{"id":19203,"date":"2020-09-17T16:27:20","date_gmt":"2020-09-17T10:42:20","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=19203"},"modified":"2020-09-17T17:04:21","modified_gmt":"2020-09-17T11:19:21","slug":"did-our-early-ancestors-boil-their-food-in-hot-springs","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/did-our-early-ancestors-boil-their-food-in-hot-springs\/","title":{"rendered":"Did our early ancestors boil their food in hot springs?"},"content":{"rendered":"\n

Scientists have found evidence of hot springs near sites where ancient hominids settled, long before the control of fire.<\/em><\/strong><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

CAMBRIDGE, Mass.(MITNews office) –Some of the oldest remains of early human ancestors have been unearthed in Olduvai Gorge, a rift valley setting in northern Tanzania where anthropologists have discovered fossils of hominids that existed 1.8 million years ago. The region has preserved many fossils and stone tools, indicating that early humans settled and hunted there.<\/p>\n\n\n\n

Now a team led by researchers at MIT and the University of Alcal\u00e1 in Spain has discovered evidence that hot springs may have existed in Olduvai Gorge around that time, near early human archaeological sites. The proximity of these hydrothermal features raises the possibility that early humans could have used hot springs as a cooking resource, for instance to boil fresh kills, long before humans are thought to have used fire as a controlled source for cooking.<\/p>\n\n\n\n

\u201cAs far as we can tell, this is the first time researchers have put forth concrete evidence for the possibility that people were using hydrothermal environments as a resource, where animals would\u2019ve been gathering, and where the potential to cook was available,\u201d says Roger Summons, the Schlumberger Professor of Geobiology in MIT\u2019s Department of Earth, Atmospheric, and Planetary Sciences (EAPS).  <\/p>\n\n\n\n

Summons and his colleagues have published their findings today in the Proceedings of the National Academy of Sciences<\/em>. The study\u2019s lead author is Ainara Sistiaga, a Marie Sk\u0142odowska-Curie fellow based at MIT and the University of Copenhagen. The team includes Fatima Husain, a graduate student in EAPS, along with archaeologists, geologists, and geochemists from the University of Alcal\u00e1 and the University of Valladolid, in Spain; the University of Dar es Salaam, in Tanzania; and Pennsylvania State University.<\/p>\n\n\n\n

An unexpected reconstruction<\/strong><\/p>\n\n\n\n

In 2016, Sistiaga joined an archaeological expedition  to Olduvai Gorge, where researchers with the Olduvai Paleoanthropology and Paleoecology Project were collecting sediments from a 3-kilometer-long layer of exposed rock that was deposited around 1.7 million years ago. This geologic layer was striking because its sandy composition was markedly different from the dark clay layer just below, which was deposited 1.8 million years ago.<\/p>\n\n\n\n

\u201cSomething was changing in the environment, so we wanted to understand what happened and how that impacted humans,\u201d says Sistiaga, who had originally planned to analyze the sediments to see how the landscape changed in response to climate and how these changes may have affected the way early humans lived in the region.<\/p>\n\n\n\n

It\u2019s thought that around 1.7 million years ago, East Africa underwent a gradual aridification, moving from a wetter, tree-populated climate to dryer, grassier terrain. Sistiaga brought back sandy rocks collected from the Olduvai Gorge layer and began to analyze them in Summons\u2019 lab for signs of certain lipids that can contain residue of leaf waxes, offering clues to the kind of vegetation present at the time.<\/p>\n\n\n\n

\u201cYou can reconstruct something about the plants that were there by the carbon numbers and the isotopes, and that\u2019s what our lab specializes in, and why Ainara was doing it in our lab,\u201d Summons says. \u201cBut then she discovered other classes of compounds that were totally unexpected.\u201d<\/p>\n\n\n\n

An unambiguous sign<\/strong><\/p>\n\n\n\n

Within the sediments she brought back, Sistiaga came across lipids that looked completely different from the plant-derived lipids she knew. She took the data to Summons, who realized that they were a close match with lipids produced not by plants, but by specific groups of bacteria that he and his colleagues had reported on, in a completely different context, nearly 20 years ago.<\/p>\n\n\n\n

