CINXE.COM

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN" "http://www.w3.org/MarkUp/Wilbur/HTML32.dtd"> <html>  <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("http://news.nationalgeographic.com:80/news/2002/10/1024_021024_ChileAtacama.html","20021028200916","https://web.archive.org/","web","/_static/", "1035835756"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" />  <meta http-equiv="content-type" content="text/html;charset=iso-8859-1"> <title>Ancient Chile Migration Mystery Tied to Drought</title> <meta name="keywords" content="Ancient Chile Migration Mystery Tied to Drought"> <meta name="description" content="Researchers studying prehistoric human migration patterns in Chile's Atacama Desert have long been perplexed by a pattern of occupation, abandonment, and recolonization in the region and what accounted for it. New findings link the situation to climate change&#151;specifically, bouts of extreme drought.">  <script language="javascript">  // detects the url of the current page //function EmailURL(url) { var url =window.location document.writeln('<INPUT type="Hidden" name="url" value="'+ url +'">'); //alert(url); //}  // Current Date  </script> <noscript> <link rel="stylesheet" href="/web/20021028200916cs_/http://news.nationalgeographic.com/news/ax/ngnews.css" type="text/css"> </noscript> </head> <body background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/page.gif" bgcolor="#ffffff" topmargin="0" leftmargin="0" marginwidth="0" marginheight="0"> <a name="top"></a>  <table border="0" cellpadding="2" cellspacing="0" width="100%" bgcolor="black"> <tr> <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" align="left"><a href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/" title="Go to nationalgeographic.com's Home Page"><img height="27" width="226" src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/title_nglogo.gif" border="0" alt="nationalgeographic.com"></a></td> <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" align="right"><img height="27" width="194" src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/title_ngmetatools_new.gif" border="0" usemap="#title_ngmetatools" alt="Tools"> <map name="title_ngmetatools"><area href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/search.html" coords="45,3,84,23" shape="rect" title="Search all of nationalgeographic.com. Exits the News site."><area href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/" coords="1,2,35,23" shape="rect" title="Go to nationalgeographic.com's Home Page. Exits the News site."><area href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/community/register.html" coords="94,4,187,23" shape="rect" title="Get Email Updates"></map></td> </tr> </table>  <table border="0" cellpadding="4" cellspacing="0" width="100%"> <tr valign="middle"> <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/head.gif" width="80%" bgcolor="#000000"> <div align="center"> <a href="/web/20021028200916/http://news.nationalgeographic.com/index.html" title="Go to nationalgeographic.com News Home."><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/news_logo.gif" width="167" height="60" border="0"></a></div> </td> <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/pattern.gif" width="468" align="right" bgcolor="#000000"> <div align="right">  <script language="JavaScript1.1"> var bust; if (typeof bust == 'undefined') { bust = Math.floor(1000000*Math.random()); } if ((!document.images && navigator.userAgent.indexOf('Mozilla/2.') >= 0) || navigator.userAgent.indexOf("WebTV")>= 0) { document.write('<a href="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/jump/ng.news/newscontent;sz=468x60;tile=1;ord='+bust+'">'); document.write('<img src="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/ad/ng.news/newscontent;sz=468x60;tile=1;ord='+bust+'" border="0" height="60" width="468"></a>'); } else { document.write('<scr' + 'ipt language="JavaScript1.1" SRC="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/adj/ng.news/newscontent;dcopt=ist;sz=468x60;tile=1;ord='+bust+'">'); document.write('<a href="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/jump/ng.news/newscontent;sz=468x60;tile=1;ord='+bust+'">'); document.write('<img src="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/ad/ng.news/newscontent;sz=468x60;tile=1;ord='+bust+'" border="0" height="60" width="468"></a>'); document.write('</scr' + 'ipt>'); } </script> <noscript> <a href="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/jump/ng.news/newscontent;sz=468x60;tile=1;ord=20021017123955"> <img src="https://web.archive.org/web/20021028200916im_/http://ad.doubleclick.net/ad/ng.news/newscontent;sz=468x60;tile=1;ord=20021017123955" border="0" height="60" width="468"></a> </noscript>  </div> </td> </tr> </table>  <table border="0" cellpadding="3" cellspacing="0" width="100%"> <tr> <td bgcolor="#214255" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/topnav.gif"> <table