Lab 9: The Australopithecines and Early Members of the Genus Homo

pdf

School

Napa Valley College *

*We aren’t endorsed by this school

Course

122

Subject

Anthropology

Date

Dec 6, 2023

Type

pdf

Pages

Uploaded by KidFang5056

Liliana Fregoso Lab 9: The Australopithecines and Early Members of the Genus Homo • Concept review questions 1 – 10 1. As a group, the australopiths lived around: 4 mya to 1 mya. 2. The fossil individual nicknamed Lucy was: a habitual biped. 3. Name two eastern African australopiths.Au Anamensis and afarensis 4. Name two southern African australopiths. Au africanus and robustus 5. The oldest australopith is: Australopithecus anamensis. 6. Describe the two primary tool types associated with the Oldowan technology. Homonin of age 2.6 to 1.5 million year old created these tools. The tools associated with oldowan technology were basically chips cut out of rocks such as obsidian, basalt etc. Rocks and minerals with conchoidal fracture and that showing chip were used. Quartz, Basalt, Obsidian, Quartzite etc was used. Basically rocks that hold edges were used. Tools made out of them were divided into heavy duty, light duty, waste The tools made were named as 1) Cores: spheroid, discoids and polyhedron shaped 2) Scrapers 3) Choppers 7. Based on recent evidence from the eastern African sites of Lomekwi (Kenya), Dikika (Ethiopia), and Gona (Ethiopia), which of these species may be among the first stone tool users? Australopithecus garhi 8. Some researchers argue that the robust australopiths should be classified in a separate genus. What is that genus called? Paranthropus 9. I lived around 2.5 mya in eastern Africa. I had a small cranial capacity (around 410 cc), large molars, large zygomatic arches, and a sagittal crest. What species am I? Australopithecus (Paranthropus) aethiopicus

10. Describe one feature that decreases in size between the australopiths and early members of the Homo genus. Teeth size and zygomatic arch. Exercises 1, 3, 5 Exercise 1: 1. Which of the mystery specimens is a human? What evidence indicates this?A represent mandible and dentition of humans. Evidence:Humans have small molars and chewing muscles compared to robust australopithecines. In modern humans there is a reduction in canine size, the front lower premolar tooth is bicuspid and the gap between teeth on the mandible. They have small jaws. 2.Which of the mystery specimens is a gracile australopith? What evidence indicates this? C represents mandible and dentition of gracile australopith. Evidence:Gracile australopith had less exaggerated, smaller and less robust features like the absence of sagittal crest and less flared cheeks. They had relatively larger incisors and canines and smaller premolars and molars. 3. Which of the mystery specimens is a robust australopith? What evidence indicates this?B represents mandible and dentition of robust australopith. Evidence:They had large posterior dentitions, thick enamel and large chewing muscles. The presence of a sagittal crest and flared cheeks, large jaws. They had relatively smaller incisors and canines and larger premolars and molars. Exercise 3: 1. Examine the Lucy (Australopithecus afarensis) skeleton. Describe at least two postcranial (below the head) traits that indicate that Au. afarensis was adapted for bipedalism.Postcranial traits that show that Au. afarensis was adapted for bipedalism are :-a) The iliac blade is

short and wide, and sacrum is wide and placed directly behind the hip joint.b) Strong attachments for knee extensors were also present. 2. Compare Lucy (Au. afarensis) skeleton with the human (Homo sapiens) skeleton. Describe at least two postcranial traits that differ between these species. Postcranial traits that differ between the two species are :- a) The femoral head is small, and the femoral neck is short, which differs from modern day species. The length ratio of humerus to femur is 84.6% and that of modern species is 71.8%. The acetabulum in the pelvic girdle is small and primitive. b) Rib cage is similar to the conical rib cage of non-human great apes of modern days. 3. What do your answers suggest about the kind of bipedalism practiced by Au. afarensis? It followed a habitual bipedalism because it walked upright straight and its features were developed for walking too, but also it was an arboreal too. Exercise 5: 1. Describe at least two traits that differ between these fossils. (Be sure to describe how each trait appears in the two fossils.) The two traits differing in the given fossil and which can be seen clearly are as follows:-1. The Homos has reduced prognathism i.e. they have a flatter face and a shorter tooth row in comparison to that of Australopiths. Australiopitho have protruded face broader teeth. 2. The Homos possesses a greater cranial capacity, which is attributed to its large brain size than that of Australiopitho which can be clearly seen in the given fossil. Even the broca area and forehead is more bulged in homos. 2. Based on this information, which of these fossils is an australopith? Mystery Specimen B 3. Based on this information, which of these fossils is a member of the Homo genus? Mystery Specimen A

