Laetoli - 3.5 Million Year Old Hominin Footprints

Laetoli is the name of an archaeological site in northern Tanzania, where the footprints of three hominins--ancient human ancestors and most likely Australopithecus afarensis--were preserved in the ash fall of a volcanic eruption some 3.63-3.85 million years ago. They represent the oldest hominin footprints yet discovered on the planet.   The Laetoli footprints were discovered in 1976, eroding out of a gully of the Nagarusi river, by team members from Mary Leakeys expedition to the main Laetoli site. Local Environment Laetoli lies in the eastern branch of the Great Rift Valley of eastern Africa, near the Serengeti Plain and not far from Olduvai Gorge. Three and a half million years ago, the region was a mosaic of different ecotones: montane forests, dry and moist woodlands, wooded and unwooded grasslands, all within about 50 km (31 miles) of the footprints. Most Australopithecine sites are located within such regions--places with a wide variety of plants and animals nearby. The ash was wet when the hominins walked through it, and their soft print impressions have given scholars in-depth information about the soft tissue and gait of Australopithecines not available from skeletal material. The hominin prints are not the only footprints preserved in the wet ashfall: animals walking through the wet ash included elephants, giraffes, rhinoceroses and a wide variety of extinct mammals. In all there are 16 sites with footprints in Laetoli, the largest of which has 18,000 footprints, representing 17 different families of animals within an area of about 800 square meters (8100 square feet). Laetoli Footprint Descriptions The Laetoli hominin footprints are arranged in two 27.5 meter (89 foot) long trails, created in moist volcanic ash which later hardened because of desiccation and chemical change. Three hominin individuals are represented, called G1, G2, and G3. Apparently, G1 and G2 walked side by side, and G3 followed along behind, stepping on some but not all of the 31 footprints of G2. Based on known ratios of the length of a bipedal foot versus hip height, G1, represented by 38 footprints, was the shortest individual of the three, estimated at 1.26 meters (4.1 feet) or less in height. Individuals G2 and G3 were larger--G3 was estimated at 1.4 m (4.6 ft) tall. G2s steps were too obscured by G3s to estimate his/her height. Of the two tracks, G1s footprints are the best preserved; the track with footprints of both G2/G3 proved difficult to read, since they overlapped. A recent study (Bennett 2016) has allowed scholars to identify G3s steps apart from G2 more clearly, and reassess the hominin heights--G1 at 1.3 m (4.2 ft), G3 at 1.53 m (5 ft). Who Made Them? At least two sets of the footprints have been definitely linked to A. afarensis, because, like the fossils of afarensis, the Laetoli footprints do not indicate an opposable great toe. Further, the only hominin associated with Laetoli area at the time is A. afarensis. Some scholars have ventured to argue that the footprints are from an adult male and female (G2 and G3) and a child (G1); others say they were two males and a female. Three dimensional imaging of the tracks reported in 2016 (Bennett et al.) suggests that G1s foot had a different shape and depth of heel, a different hallux abduction and a different definition of the toes. They suggest three possible reasons; G1 is a different hominin from the other two; G1 walked at a different time from G2 and G3 when the ash was sufficiently different in texture, producing differently shaped impressions; or, the differences are a result of foot size / sexual dimorphism. In other words, G1 may have been, as others have argued, a child or a small woman of the same species. While there is some ongoing debate, most researchers believe that the Laetoli footprints show that our Australopithecine ancestors were fully bipedal, and walked in a modern manner, heel first, then toe. Although a recent study (Raichlen et al. 2008) suggests that the speed at which the footprints were made might affect the kind of gait required to make the marks; a later experimental study also led by Raichlen (2010) provides additional support for bipedalism at Laetoli. The Sadiman Volcano and Laetoli The volcanic tuff in which the footprints were made (called the Footprint Tuff or Tuff 7 at Laetoli) is a 12-15 centimeter (4.7-6 inches) thick layer of ash which fell on this region from the eruption of a nearby volcano. The hominins and a