border="0" cellpadding="0" cellspacing="2"> <tr valign="middle">  <form name="seek" method="get" action="/web/20021028200916/http://news.nationalgeographic.com/cgi-bin/search.cgi"> <input type="hidden" name="search_tags" value="t"> <input type="hidden" name="search_tags" value="B"> <input type="hidden" name="search_tags" value="h"> <input type="hidden" name="search_tags" value="e"> <input type="hidden" name="index" value="website.swish"> <input type="hidden" name="numpp" value="25"> <input type="hidden" name="results" value="0"> <td bgcolor="#214255" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html"> <div class="topnav"><span class="topnav">Search at nationalgeographic.com  </span></div> </td> <td bgcolor="#214255" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html"><input type="text" name="search" size="18" maxlength="512"></td> <td bgcolor="#214255" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html"><input type="image" src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/go_button.gif" border="0" width="21" height="24" alt="Press Return to Search"></td> </form> </tr> </table> </td>  <td bgcolor="#214255" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/topnav.gif" class="topnav"> <div class="topnav" align="right"> Also see: <a href="https://web.archive.org/web/20021028200916/http://news.nationalgeographic.com/" title="nationalgeographic.com News Home">Today's Top Stories</a><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" width="14" height="1" border="0" suppress="true"> </div> </td> </tr> </table>  <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr valign="top" height="13"> <td bgcolor="#336666" colspan="2" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_top.gif" height="13"><br></td> <td bgcolor="#ffffff" colspan="5" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/body_top.gif" height="13"><br></td> <td bgcolor="#336666" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_top.gif" width="14" valign="top" align="left" height="13"><br></td> </tr> <tr> <td bgcolor="#3366666" width="12" valign="bottom" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_left.gif"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" border="0" alt="" width="12" height="1"></td>  <td bgcolor="#3366666" width="130" valign="top" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html"><p class="nav"><span class="navsmall"><b>This Story</b></span><br><b>Archaeology & Paleontology<br><p class="nav">- <a href="#related">Related Sites & Stories<img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/down_arrow.gif" width="10" height="6" alt="" border="0"></a></p>  <p class="nav">- <a href="/web/20021028200916/http://news.nationalgeographic.com/news/ax/emailnews2.cgi" onmouseover="self.status='Email this story.';return true" onmouseout="self.status='';" title="Email this story.">E-mail this story</a></p> <br>  <div width="130"><span class="navsmall"> Sponsored in part by</span><br><br>  <script language="javaScript"> var bust; if (typeof bust == 'undefined') { bust = Math.floor(1000000*Math.random()); } document.write('<iframe width=120 height=60 marginwidth=0 marginheight=0 hspace=0 vspace=0 frameborder=0 scrolling=no bordercolor="#000000" SRC="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/adi/ng.news/newscontent;sz=120x60;tile=2;ord='+bust+'">'); document.write('<scr' + 'ipt language="JavaScript1.1" src="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/adj/ng.news/newscontent;abr=!ie;sz=120x60;tile=2;ord='+bust+'">'); document.write('</scr' + 'ipt>'); document.write('</iframe>'); </script> <noscript> <a href="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/jump/ng.news/newscontent;abr=!ie;sz=120x60"> <img width="120" height="60" border="0" src="https://web.archive.org/web/20021028200916im_/http://ad.doubleclick.net/ad/ng.news/newscontent;abr=!ie;sz=120x60;tile=2;ord=0000000"></a> </noscript>  <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" width="120" height="1" border="0"> </div> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" width="130" height="1" border="0" alt=""> </td>  <td bgcolor="#ffffff" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_right.gif" width="4%" valign="bottom" bgcolor="#ffffff"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="25" height="1" border="0"></td>  <td bgcolor="#ffffff" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" valign="top" width="70%">  <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" width="350" height="3" alt="" suppress="true"><br> <big class="storyhed">Ancient Chile Migration Mystery Tied to Drought</big><p> <div class="byline">Hillary Mayell <br>for National Geographic News<br> October 24, 2002</div><br>  <div class="deck">  Researchers studying prehistoric human migration patterns in northern Chile's Atacama Desert have concluded that a mysterious pattern