3n\u201d <a href=\"\/blogs\/universo2007\/04\/15\/63589.aspx\">Suelos Pobres: Ladrillos Negros y Ladrillos Rojos (Materiales para el Hombre)<\/a>\u201d, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">como otro tipo de cretas o capas del suelo duras<\/span><\/b> (en este caso<b style=\"\"><span style=\"color: rgb(51, 102, 255);\"> plintitas endurecidas y ferricretas<\/span><\/b>) son <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">utilizadas at\u00e1vicamente para la construcci\u00f3n de viviendas por los pueblos abor\u00edgenes africanos<\/span><\/b>, por las mismas razones. <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Cuando tales superficies con miles de a\u00f1os sufren un proceso de denudaci\u00f3n de los horizontes superficiales de los suelos que los recubren, las mencionadas capas endurecidas afloran hasta la superficie<\/span><\/b>. Debido a que los <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">\u201csolum\u201d que las albergan mucho m\u00e1s resistentes a la erosi\u00f3n<\/span><\/b> que los que carecen de ellas, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">terminan formando resaltes topogr\u00e1ficos como las \u201cmesas\u201d y las cumbres de los \u201cmontes islas\u201d, siendo pues accesibles<\/span><\/b> a los abor\u00edgenes.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<img decoding=\"async\" src=\"\/blogs\/universo\/wp-content\/blogs.dir\/42\/files\/255\/o_Silicreta%20Flirck.jpg\" width=\"446\" height=\"298\"><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><a href=\"http:\/\/www.flickr.com\/photos\/dietmardownunder\">Horizonte superficial de silicreta.<o:p><\/o:p><\/a><\/span><\/p>\n<p class=\"MsoNormal\"><span class=\"MsoHyperlink\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><a href=\"http:\/\/www.flickr.com\/photos\/dietmardownunder\">Fuente: <span style=\"\">Dietmar Down Under&#8217;s photostream &nbsp;<\/span><\/a><\/span><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\">Wikipedia menciona que, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">en ciertos yacimientos en donde se han encontrado, carecen o no afloran tales horizontes endurecidos, por lo que cabe sospechar que fueran motivo de comercio<\/span><\/b> entre unos pueblos y otros. Digamos de paso que las silcretas naturales, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">al someterse a la pirotecnolog\u00eda, adquieren un color rojizo que no lo tienen las originarias<\/span><\/b>, como la foto de Sciencedaily ilustra. Con vistas a llevar a cabo tal estudio, al margen de hacer uso de termoluminiscencia y t\u00e9cnicas basadas en el magnetismo para datar las edades, etc., los autores emularon el proceso t\u00e9rmico mencionado, obteniendo productos semejantes a los detectados en los yacimientos. <o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;; color: rgb(51, 102, 255);\">Los investigadores<\/span><\/b><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"> que llevaron a cabo este trabajo, r<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">ealizan mucho \u00e9nfasis en la capacidad cognitiva que deb\u00eda ser requerida para llevar a cabo este tipo de ingenier\u00eda paleol\u00edtica<\/span><\/b>. No lo dudamos pero quiz\u00e1s se excedan en sus elucubraciones \u00bfQu\u00e9 el lenguaje por aquel entonces ya estuviera plenamente desarrollado? Posiblemente. Sin embargo, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">reiteramos que se trata de una evidencia sobre tecnolog\u00edas <\/span><\/b>(m\u00e1s sofisticadas de las que se presupon\u00edan) que usaron los hombres de la edad de piedra. Nada m\u00e1s. A pesar de todo, si que <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">nos informa que el uso de los tratamientos t\u00e9rmicos precedieron a los previamente usados para la elaboraci\u00f3n de utensilios mec\u00e1nicos y cer\u00e1micos, generando un continuo interesante y desconocido con anterioridad<\/span><\/b>.<span style=\"\">&nbsp; <\/span>Obviamente, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">tal dato apoya la controvertida tesis de que los humanos modernos atesoraban capacidades cognitivas, tecnol\u00f3gicas y sociales superiores a las de los Neardentales,<\/span><\/b> por lo que su adaptabilidad a los avatares del entorno fueron superiores. Pero tambi\u00e9n debemos advertiros que, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">sobre controversia, se publican con cierta frecuencia estudios que avalan una u otra tesis<\/span><\/b>. Dicho de otro modo, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">no se trata de pruebas que puedan considerarse concluyentes<\/span><\/b>. Es plausible que pronto se encuentren nuevas pruebas entre los restos arqueol\u00f3gicos de los neardentales que constaten que ellos tambi\u00e9n usaban tal pirotecnolog\u00eda, aunque les fuera transmitida por los humanos modernos.