wide variety of other animals survived the eruption--their footprints in the muddy ash prove that--but which volcano erupted has not been determined. Until relatively recently, the source of the volcanic tuff was thought to be the Sadiman volcano. Sadiman, located about 20 km (14.4 mi) southeast of Laetoli, is now dormant, but was active between 4.8 and 3.3 million years ago. A recent examination of outflows from Sadiman (Zaitsev et al 2011) showed that the geology of Sadiman does not fit perfectly with the tuff at Laetoli. In 2015, Zaitsev and colleagues confirmed that it was not Sadiman and suggested that the presence of nephelinite in Tuff 7 points to the nearby Mosonic volcano, but admit that there is not conclusive proof as of yet. Preservation Issues At the time of excavation, the footprints were buried between a few cm to 27 cm (11 in) deep. After excavation, they were reburied to preserve them, but the seeds of an acacia tree was buried within the soil and several acacias grew in the region to heights of over two meters before researchers noticed. Investigation showed that although those acacia roots did disturb some of the footprints, burying the footprints was overall a good strategy and did protect much of the trackway. A new conservation technique was begun in 1994 consisting of application of a herbicide to kill all the trees and brush, the placement of biobarrier mesh to inhibit root growth and then a layer of lava boulders. A monitoring trench was installed to keep an eye on the subsurface integrity. See Agnew and colleagues for additional information on the preservation activities. Sources This glossary entry is a part of the About.com guide to Lower Paleolithic, and the Dictionary of Archaeology. Agnew N, and Demas M. 1998. Preserving the Laetoli foodprints. Scientific American 279(44-55). Barboni D. 2014. Vegetation of Northern Tanzania during the Plio-Pleistocene: A synthesis of the paleobotanical evidences from Laetoli, Olduvai, and Peninj hominin sites. Quaternary International 322–323:264-276. Bennett MR, Harris JWK, Richmond BG, Braun DR, Mbua E, Kiura P, Olago D, Kibunjia M, Omuombo C, Behrensmeyer AK et al. 2009. Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya. Science 323:1197-1201. Bennett MR, Reynolds SC, Morse SA, and Budka M. 2016. Laetoli’s lost tracks: 3D generated mean shape and missing footprints. Scientific Reports 6:21916. Crompton RH, Pataky TC, Savage R, DAoà »t K, Bennett MR, Day MH, Bates K, Morse S, and Sellers WI. 2012. Human-like external function of the foot, and fully upright gait, confirmed in the 3.66 million year old Laetoli hominin footprints by topographic statistics, experimental footprint-formation and computer simulation. Journal of The Royal Society Interface 9(69):707-719. Feibel CS, Agnew N, Latimer B, Demas M, Marshall F, Waane SAC, and Schmid P. 1995. The Laetoli Hominid footprints--A preliminary report on the conservation and scientific restudy. Evolutionary Anthropology 4(5):149-154. Johanson DC, and White TD. 1979. A systematic assessment of early African hominids. Science 203(4378):321-330. Kimbel WH, Lockwood CA, Ward CV, Leakey MG, Rak Y, and Johanson DC. 2006. Was Australopithecus anamensis ancestral to A. afarensis? A case of anagenesis in the hominin fossil record. Journal of Human Evolution 51:134-152. Leakey MD, and Hay RL. 1979. Pliocene footprints in the Laetolil Beds at Laetoli, northern Tanzania. Nature 278(5702):317-323. Raichlen DA, Gordon AD, Harcourt-Smith WEH, Foster AD, and Haas WR, Jr. 2010. Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics. PLoS ONE 5(3):e9769. Raichlen DA, Pontzer H, and Sockol MD. 2008. The Laetoli footprints and early hominin locomotor kinematics. Journal of Human Evolution 54(1):112-117. Su DF, and Harrison T. 2015. The paleoecology of the Upper Laetolil Beds, Laetoli Tanzania: A review and synthesis. Journal of African Earth Sciences 101:405-419. Tuttle RH, Webb DM, and Baksh M. 1991. Laetoli toes and Australopithecus afarensis. Human Evolution 6(3):193-200. Zaitsev AN, Spratt J, Sharygin VV, Wenzel T, Zaitseva OA, and Markl G. 2015. Mineralogy of the Laetolil Footprint Tuff: A comparison with possible volcanic sources from the Crater Highlands and Gregory Rift. Journal of African Earth Sciences 111:214-221. Zaitsev AN, Wenzel T, Spratt J, Williams TC, Strekopytov S, Sharygin VV, Petrov SV, Golovina TA, Zaitseva EO, and Markl G. 2011. Was Sadiman volcano a source for the Laetoli Footprint Tuff? Journal of Human Evolution 61(1):121-124.