The lipids that Sistiaga extracted from sediments deposited 1.7 million years ago in Tanzania were the same lipids that are produced by a modern bacteria that Summons and his colleagues previously studied in the United States, in the hot springs of Yellowstone National Park.<\/p>\n\n\n\n

One specific bacterium, Thermocrinis ruber<\/em>, is a hyperthermophilic organism that will only thrive in very hot waters, such as those found in the outflow channels of boiling hot springs.<\/p>\n\n\n\n

\u201cThey won\u2019t even grow unless the temperature is above 80 degrees Celsius [176 degrees Fahrenheit],\u201d Summons says. \u201cSome of the samples Ainara brought back from this sandy layer in Olduvai Gorge had these same assemblages of bacterial lipids that we think are unambiguously indicative of high-temperature water.\u201d<\/p>\n\n\n\n

That is, it appears that heat-loving bacteria similar to those Summons had worked on more than 20 years ago in Yellowstone may also have lived in Olduvai Gorge 1.7 million years ago. By extension, the team proposes, high-temperature features such as hot springs and hydrothermal waters could also have been present.<\/p>\n\n\n\n

\u201cIt\u2019s not a crazy idea that, with all this tectonic activity in the middle of the rift system, there could have been extrusion of hydrothermal fluids,\u201d notes Sistiaga, who says that Olduvai Gorge is a geologically active tectonic region that has upheaved volcanoes over millions of years \u2014 activity that could also have boiled up groundwater to form hot springs at the surface.<\/p>\n\n\n\n

The region where the team collected the sediments is adjacent to sites of early human habitation featuring stone tools, along with animal bones. It is possible, then, that nearby hot springs may have enabled hominins to cook food such as meat and certain tough tubers and roots.<\/p>\n\n\n\n

 \u201cWhy wouldn\u2019t you eat it?\u201d<\/strong><\/p>\n\n\n\n

Exactly how early humans may have cooked with hot springs is still an open question. They could have butchered animals and dipped the meat in hot springs to make them more palatable. In a similar way, they could have boiled roots and tubers, much like cooking raw potatoes, to make them more easily digestible. Animals could have also met their demise while falling into the hydrothermal waters, where early humans could have fished them out as a precooked meal.<\/p>\n\n\n\n

\u201cIf there was a wildebeest that fell into the water and was cooked, why wouldn\u2019t you eat it?\u201d Sistiaga poses.<\/p>\n\n\n\n

While there is currently no sure-fire way to establish whether early humans indeed used hot springs to cook, the team plans to look for similar lipids, and signs of hydrothermal reservoirs, in other layers and locations throughout Olduvai Gorge, as well as near other sites in the world where human settlements have been found.<\/p>\n\n\n\n

\u201cWe can prove in other sites that maybe hot springs were present, but we would still lack evidence of how humans interacted with them. That\u2019s a question of behavior, and understanding the behavior of extinct species almost 2 million years ago is very difficult, Sistiaga says. \u201cI hope we can find other evidence that supports at least the presence of this resource in other important sites for human evolution.\u201d<\/p>\n\n\n\n

This research was supported, in part, by the European Commission (MSCA-GF), the NASA Astrobiology Institute, and the Government of Spain.<\/p>\n","protected":false},"excerpt":{"rendered":"

Some of the oldest remains of early human ancestors have been unearthed in Olduvai Gorge, a rift valley setting in northern Tanzania where anthropologists have discovered fossils of hominids that existed 1.8 million years ago. <\/p>\n","protected":false},"author":2,"featured_media":19204,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-19203","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",900,600,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking-200x200.jpg",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking-600x400.jpg",600,400,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking-768x512.jpg",750,500,true],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking-675x450.jpg",675,450,true],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",900,600,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",900,600,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",900,600,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",855,570,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",600,400,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",600,400,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking-760x490.jpg",760,490,true],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking-550x360.jpg",550,360,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking-95x65.jpg",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",640,427,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",96,64,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2020\/09\/Hydrothermal-Cooking.jpg",150,100,false]},"author_info":{"info":["RevoScience"]},"category_info":"Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/19203","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=19203"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/19203\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/19204"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=19203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=19203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=19203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}