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p><img decoding=\"async\" src=\"\/blogs\/universo\/wp-content\/blogs.dir\/42\/files\/255\/o_Mesa%20suraustralia%20por%20silicreta.jpg\" width=\"443\" height=\"331\"><br \/><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><o:p>&nbsp;<\/o:p><\/p>\n<p class=\"MsoNormal\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\"><a href=\"http:\/\/www.oz-greetings.com.au\/geology\/article\/23\/-b-STURTS--STONY--DESERT--b-\">Mesa en el sur de australia con capa de silicreta.<o:p><\/o:p><\/a><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span class=\"MsoHyperlink\"><span style=\"font-size: 8pt; font-family: &quot;Comic Sans MS&quot;;\" lang=\"EN-GB\"><a href=\"http:\/\/www.oz-greetings.com.au\/geology\/article\/23\/-b-STURTS--STONY--DESERT--b-\">Fuente: Nature\u2019s cards clips and geology<\/a><\/span><\/span><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\" lang=\"EN-GB\"><o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;; color: rgb(204, 0, 0);\">Juan Jos\u00e9 Ib\u00e1\u00f1ez<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: center;\" align=\"center\"><a name=\"inicio\"><\/a><a href=\"http:\/\/www.madrimasd.org\/informacionidi\/noticias\/noticia.asp?id=40416\"><span style=\"\"><span style=\"font-family: Arial;\">Los primeros humanos modernos utilizaron fuego para construir herramientas mejores y m\u00e1s resistentes<\/span><\/span><span style=\"\"><\/span><\/a><span style=\"\"><span style=\"font-family: Arial;\"><o:p><\/o:p><\/span><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"\"><span style=\"font-size: 9pt; font-family: Arial;\">Investigadores financiados con fondos comunitarios han averiguado <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">m\u00e1s datos sobre la evoluci\u00f3n del comportamiento humano<\/span><\/b>. Su investigaci\u00f3n aclara c\u00f3mo <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">los primeros humanos modernos del sur de \u00c1frica lograron emplear el fuego para mejorar la calidad y eficacia de las herramientas de piedra<\/span><\/b>. <o:p><\/o:p><\/span><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"\"><span style=\"font-size: 9pt; font-family: Arial;\">FUENTE | <\/span><\/span><span style=\"font-size: 9pt; font-family: Arial;\"><a href=\"http:\/\/www.cordis.lu\/\" target=\"_blank\">CORDIS: Servicio de Informaci\u00f3n en I+D Comunitario<\/a>; 23\/08\/2009 <o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\">Sus descubrimientos, publicados en la revista <a href=\"http:\/\/www.sciencemag.org\/\" target=\"_blank\">Science<\/a>, muestran que dichos <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">humanos habr\u00edan comenzado a resolver problemas complejos en el momento en el que se materializ\u00f3 su linaje gen\u00e9tico moderno (hace entre 200.000 y 150.000 a\u00f1os). Estudios anteriores datan el desarrollo de esta capacidad con posterioridad<\/span><\/b>. <o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><br \/> El equipo cient\u00edfico internacional descubri\u00f3 que los<b style=\"\"><span style=\"color: rgb(51, 102, 255);\"> primeros humanos modernos <\/span><\/b>que habitaban las <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">cuevas de<\/span><\/b> las bah\u00edas de Mossel y Still <b style=\"\"><span style=\"color: green;\">(Sud\u00e1frica) hace unos 70.000 a\u00f1os calentaban con fuego y tallaban silcreta (una roca de gran dureza) para fabricar herramientas de piedra. Al calentar la silcreta, estos humanos modificaban la estructura de la roca y la transformaban en una materia prima ideal para la producci\u00f3n de herramientas m\u00e1s sofisticadas<\/span><\/b>.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><br \/> \u00ab<b style=\"\"><span style=\"color: green;\">El uso controlado del fuego fue una revoluci\u00f3n que permiti\u00f3 la cocina, la producci\u00f3n de calor y luz y la protecci\u00f3n frente a depredadores\u00bb<\/span><\/b>, seg\u00fan se indica en el estudio. \u00abEl tratamiento de materiales con calor y todo lo necesario para ello <b style=\"\"><span style=\"color: green;\">marca un avance tecnol\u00f3gico importante, en el que el fuego comenz\u00f3 a manipularse como herramienta de ingenier\u00eda<\/span><\/b>.\u00bb<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><br \/> Kyle Brown, autor principal del estudio, estudiante de doctorado de la <a href=\"http:\/\/www.uct.ac.za\/\" target=\"_blank\">Universidad de Ciudad del Cabo<\/a> (Sud\u00e1frica) y director de los trabajos de laboratorio y campo en la Bah\u00eda Mossel para el <a href=\"http:\/\/iho.asu.edu\/\" target=\"_blank\">Instituto de los Or\u00edgenes Humanos de la Universidad Estatal de Arizona<\/a> (ASU, Estados Unidos), afirm\u00f3: \u00abNuestros descubrimientos sobre el tratamiento con calor muestran que <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">estos primeros humanos modernos controlaban el fuego de manera sofisticada y precisa.