Essay about The Stalinist Terror and Sofia Petrovna

In the book Sofia Petrovna, the author Lydia Chukovskaya writes about Sofia Petrovna and her dreadful experiences as a widowed mother during the Russian Stalinist Terror of the 1930s. There were four basic results of the Russian Stalinist Terror: first, it was a way of keeping people in order; second, it kept Stalin in power and stopped revolutions from forming, made people work harder to increase the output of the economy, and separated families as well as caused deaths of many innocent people due to false charges. Stalin used the media in order to convince the Russian citizens that there were saboteurs and spies within Russian population. Stalin used the secret police and military forces to carry out the arrests of so called†¦show more content†¦The media also expresses that the imprisonment of the spies is the right thing to do. Up with the banner of Bolshevik vigilance, as we are taught by the genius of the leader of the peoples, comrade Stalin! Let us root out all saboteurs, secret and open, and all those in sympathy with them(83) As Sofia Petrovna reads the Timofeyev editorial, her boss, Timofeyev, is accusing Sofia for being a saboteur because she had sympathy for Natasha being fired, another so called saboteur. Stalin and his mass media propaganda persuade Timofeyev into taking part in the terror, resulting Timoteyevs belief that what Stalin is doing is the best for the Russian country. The terror stopped revolutions from forming because whatever groups Stalin didnt agree wit h he could simply arrest the members of that group. In Timofeyevs editorial Sofia is siding with a Natasha, Natasha is thought to be a revolutionary, because Natasha wasnt said to be loyal to the communist regime, and therefore Sofia is accused of siding with a sabotager or revolutionary. The terror also kept people working harder to increase the output of the economy. Movements such as the Stakhanovite movement, squeezed greater efforts out of workers and those who fell behind usually were accused of sabotaging. This benefited the Russian economy as they attempted to catch up to Europe and America throughout the age of

American Born Chinese free essay sample

In American Born Chinese by Gene Luen Yang, the main theme would have to be identity. Despite the graphic novel consisting of three separate storylines, the main characters in the book all share the same issue being uncomfortable with whom they are and connected to. If one were to simplify and boil the message of the book down to one word, it would be self-acceptance. The morals of identity and self- acceptance are what American Born Chinese is about. Yangs novel serves as a reminder that we must accept ourselves how we are not trying to be something or someone we are not. In the first storyline of the novel, the readers are introduced to the legendary Monkey King the first of three characters who struggle with self-acceptance. Even though he reigns over Flower Mountain, Monkey is not content by being Just a king he desires to be recognized as a deity. We will write a custom essay sample on American Born Chinese or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Nevertheless, because other deities see him nothing other than a monkey, he learns as many disciplines as possible to exceed the life of his kind. However, in the end, attempting to be something he is not, he loses control. The second storyline brings in Jin Wang, a young kid who is enrolled in an American school after coming from China. Not long after his first day of school, Jin finds out Just how difficult it is to be one of the few Asians among the many American faces. Afterwards, when another young boy from Taiwan is enrolled as an exchange student named Wei-Chen, Jin at first takes no interest. He doesnt want to be out in public with other Asian people, but he later realizes the things they have in common and later become the best of friends. In spite of that though, Jin Wang is internally ashamed of his friends Asian heritage. The last storyline presents Danny, an American high school basketball player who has the perfect student life every year until his cousin from China, Chin-Kee, comes for a visit. Just when Danny is about to get a girlfriend, make a sports team, or become popular around school, a visit from his F. O. B. cousin changes his whole life, forcing Danny to transfer schools in order to escape the embarrassment and shame. Because Chin-Kee has slanted eyes, buck teeth, knows Kung-Fu, and has an accent, Danny loses his way and goes all out on his cousin only resulting in one very bad In the end, all three storylines merge together, revealing the moral of the novel accepting yourself Just the way you are. Each character was ashamed of something they were unfortunately connected to the Monkey Kings species, Jins Asian culture, and Dannys cousin. They were so obsessed with how others saw them that they lost control, bringing harm only to themselves. The Monkey King, Jin, and Danny all at first failed to realize that there is nothing wrong with being an outsider. This novel, all in all, stresses the importance of self-acceptance.