4-2 Final Project Milestone 2

docx

School

Southern New Hampshire University *

*We aren’t endorsed by this school

Course

210

Subject

Anthropology

Date

Jan 9, 2024

Type

docx

Pages

Uploaded by EarlNarwhalPerson768

Hominin Evolution For this portion of the exhibit, I would recommend the museum showcase Sahelantrhopus Tchadensis, Ardipithacus Ramidus, Australopithecus afarensis and Homo Erectus. These fossils could all serve as key representatives that illustrate the progression of adaptations that occurred over millions of years. Additionally, the discovery sites of these hominins reveal the geographical distribution of our ancestors and their ability to survive and adapt to varied environments across Africa and beyond. Sahelanthropus Tchadensis Sahelanthropus Tchadensis, discovered in Chad in 2001, is the oldest known hominin, living between 7 and 6 million years ago (SNMNH, 2022d). This early hominin possesses a mix of ancestral and derived traits. Its robust skull has a prominent brow ridge and a brain capacity similar to that of modern chimpanzees, while also featuring smaller canine teeth, reduced prognathism and an indication of possible bipedalism (Boyd & Silk, 2021). While no post cranial remains have been found, the foramen magnum is located under the skull (as it is in modern humans) indicating that the head of s. tchadensis likely sat on an upright body (SNMNH, 2022d). Prior to its discovery, early hominins in Africa had only been found in the east and south of the continent, as such, the discovery in Chad widened the geographic spread of hominins across Africa 7 mya. Ardipithecus Ramidus Another important chapter in the story of human evolution is Ardipithecus ramidus, a hominin that lived between 4.5 and 4.2mya and was discovered west of the Awash River, in Aramis, Ethiopia. Like S. tchadensis, Ar. ramidus exhibits a mix of ancestral and derived traits. While the pelvis and leg bones are indicative of bipedalism, ancestral traits indicate that this hominin climbed trees efficiently, specifically exhibiting a high intermembral index, long curved finger bones and opposable big toes (Taylor & Welker, 2017). Additional ancestral traits include a cranial capacity of 300-350 cc and a U-shaped dental arcade. By examining this combination of

2 HOMININ EVOLUTION ancestral and derived traits we can speculate that Ar. ramidus was able to walk upright on the ground and also climb trees- moving quadrupedally along the branches, using their palms to support their weight (Dorey, 2018). Australopithecus Afarensis Australopithecus afarensis, one of the longest living hominins, lived between 3.9 and 2.8 mya in eastern Africa. This species is represented by several hundred fossils, including an almost complete female skeleton (nicknamed Lucy), a group of fossils composed of nine adults and four children (commonly referred to as “the first family”), and a set of fossilized bipedal footprints (Dorey, 2021). The ancestral and derived features of this species enabled it to survive for more than 900,000 years as the climate and environment changed (SNMNH, 2022b). Curved finger bones, a high intermembral index and ape like shoulder anatomy aided Au. afarensis in climbing trees while their somewhat bowl-shaped pelvis, arched feet and the angle of their femurs are all indicative of more efficient bipedalism than it predecessors (Taylor & Welker, 2017). Additionally, while Au. afarensis’ cranial capacity is significantly smaller than that of modern humans, it is 20% larger than that of modern chimpanzees, illustrating the beginning of the trend towards larger brains seen in later hominins (Pavid, 2020). Finally, fossil remains discovered in Ethiopia, Kenya, and Tanzania illustrate a geographic range of almost 1,000 miles (the distance between discovery sites in Ethiopia and Tanzania), emphasizing a widespread presence of this hominin across Africa. Homo Erectus Homo erectus, an extinct member of our genus, appears in the African fossil record about 1.9 mya. Unlike earlier hominins whose geographic range was limited to regions of Africa, this species inhabited a wide variety of habitats, with evidence of Homo eretus having been found across the entire continent of Africa, expanding into western and eastern Asia by 1.8-1.6 mya (Boyd & Silk, 2021). In addition to geographic expansion, this species marks an incredible moment in the overall story of human evolution as its cranial capacity increased over time, reaching 1000cc by 1 mya, a significant increase in size compared to earlier hominins. Their post