<\/span><\/b>\u00bb<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><br \/> \u00abHemos mostrado que <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">los primeros humanos modernos de hace 72.000 a\u00f1os, y quiz\u00e1 de hace 164.000, procedentes de las costas de Sud\u00e1frica utilizaban hogares en un complejo proceso que consist\u00eda en calentar la piedra y cambiar sus propiedades<\/span><\/b>. Esta t\u00e9cnica era conocida como <b style=\"\"><span style=\"color: green;\">tratamiento t\u00e9rmico<\/span><\/b>\u00bb, a\u00f1adi\u00f3.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><br \/> Curtis Marean, profesor de la ASU, director del proyecto y coautor del estudio, se\u00f1al\u00f3 que <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">alguien debi\u00f3 descubrir que era m\u00e1s f\u00e1cil tallar la roca cuando se le aplicaba calor<\/span><\/b>. \u00abDespu\u00e9s, este conocimiento se fue transmitiendo y, de una manera particularmente humana, la t<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">ecnolog\u00eda implicada creci\u00f3 lentamente en complejidad al aumentar la sofisticaci\u00f3n del control del proceso de calentamiento, enfriamiento y tallado<\/span><\/b>\u00bb, explic\u00f3. <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Este valioso proceso tecnol\u00f3gico se cre\u00f3 de forma paralela a la aparici\u00f3n del conocimiento complejo en humanos y se habr\u00eda extendido con tanta rapidez debido a que el lenguaje estaba lo suficientemente desarrollado<\/span><\/b> como para ser utilizado como herramienta de ense\u00f1anza y aprendizaje.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><\/p>\n<p> <b style=\"\"><span style=\"color: green;\">En un art\u00edculo complementario escrito por John Webb y Marian Domanski se explica que el empleo de fuego \u00abcomo herramienta de ingenier\u00eda es uno de los primeros pasos en la evoluci\u00f3n de los medios mediante los que los humanos controlan su entorno\u00bb<\/span><\/b>. Tambi\u00e9n se afirma que<b style=\"\"><span style=\"color: rgb(51, 102, 255);\"> el tratamiento t\u00e9rmico se origin\u00f3 en \u00c1frica pr\u00e1cticamente al mismo tiempo que los \u00abindicios generalizados de comportamiento simb\u00f3lico que se\u00f1alan el desarrollo de una capacidad cognitiva cada vez m\u00e1s compleja<\/span><\/b>\u00bb. A\u00f1adieron que \u00abal permitir la <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">fabricaci\u00f3n de herramientas m\u00e1s eficientes, el tratamiento t\u00e9rmico debi\u00f3 desempe\u00f1ar una funci\u00f3n b\u00e1sica a la hora de permitir una r\u00e1pida expansi\u00f3n humana desde los entornos relativamente favorables de Sud\u00e1frica hasta los m\u00e1s hostiles y fr\u00edos de Europa<\/span><\/b>\u00bb.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><\/p>\n<p> <b style=\"\"><span style=\"color: green;\">Los Neandertales europeos \u00abno deb\u00edan conocer esta t\u00e9cnica<\/span><\/b>, por lo que puede que los primeros humanos modernos tuvieran una ventaja evolutiva al avanzar hasta Eurasia\u00bb, especulan los Drs. Webb y Domanski. El apoyo comunitario a la investigaci\u00f3n parti\u00f3 de una beca Marie Curie de salida a terceros pa\u00edses del S\u00e9ptimo Programa Marco (7PM).<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: center;\" align=\"center\"><span style=\"font-family: Arial;\"><a href=\"http:\/\/www.sciencedaily.com\/releases\/2009\/08\/090813142137.htm\"><span style=\"\" lang=\"EN-GB\">Early Modern Humans Used Fire To Engineer Tools From Stone Complex Cognition Older Than 72000 Years?<\/span><\/a><\/span><span style=\"font-family: Arial;\" lang=\"EN-GB\"><o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: center;\" align=\"center\"><span style=\"font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: green;\" lang=\"EN-GB\">ScienceDaily (Aug. 14, 2009) <\/span><\/b><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">\u2014 <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Evidence that early modern humans living on the coast of the far southern tip of Africa 72,000 years ago employed pyrotechnology<\/span><\/b> \u2013 the controlled use of fire \u2013 to <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">increase the quality and efficiency of their stone tool manufacturing process<\/span><\/b>, is being reported in the <b style=\"\"><span style=\"color: green;\">Aug. 14 issue of the journal Science<\/span><\/b>.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">An international team of researchers, including three from the <\/span><st1:place><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Institute<\/span><\/st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">  of <\/span><st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Human Origins<\/span><\/st1:placename><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> at <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Arizona State University<\/span><\/b>, deduce that \u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">this technology required a novel association between fire, its heat, and a structural change in stone with consequent flaking benefits.