of early occupation and abandonment of the region was related to climate change. <p> Humans first occupied the high-altitude desert, which extends from the Pacific Ocean to the base of the Andes, from around 13,000 to 9,500 years ago. The region was then more or less abandoned until around 4,500 years ago, when people began returning. <p> This occupation, abandonment, and recolonization pattern has long intrigued archaeologists. One possible explanation was that the region may have had an inhospitable environment. Or the pattern could simply reflect holes in the archaeological record or some cultural bias at the time. <p></div> </td>  <td bgcolor="#ffffff" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" width="5%" valign="top"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="20" height="1" border="0"></td>  <td bgcolor="#ffffff" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" width="182" valign="top">  <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/2001/05/images/021024_cave.jpg" height="276" width="180" border="0" alt="Atacama Desert, Chile"> <div align="right"> <p class="cutline">By surveying caves like this one, called Tuina-5, along with the presence of ancient lakes and wetlands, researchers have compiled a scenario of likely human migration and occupation by Paleoindians in northern Chile and the forces that drove it.<br><br><i>Photograph by Martin Grosjean</i><br><br>View a dynamic map of the <a href="https://web.archive.org/web/20021028200916/http://plasma.nationalgeographic.com/mapmachine/index.html?id=362&size=medium&left=-78.41&bottom=-28.22&right=-60.41&top=-16.5&point=-69.41011449999999,-22.3557205&text=Atacama%20desert" target="_new">Atacama Desert </a>region of Chile. Peru, Bolivia, Paraguay, and Argentina are included as reference countries: <a href="https://web.archive.org/web/20021028200916/http://plasma.nationalgeographic.com/mapmachine/index.html?id=362&size=medium&left=-78.41&bottom=-28.22&right=-60.41&top=-16.5&point=-69.41011449999999,-22.3557205&text=Atacama%20desert" target="_new">GO >></a> <br> </div>  <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" width="180" height="1" border="0" alt=""> </td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" width="3%" valign="bottom" bgcolor="#ffffff"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="10" height="1" border="0"></td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_left.gif" width="14" valign="bottom" bgcolor="#006666"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="14" height="1" border="0"></td> </tr> </table>  <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td bgcolor="#336666" width="12" valign="bottom" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_left.gif"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" width="12" height="1" border="0" alt=""></td>  <td bgcolor="#336666" width="130" valign="top" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html">  <br> <p class="nav"><span class="navsmall"><b>More News</b></span><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/adventure.html">Adventure & Exploration</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/archaeology.html">Archaeology & Paleontology</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br>  <a href="/web/20021028200916/http://news.nationalgeographic.com/news/animals.html">Animals & Nature</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/science.html">Science & Technology</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br>  <a href="/web/20021028200916/http://news.nationalgeographic.com/news/history.html">People & Culture</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/diary.html">Diary of the Planet</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br>  <a href="/web/20021028200916/http://news.nationalgeographic.com/news/environment.html">The Environment</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/travel.html">Travel</a><br><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/ngchannel.html">National Geographic Today</a><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="1" height="7" border="0"><br><br><br> <span class="navsmall"><b>Special Series</b></span><br> <a href="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/clk;4438937;7367811;w?http://news.nationalgeographic.com/sonydigitallifestyles">Digital Lifestyles:<br>feature by Sony</a><br><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/earthpulse.html">EarthPulse</a><br><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/outthere.html">National Geographic Out There</a><br><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/news/volvonews.html">Volvo Ocean Race</a><br><br> <a href="/web/20021028200916/http://news.nationalgeographic.com/aig.html">Mount Everest Expedition</a><br><br> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="130" height="7" border="0"><br> <br>  </p> <img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" width="130" height="1" border="0" alt=""> </td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_right.gif" width="4%" valign="bottom" bgcolor="#ffffff"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="25" height="1" border="0"></td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" valign="top" bgcolor="#ffffff" width="70%"><div class="storybody"> <p> By matching climate and archaeological records, the researchers concluded that environmental conditionsspecifically, bouts of extreme droughtexplain the unusual pattern. <p> <b>An Archaeological Puzzle</b> <p> The team of two archaeologists and a geoscientist reached their conclusion based on their survey of archaeological sites at three elevations: the shorelines of paleo-lakes above 3,600 meters (12,000 feet); caves at elevations between 3,000 to 3,600 meters (12,000 to 9,800 feet); and low-altitude paleo-wetlands at 2,400 meters (7,900 feet). <p> To fill in the archaeological recordthere was only one high-altitude campsite known to have been occupied between 13,000 to 9,500 years agothe scientists adopted a somewhat novel interdisciplinary approach: They recreated the landscape that existed around 15,000 years ago. <p> "We first tried to reconstruct the paleo-environmental conditions in great detail," said Martin Grosjean, a geoscientist at Switzerland's climate research center at the University of Bern. <p> After identifying lake levels, shorelines, springs, and other geological formations, the researchers drew a map of ancient paleo-shorelines. From this they selected the most promising places where people are likely to have lived, then dug thousands of test pits. <p> "The first people arrived in small groups of extremely mobile hunters. They did not build houses, had no architecture of any kind," said Grosjean. <p> Taking the geo-scientific approach enabled the team to find 38 previously unknown high-altitude campsites that were occupied between 13,000 and 9,500 years ago. <p> "The sites are really small, absolutely unspectacular," he said. "The most we might find would be some obsidian flakes, maybe some small fireplaces, usually buried 2 to 5 centimeters [0.8 to 2 inches] below the surface. This is the only way you could find archaeological sites in such a large area." <p> They also found evidence of human occupation in mid-altitude caves and low-altitude wetlands from 13,000 to 9,500 years ago, and then very few people until 4,500 years ago. <p> "Our study shows that this [migration pattern] is realit is not due to an incomplete archaeological surveyand that it is due to hostile environmental conditions that simply were not favorable to human occupation," said Grosjean. <p> <b>Atacama, Then and Now</b> <p> The Atacama Desert is known as the driest place on Earth. Part of it, known as the Salar de Atacama, is a salt flat that so resembles the landscape of Mars that NASA uses it to test its other-planet dune buggies. <p> Today, nothing grows there below 2,500 meters (8,200 feet). "It's a matter of precipitation, not temperature," said Jason Rech, a geologist at Miami University in Ohio who has studied the paleo-environments of the Atacama. <p> As the desert gains altitude, it becomes slightly less arid. "Plants grow at altitudes between 2,500 to 4,300 meters (8,200 to 14,000 feet); higher than that it's just too cold," said Rech. <p> Starting around 15,000 years ago, the climate became much wetter; by 13,500 years ago environmental conditions in the Atacama were hospitable enough that people moved inalmost immediately. <p> "As soon as there were favorable environmental conditions people moved immediately and occupied this area," said Tom Dillehay, an archaeologist at the University of Kentucky who has worked extensively on archaeological sites in South America. <p> A major wet pulse occurred between about 12,000 and 10,000 years ago. <p> "Instead of 200 millimeters [8 inches] of rain annually at high elevations, you'd get around 400 millimeters [15 inches]," said Rech. "The lower boundary of vegetation expanded as much as 1,000 meters [3,300 feet] downslope. Regions near the Salar that today are barren would have been grasslands between 13,000 to 9,500 years ago." <p> These broad grasslands supported the camelid populationsvicuñas and guanacosthat the Paleoindians hunted for roughly 3,500 years. <p> A drastic drop in precipitation starting around 9,500 years ago triggered what archaeologists call the Silencio Arqueològico, a cultural hiatus in the archaeological record. <p> "When vegetation and animal life were abundant, mobile hunters moved into higher elevations," said Grosjean. "They followed game seasonally, establishing camps along the shorelines of higher paleolakes in the summer, and moving to the lower wetlands in the winter. When the lakes started drying up, they left the area until conditions got