Mites that feed on llama poop may track the rise and fall

first_img iStock.com/OGphoto Email Mites that feed on llama poop may track the rise and fall of the Incan Empire By Lizzie WadeJan. 8, 2019 , 9:50 AM The history of the Andes might well be written in llama poop. Researchers have found that in a small, dried-up lake in highland Peru, mites that ate these creatures’ feces closely track major historical events through their population growth, including the rise and fall of the Incan Empire. In certain kinds of environments, this new method of peering back in time might be more accurate than another common one: using dung-dwelling fungal spores to track environmental conditions in the past.The ancient lake in question, called Marcacocha, is now a wetland high in the Andes, near the Incan city of Ollantaytambo. But before it disappeared about 200 years ago, it was a small pool surrounded by grassland and a popular stop for Incan llama caravans. Thousands of llamas carrying trade goods such as salt and coca leaves marched through the basin, drank from the lake, and defecated en masse. That dung washed into the lake, where it was eaten by oribatid mites, a half-millimeter-long spider relative that lived in the lake.The more llamas that passed through Marcacocha, the more poop the mites had to eat, and the larger their populations could grow. When the mites died, they sank into the lake mud, preserved where Alex Chepstow-Lusty, a paleoecologist at the University of Sussex in Brighton, U.K., found them in a sediment core centuries later. Sign up for our daily newsletter Get more great content like this delivered right to you! Countrycenter_img Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe Click to view the privacy policy. Required fields are indicated by an asterisk (*) When Chepstow-Lusty counted the number of mites in each layer of the core, he found that their population boomed when the Incan Empire dominated the Andes from 1438 C.E. to 1533 C.E. But after the Spanish arrived, the number of mites in the core plummeted. That’s because so many of the Indigenous people and their animals died during and after the conquest of the empire, Chepstow-Lusty says. Although the mite population rose again once European cows and pigs moved in and started to poop around the lake, it dropped off around 1720 C.E., when a smallpox epidemic swept through the area.Intrigued by the mite record, Chepstow-Lusty decided to see what another poop-eating microorganism could tell him. The spores of a fungus called Sporormiella live on herbivore dung and are often used to track past populations of large plant eaters, including ice age giants like mastodons and mammoths. An abrupt drop-off in Sporormiella spores is often interpreted as a sign of when those animals went extinct.Chepstow-Lusty saw the Sporormiella population rise and fall in the Marcacocha core. But those cycles didn’t track with the mite population or the known historical events that led to llama die-offs. Rather, the spores boomed during dry periods, when the lake got smaller and the llamas were able to poop closer to its center (the eventual source of the sediment core) and shrank when the lake was bigger, the team reports today in The Journal of Archaeological Science. For certain kinds of small, shallow lakes like Marcacocha, therefore, the Sporormiella record might offer misleading information about past herbivore populations.Mark Bush, a paleoecologist at the Florida Institute of Technology in Melbourne, agrees that the environment of Marcacocha doesn’t lend itself to Sporormiella studies. Although the mites “provide an interesting alternative,” he says, there haven’t been enough studies in other places testing the relationship between the numbers of mites and the size of herbivore populations to be sure the mites are truly an accurate proxy.Chepstow-Lusty hopes other researchers will start to tally up oribatid mites in their sediment cores, in hopes of figuring out when and where they may offer accurate information beyond Marcacocha. “You never know what you’re going to find in your lake muds,” he says. All microorganisms—especially the poop-eating ones—deserve a closer look. Andean llamas at Machu Picchu in Perulast_img

Leave a Comment

Your email address will not be published. Required fields are marked *