<\/span><\/b>\u00bb Further, their findings<b style=\"\"><span style=\"color: green;\"> ignite the notion of complex cognition in these early engineers<\/span><\/b>. \u00abOur illumination of the heat treatment process shows that these <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">early modern humans commanded fire in a nuanced and sophisticated manner<\/span><\/b>,\u00bb says lead author Kyle Brown, a doctoral candidate at the <\/span><st1:place><st1:placetype><b style=\"\"><span style=\"color: rgb(51, 102, 255);\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">University<\/span><\/span><\/b><\/st1:placetype><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: rgb(51, 102, 255);\" lang=\"EN-GB\"> of <\/span><\/b><st1:placename><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: rgb(51, 102, 255);\" lang=\"EN-GB\">Cape Town<\/span><\/b><\/st1:placename><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">, and field and lab director in <\/span><st1:place><st1:city><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Mossel Bay<\/span><\/st1:city><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">,  <\/span><st1:country-region><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">South Africa<\/span><\/st1:country-region><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">, for ASU&#8217;s <\/span><st1:place><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Institute<\/span><\/st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">  of <\/span><st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Human Origins<\/span><\/st1:placename><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: rgb(51, 102, 255);\" lang=\"EN-GB\">\u00abWe show that early modern humans at 72,000 years ago, and perhaps as early as 164,000 years ago in coastal South Africa, were using carefully controlled hearths in a complex process to heat stone and change its properties<\/span><\/b><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">, the process known as heat treatment,\u00bb explains Brown. \u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Heat treatment technology begins with a genius moment<\/span><\/b> \u2013 someone discovers that heating stone makes it easier to flake,\u00bb says Curtis Marean, project director and a co-author on the paper. Marean is a paleoanthropologist with the <\/span><st1:place><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Institute<\/span><\/st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">  of <\/span><st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Human Origins<\/span><\/st1:placename><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> and a professor in the <\/span><st1:place><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">School<\/span><\/st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">  of <\/span><st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Human Evolution<\/span><\/st1:placename><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> and Social Change at <\/span><st1:place><st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Arizona<\/span><\/st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> <\/span><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">State<\/span><\/st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> <\/span><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">University<\/span><\/st1:placetype><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">&#8216;s <\/span><st1:place><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">College<\/span><\/st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">  of <\/span><st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Liberal Arts<\/span><\/st1:placename><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> and Sciences. \u00abThis knowledge is then passed on, and in a way unique to humans, the technology is slowly ratcheted up in complexity as the control of the heating process, cooling and flaking grows in sophistication,\u00bb Marean says.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: rgb(51, 102, 255);\" lang=\"EN-GB\">This creates a long-chain technological process that the researchers explain requires a complex cognition, and probably language, to learn and teach<\/span><\/b><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">. The heating transformed <b style=\"\"><span style=\"color: green;\">a stone called silcrete<\/span><\/b>, which was rather poor for tool making, into an outstanding raw material that a<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">llowed the modern humans to make highly advanced tools<\/span><\/b>.