betteraround 4,500 years later." <p> More humid areas in the rain forests of central and southern Chile and the central highlands of Peru did not experience a Silencio. <p> <b>Peopling of the Americas</b> <p> A second question puzzling archaeologists was why the initial occupation of the Atacama region occurred 1,500 to 2,000 years later than in regions farther south. <p> The "blitzkrieg" hypothesis for the peopling of the Americas proposed in the early 1970s suggested that the first people to arrive in the Americas were big game hunters who moved swiftly, following their prey, to populate the two continents. <p> "If you assume that the Americas were colonized as the result of people crossing the Bering Strait land bridge and then moving down through North America, Central America, and into South America, you would expect at first glance to see people in northern Chile before southern Chile," said Grosjean. <p> Taking into account the different paleo-climate histories of different areas would lead to a different hypothesis, however. <p> "Then you would expect the first people to occupy the most favorable habitats at the time, namely, southern South AmericaPatagonia and south-central Chile," he said. <p> The findings of the Atacama study, published in the October 25 issue of the journal <i>Science,</i> lend support to an alternate hypothesis suggesting that occupation occurred at a slower pace. <p> "In the last 15 years or so, archaeologists have been questioning the rapid-movement model," said Dillehay. "We've come to realize that it takes time to adapt to new environments, and that as people moved into more lush environments, they became more adapted to a broader spectrum of edible plants and smaller animals. The motivation to move on in pursuit of big game just isn't there." <p> Paleo-archaeologists have the task of figuring out where, when, and how prehistoric peoples lived, "frequently based on very little or ephemeral informationa little like connecting the dots," he said. <p> The study's findings argue for more caution in extrapolating possible explanations from one early site to another, and an increased focus on interdisciplinary collaborations, said Dillehay, who wrote a commentary piece on the study in <i>Science.</i> <p> "There are a range of possibilitiescultural, ideological, technological, and ecologicalthat need to be considered when interpreting archaeological finds," he said. <p> The researchers urged the use of interdisciplinary approaches in future studies. Archaeologists and geoscientists have always worked together, but typically the geoscientists are called in to render expert opinions on issues like soil or pollen analysis, said Dillehay. <p> "It took a long-term research approach and commitment to come up with these findings," he continued. "The value of paleo-ecology studies is that they tell us much more about the kinds of landscapes that existed when early peoples were trekking across them and how to go about finding the places where these people might have lived." <p> "Finding 38 sites with very weak human signatures is remarkable," he added. "In a more lush environment where more people lived, we'd probably find 138 sites that would take an eagle's eye to spot." <p> <i>The study of migration patterns of Paleoindians in the Atacama Desert was partly funded by the National Geographic Society.</i> <br> <br> <b>Join the National Geographic Society</b> <br> <br> Join the world's largest nonprofit scientific and educational organization, and help further our mission to increase and diffuse knowledge of the world and all that is in it. Membership dues are used to fund exploration and educational projects and members also receive 12 annual issues of the Society's official journal, <i>National Geographic.</i> Click here for details of our latest subscription offer: <a href="https://web.archive.org/web/20021028200916/https://secure.customersvc.com/servlet/Show?WESPAGE=ng/oct01dup/worldmap/joinin.html&MSRSMAG=NG" target="_new">Go>></a> <p> </div>  <a name="related"></a>  <table border="0" cellpadding="1" cellspacing="0" width="100%" bgcolor="black"> <tr> <td valign="middle" align="center" width="100%"> <table border="0" cellpadding="5" cellspacing="0" width="100%" bgcolor="#ffffff"> <tr>  <td bgcolor="#339999" valign="top"><div class="inline" style="margin-top: -2px;"> <font color="white"><b>Related Stories</b></font></div></td> </tr> <tr> <td valign="top" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/shadow.gif"> <div class="boxed"> <p class="inline">  <a href="https://web.archive.org/web/20021028200916/http://news.nationalgeographic.com/news/2002/09/0917_020919_pilas.html">Maya Hieroglyphs Recount "Giant War"</a> <i></i> <br>  <a href="https://web.archive.org/web/20021028200916/http://news.nationalgeographic.com/news/2001/02/0227_climate4.html">Climate Change Linked to Civilization