3 HOMININ EVOLUTION cranial morphology was more like that of modern humans, possessing longer legs and shorter arms relative to its torso and the loss of shoulder morphology necessary for climbing trees, indicating that homo erectus’ lives were likely exclusively terrestrial, just like modern humans (Hendry, n.d.). Biological Variation Determining the degree of variation among and within groups of the above-mentioned hominins can be challenging due to the fragmentary nature of the fossil record. However, trends in biological variation, such as adaptations related to locomotion and overall morphology are identifiable and depict how hominins diversified and adapted to various environments over millions of years. While we are not able to determine skin color via the fossil record, we can speculate that like modern humans living in diverse environments, early hominins likely varied in skin color depending on their habitat, with the evolution of depigmented skin occurring as early humans dispersed into environments further from the equator (Jablonski & Chaplin, 2017). Ethical Considerations Because displaying these fossils is an important part of the educational aspect of the museum exhibit, it is paramount that museum staff obtain these fossils ethically. They must make sure they are not purchasing from sellers who obtain specimens via the black market or other seedy means, perhaps instead relying on partnerships with universities, purchasing from donations from private collections, and compensating archaeologists for their findings, perhaps by providing funding for further research. Additionally, museum staff may elect to display replicas of fossils when obtaining originals proves to be challenging due to limited availability or an inability to obtain them ethically. These replicas, while perhaps not as impressive as originals, can provide museum visitors with a hand on experience that they otherwise would not be able to have while also giving them a better understanding of the size, shape, and overall morphology of our ancestors.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

4 HOMININ EVOLUTION References: Boyd, Robert, and Joan B. Silk. How Humans Evolved. Available from: VitalSource Bookshelf, (9th Edition). W. W. Norton, 2021. Dorey, F. (2018, April 14). Ardipithecus Ramidus . The Australian Museum. https://australian.museum/learn/science/human-evolution/ardipithecus-ramidus/ Hendry, L. (n.d.). Homo erectus, our ancient ancestor . Natural History Museum. https://www.nhm.ac.uk/discover/homo-erectus-our-ancient-ancestor.html MacDonald, J. (2017, November 3). The popular, lucrative, and legally questionable fossil trade . JSTOR. https://daily.jstor.org/the-popular-but-legally-questionable-fossil-trade/ Pavid, K. (2020, April 1). Australopithecus afarensis: Human ancestors had slow-growing brains just like Us . Natural History Museum. https://www.nhm.ac.uk/discover/news/2020/april/australopithecus-afarensis-had-slow- growing-brains.html Smithsonian National Museum of Natural History. (2022a, June 30). Ardipithecus ramidus . The Smithsonian Institution’s Human Origins Program. https://humanorigins.si.edu/evidence/human-fossils/species/ardipithecus-ramidus Smithsonian National Museum of Natural History. (2022b, June 30). Australopithecus afarensis . The Smithsonian Institution’s Human Origins Program. https://humanorigins.si.edu/evidence/human-fossils/species/australopithecus-afarensis Smithsonian National Museum of Natural History. (2022c, June 30). Homo erectus . The Smithsonian Institution’s Human Origins Program. https://humanorigins.si.edu/evidence/human-fossils/species/homo-erectus Smithsonian National Museum of Natural History. (2022d, July 7). Sahelanthropus tchadensis . The Smithsonian Institution’s Human Origins Program. https://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis Straight, T. (2023, November 3). Ohio students get hands-on experience with fossil replicas . Ohio University- Student News. https://www.ohio.edu/news/2023/11/ohio-students-get- hands-experience-fossil-replicas

5 HOMININ EVOLUTION Taylor, I. by K., & Welker, B. H. (2017, June 13). The history of our tribe: Hominini . The History of Our Tribe Hominini. https://milnepublishing.geneseo.edu/the-history-of-our- tribe-hominini/

4-2 Final Project Milestone 2

Related Documents