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 10pt; font-family: Arial; color: teal;\" lang=\"EN-GB\">The eureka moment<o:p><\/o:p><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">The focus of Brown&#8217;s research involves experimentally replicating the types of tools and production debris found at African archaeological sites to understand how and why people made and used these tools. \u00abIn numerous field surveys with co-author <b style=\"\"><span style=\"color: green;\">David Roberts, who is a leading expert on silcrete formation<\/span><\/b>, <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">we were unable to locate stone outcrops with material that matched the fine-grained texture and often reddish color of the silcrete artifacts we excavated<\/span><\/b> at Pinnacle Point,\u00bb Brown says. <\/span><span style=\"font-size: 9pt; font-family: Arial;\">\u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">The silcrete we had collected was just not suitable for tool production<\/span><\/b>.\u00bb<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: rgb(51, 102, 255);\" lang=\"EN-GB\">Most of the silcrete they found was intensively flaked<\/span><\/b><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">. <\/span><span style=\"font-size: 9pt; font-family: Arial;\">It was unusual to find a piece larger than a few centimeters. <\/span><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">However, one day in 2007, while Brown and Marean were at the Pinnacle Point Site 5-6 (PP5-6) <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">they found a huge flake of silcrete embedded in ash \u2013 the largest piece of silcrete they had ever seen on an archaeological site<\/span><\/b>, nearly 10 centimeters in diameter. \u00abIt looked like it had been accidentally lost in a fire pit,\u00bb Brown notes. <\/span><span style=\"font-size: 9pt; font-family: Arial;\">He recalls how many of the silcrete tools from the site had a sheen or gloss that reminded him of tools he had examined in North American collections that were heat-treated<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\">.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: rgb(51, 102, 255);\">\u00abThat is when we developed the heat treatment idea<\/span><\/b><span style=\"font-size: 9pt; font-family: Arial;\">,\u00bb Marean says. <\/span><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">\u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">The co-association of the ash cemented to the silcrete, the red color of the silcrete, and its inexplicably large size was the genesis conditions of our eureka moment<\/span><\/b>.\u00bb <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">To test their theory<\/span><\/b>, Brown placed some of the silcrete stone beneath their fire pit one evening, building a hot fire over the top. \u00abWhen I returned to dig the stone out the following day, the results were amazing. <\/span><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: rgb(51, 102, 255);\">After heating, the silcrete became a deep red color and was easily flaked<\/span><\/b><span style=\"font-size: 9pt; font-family: Arial;\">. Most importantly, it looked exactly like silcrete from site PP5-6. <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Using heated silcrete we were then able to produce realistic copies of the actual silcrete tools<\/span><\/b>,\u00bb Brown says.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 10pt; font-family: Arial; color: teal;\" lang=\"EN-GB\">Barbequing rocks<o:p><\/o:p><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">\u00ab<b style=\"\"><span style=\"color: green;\">Here are the beginnings of fire and engineering, the origins of pyrotechnology, and the bridge to more recent ceramic and metal technology<\/span><\/b>,\u00bb Brown says. According to Marean, the <b style=\"\"><span style=\"color: green;\">silcrete bifaces are re-usable tools with many potential functions<\/span><\/b>: effective hunting weapons, excellent knives and items of <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">value for exchange.<\/span><\/b> \u00abThis explains why people would invest so much effort at<b style=\"\"><span style=\"color: rgb(51, 102, 255);\"> wood collection and heat treatment for their production<\/span><\/b>,\u00bb Marean says. And, the hearths used to test their theory \u00abwere designed to mimic what people in the past may have done. <\/span><span style=\"font-size: 9pt; font-family: Arial;\">So, not only did we heat silcrete, but we barbecued (a &#8216;braai&#8217; in South Africa) steaks and chops at the same time as measuring the temperature profiles with our thermocouple,\u00bb Marean says.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 10pt; font-family: Arial; color: teal;\">Symbolic behavior and modern human origins<o:p><\/o:p><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">\u00abOur discovery shows that th<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">ese early modern humans had this complex cognition<\/span><\/b>,\u00bb Brown says. \u00abThis expression of <b style=\"\"><span style=\"color: rgb(51, 102, 255);\">cognitive complexity in technology by these early modern humans on the south coast of South Africa provides further evidence that this locality may have been the origin location for the lineage that leads to all modern humans, which appeared between 100,000 and 200,000 years ago in Africa<\/span><\/b>,\u00bb explains Marean.