Collapse</a> <i></i> <br> </p> </div> </td> </tr> </table> </td> </tr> </table> <br>  <table border="0" cellpadding="1" cellspacing="0" width="100%" bgcolor="black"> <tr> <td valign="middle" align="center" width="100%"> <table border="0" cellpadding="5" cellspacing="0" width="100%" bgcolor="#ffffff"> <tr>  <td bgcolor="#339999" valign="top"><div class="inline" style="margin-top: -2px;"> <font color="white"><b>Related Websites</b></font></div></td> </tr> <tr> <td valign="top" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/shadow.gif"> <div class="boxed"> <p class="inline">  <a href="https://web.archive.org/web/20021028200916/http://www.sciencemag.org/" target="_ "><i>Science</i> magazine</a> <i></i> <br> </p> </div> </td> </tr> </table> </td> </tr> </table> <br>  <p class="byline">Comments? Contact the <a href="https://web.archive.org/web/20021028200916/mailto:newsdesk@nationalgeographic.com">news desk</a>.<br></p><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" width="350" height="1" alt="" suppress="true"></td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" width="5%" valign="bottom" bgcolor="#ffffff"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="20" height="1" border="0"></td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" width="182" valign="top" bgcolor="#ffffff"><div align="right">   <script language="javaScript"> var bust; if (typeof bust == 'undefined') { bust = Math.floor(1000000*Math.random()); } document.write('<iframe width=120 height=600 marginwidth=0 marginheight=0 hspace=0 vspace=0 frameborder=0 scrolling=no bordercolor="#000000" SRC="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/adi/ng.news/newscontent;sz=120x600;tile=3;ord='+bust+'">'); document.write('<scr' + 'ipt language="JavaScript1.1" src="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/adj/ng.news/newscontent;abr=!ie;sz=120x600;tile=3;ord='+bust+'">'); document.write('</scr' + 'ipt>'); document.write('</iframe>'); </script> <noscript> <a href="https://web.archive.org/web/20021028200916/http://ad.doubleclick.net/jump/ng.news/newscontent;abr=!ie;sz=120x600"> <img width="120" height="600" border="0" src="https://web.archive.org/web/20021028200916im_/http://ad.doubleclick.net/ad/ng.news/newscontent;abr=!ie;sz=120x600;tile=3;ord=0000000"></a> </noscript>  <br><br>  <br>   <br>  <br>  <br>  <br> <br><br> <br><br> <br>   </div><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" width="182" height="1" border="0" alt=""></td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html" width="3%" valign="bottom" bgcolor="#ffffff"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="10" height="1" border="0"></td>  <td background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/nav_left.gif" width="14" valign="bottom" bgcolor="#336666"><img src="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/global/space_trans.gif" suppress="true" alt="" width="14" height="1" border="0"></td> </tr>  <tr valign="top" height="7"> <td colspan="8" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/bottom.gif" height="7"> </td> </tr> </table> <table cellpadding="0" cellspacing="0" border="0" width="100%"> <form> <tr valign="top"> <td bgcolor="#336666" background="/web/20021028200916im_/http://news.nationalgeographic.com/news/images/backgrounds/pattern.gif"> <br> <div align="center"> <p class="nav"> <a href="/web/20021028200916/http://news.nationalgeographic.com/index.html" title="nationalgeographic.com News Home.">News Home</a> </p> <p class="nav"> <a href="https://web.archive.org/web/20021028200916/mailto:newsdesk@nationalgeographic.com">Write the Editor</a> | <a href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/about/masthead.html">Masthead</a> | <a href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/community/register.html">nationalgeographic.com E-mail Updates</a> | <a href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/events/releases.html">Press Releases</a> | <a href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/community/privacy.html">Privacy Policy</a></p> <p class="nav">More to see at <b><a href="https://web.archive.org/web/20021028200916/http://www.nationalgeographic.com/" title="Adventure, travel, photography, and more.">nationalgeographic.com</a></b></p> </div> </form> <div align="center"> <p class="nav"><small>© 2002 National Geographic Society. All rights reserved.</small></p> </div><br> </td> </tr> </table>  <script language="JavaScript"> window.epulse_content_group="cg1=News,cg2=News"; </script>   <script language="JavaScript">  </script>  <script language="JavaScript" type="text/javascript" src="https://web.archive.org/web/20021028200916js_/http://magma.nationalgeographic.com/sw/ax/sw_prod_config.js"></script> <script language="JavaScript" type="text/javascript" src="https://web.archive.org/web/20021028200916js_/http://magma.nationalgeographic.com/sw/data/sw_gen_merge.js"></script> </body> </html>