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\">\u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">There is no consensus as to when modern human behavior appears, but by 70,000 years ago there is good evidence for symbolic behavior<\/span><\/b>,\u00bb he says. <\/span><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">\u00abMany researchers are looking for technological proxies for complex cognition, and heat treatment is likely one such proxy. \u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Prior to our work, heat treatment was widely regarded as first occurring in Europe at about 25,000 years ago<\/span><\/b>,\u00bb Marean says. \u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">We push this back at least 45,000 years, and, perhaps, 139,000 years, and place it on the southern tip of Africa<\/span><\/b> at Pinnacle Point.\u00bb The African location was at the center of another discovery by Marean \u2013 <b style=\"\"><span style=\"color: green;\">the documentation of the earliest evidence for exploitation of marine foods and modification of pigments \u2013 r<\/span><\/b>eported in the Oct. 17, 2007, journal Nature.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">\u00ab<b style=\"\"><span style=\"color: rgb(51, 102, 255);\">Combined, these results sharply advance our knowledge of modern human origins, and show that something special in human cognition was happening on the coastline of South Africa during this crucial final phase in human origins<\/span><\/b>,\u00bb Marean says. He adds that some time a<b style=\"\"><span style=\"color: green;\">round 50,000 to 60,000 years ago, \u00abthese modern humans left the warm confines of <\/span><\/b><\/span><st1:place><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: green;\" lang=\"EN-GB\">Africa<\/span><\/b><\/st1:place><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: green;\" lang=\"EN-GB\"> and penetrated into the colder glacial environment of <\/span><\/b><st1:place><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: green;\" lang=\"EN-GB\">Europe<\/span><\/b><\/st1:place><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: green;\" lang=\"EN-GB\"> and <\/span><\/b><st1:place><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: green;\" lang=\"EN-GB\">Asia<\/span><\/b><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">,<b style=\"\"><span style=\"color: green;\"> where they encountered Neanderthals<\/span><\/b>.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">\u00ab<b style=\"\"><span style=\"color: green;\">By 35,000 years ago these Neanderthal populations were mostly extinct, and modern humans dominated the land from Spain to China to Australia<\/span><\/b>,\u00bb Marean says. \u00ab<b style=\"\"><span style=\"color: green;\">The command of fire, documented by our study of heat treatment, provides us with a potential explanation for the rapid migration of these Africans across glacial Eurasia \u2013 they were masters of fire and heat and stone, a crucial advantage as these tropical people penetrated the cold lands of the Neanderthal,<\/span><\/b>\u00bb says Marean. <\/span><span style=\"font-size: 9pt; font-family: Arial;\">NSF, others fund SACP4<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Other members of the research team and co-authors of \u00abFire As an Engineering tool of Early Modern Humans,\u00bb include David Baun, University of Cape Town; Andy I.R. Herries, University of New South Wales and University of Liverpool; Zenobia Jacobs and Michael C. Meyer, University of Wollongong, Australia; Changal Tribolo, CNRS-University of Bordeaux, France; David L. Roberts, Council for Geoscience, Republic of South Africa; and Jocelyn Bernatchez, Institute of Human Origins, ASU. They work together on the South African Coast Paleoclimate, Paleoenvironment, Paleoecology, Paleoanthropology Project, known as SACP4, which is directed by Marean, funded by the National Science Foundation and the Hyde Family Foundation, and supported by Arizona State University research and academic units including the Institute of Human Origins, Institute for Social Science Research, and School of Human Evolution and Social Change in the College of Liberal Arts and Sciences. \u00abOur team, working at Pinnacle Point near <\/span><st1:place><st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Mossel<\/span><\/st1:placename><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> <\/span><st1:placetype><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">Bay<\/span><\/st1:placetype><\/st1:place><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">, is a leader in revealing the process of how we became who we are today, and we are doing this with state-of-the-art fieldwork and laboratory analysis at this locality,\u00bb Marean says.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">He notes the specifics of the discovery involved <b style=\"\"><span style=\"color: green;\">combining thermoluminescence, magnetic analysis, optically stimulated luminescence dating, experimental stone tool production, mechanical testing, and field archaeology<\/span><\/b>.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 9pt; font-family: Arial; color: green;\" lang=\"EN-GB\">Pie de Foto:<\/span><\/b><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\"> Adapted from materials provided by <\/span><span style=\"font-size: 9pt; font-family: Arial;\"><a href=\"http:\/\/www.asu.edu\/\" target=\"_blank\"><span style=\"\" lang=\"EN-GB\">Arizona State University<\/span><\/a><\/span><span style=\"font-size: 9pt; font-family: Arial;\" lang=\"EN-GB\">.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\">Evidence reported in the Aug. 14 issue of the journal Science shows that early humans living on the southern coast of Africa 72,000 years ago used a complex heat treatment process to manufacture blades and bifacial tools. Unheated silcrete (left) can show dramatic changes in color and texture after heating and flaking (right). An international team, including three researchers from the Institute of Human Origins at Arizona State University, note that silcrete is not found closer than 5 kilometers from their excavation at Pinnacle Point, Mossel Bay, South Africa, and that most pieces found are extensively flaked. (Photo by Kyle Brown\/South African Coast Paleoclimate, Paleoenvironment, Paleoecology, Paleoanthropology Project)<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><b style=\"\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;; color: green;\">A favor de las tesis aqu\u00ed mostradas, ver tambi\u00e9n la siguiente nota de Prensa<o:p><\/o:p><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: center;\" align=\"center\"><span style=\"font-family: Arial;\"><a href=\"http:\/\/www.madrimasd.org\/informacionidi\/noticias\/noticia.asp?id=40535&amp;origen=notiweb\">La cultura en la Edad de Piedra m\u00e1s avanzada de lo que se cre\u00eda seg\u00fan cuentas paleol\u00edticas<\/a><o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"background: white none repeat scroll 0% 0%; text-align: justify; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;\"><span style=\"font-size: 9pt; font-family: Arial; color: black;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 9pt; font-family: Arial;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><span style=\"font-family: &quot;Comic Sans MS&quot;; color: green;\">Alguna documentaci\u00f3n adicional en la Web.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\"><o:p>&nbsp;<\/o:p><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\">Ver <a href=\"http:\/\/www.encyclopedia.com\/doc\/1O112-plslsdrcrstsclcrtslcrtgyp.html\">enlace sobre silicretas y otros horizontes endurecidos<\/a> aqu\u00ed.<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\">Presentaci\u00f3n en<a href=\"http:\/\/www.uclm.es\/profesorado\/egcardenas\/meteorizaci%C3%83%C2%B3n.pdf\"> ppt sobre meteorizaci\u00f3n y edafog\u00e9nesis<\/a>, con informaci\u00f3n a cerca de la formaci\u00f3n de silicretas. Y pone:<o:p><\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\"><o:p>&nbsp;<\/o:p><\/span><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-size: 10pt; font-family: &quot;Comic Sans MS&quot;;\">Las <a href=\"http:\/\/www.australianarchaeologicalassociation.com.au\/attenbrow_etal_2004\">silicretas han sido tambi\u00e9n utilizadas por otros pueblos abor\u00edgenes<\/a> con vistas a elaborar sus utensilios.<o:p><\/o:p><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Diversos estudios recientes van retrotrayendo la evoluci\u00f3n cultural y humana hacia tiempos cada vez m\u00e1s remotos. Es habitual, en la literatura reciente, que se asocien las tecnolog\u00edas menos rudimentarias al Neol\u00edtico o a \u00e9pocas anteriores, aunque no muy distantes. Sin embargo, durante los \u00faltimos meses, parecen acumularse evidencias de que ya en el paleol\u00edtico remoto el ser humano atesoraba una tecnolog\u00eda hasta ahora insospechada, as\u00ed como un desarrollo cognitivo individual que permiti\u00f3 ir construyendo redes culturales que fomentaban el comercio y la cooperaci\u00f3n. La noticia de hoy, se remonta a las primeras pruebas de una pirotecnolog\u00eda (uso del fuego) que\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[590,599,598],"tags":[],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/124048"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=124048"}],"version-history":[{"count":2,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/124048\/revisions"}],"predecessor-version":[{"id":134983,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/124048\/revisions\/134983"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=124048"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=124048"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=124048"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}