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

mystery specimen A is a member of genus Homo and mystery specimen B is a member of genus Australopitho. As it can be seen in the given source image and based on the differences mentioned in the above answer we can surely say which skull belongs to which species. specimen B have more ape like face and they have lower forehead protruding mouth. • Critical thinking questions 1, 3, 4 1. What do you think is the best way to classify the robust species of australopiths? Do you support the use of the genus Paranthropus? Why or why not? (Be sure to support your decision with specific evidence.)The One approach to categorizing the robust australopithecines is to leave them categorized as they are.In contrast, the second is to assign them into their own group, the Paranthropus, because of the disparities they have from the rest. I believe it could be effective to set them into their own category to assist fill in more of the vacant areas we possess in our history. However, it would perhaps be best to wait until more fossils are found to establish that they require their own category. 3. In this lab, we discussed the earliest known stone tools. Do you think those tools represent the first time our extinct relatives used tools? Why might older tools not be preserved in the fossil record? For comparison, describe three tools from your own life (for example, a cell phone, a pencil, and a plastic fork). Do you think these tools will be preserved 2.5 million years from today? I think there were more early stone tools used by our ancestors. Either these stone tools yet to be discovered or may not have fossilized due to devoid of necessary fossilization condition.For the fossilization of any biologic item or any instruments or tools, there must be some necessary conditions such asi) There should be quickly burying of material before it's decaying,ii) The item should be hard (in general) and not soft in nature such as bone, stones, shells, metals etc.iii) The burying of item should be in calcium or carbonate

reached (in limestone) geologic environment to be better preserved.If these necessary conditions, do not fulfill then the fossilization of any items do not occur in general.Thus, there would be some other part of the area which may contain more ancient stone tools than we have found till today. These tools may be discovered in future years. Or, it is also possible that the earliest stone tools were not fossilized because of not fulfilling the conditions for fossilization.Now, in comparison to current aged tools such as mobile phones, plastic forks. These two items may get fossilized on the bottom of the sea because these items do not decay easily and also has chance to transported to deeper oceanic area via rivers or by the people who often goes to ocean beach and sometimes drop their mobile phones and frequently throw plastic forks on the ocean.Whereas pencil is made of wood and a soft lead, which is a biodegradable and quickly decay within few months of being into Earth surface. Thus, pencil has very less chance of fossilization but other two items may be fossilized which may be found as a fossil after 2.5 years from now. 4. During a period of almost a million years, Australopithecus boisei and Homo habilis lived in the same region of eastern Africa. If these species shared a habitat, why didn’t one of them outcompete the other? (Hint:Think about their possible ecologies and adaptations.) Australopithecus boisei or Paranthropus boisei was an early hominin that lived in Africa about 1.2 million years ago. It is described as the largest of the Paranthropus genus. Homo habilis was a species of the Hominini, during stages of the Pleistocene period, about 1.5 million years ago. Though Australopithecus boisei and homo habilis lived in the same region of east Africa and shared a habitat they did not outcompete each other. This may be due to resource partitioning and interspecific competition.If similar species occupy the same geographic area, they divide a niche to avoid competition for resources, which is termed as resource partitioning. In this way, these species occupy different portions of the habitat, or utilize different resources or food thus avoiding competition. This competition between species where both are benefited is called interspecific

competition.During the course of time, one species did not cause extinction of other species due to niche differentiation. Niche differentiation helped both the species to coexist together by using the environment differently.

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

Lab 9: The Australopithecines and Early Members of the Genus Homo

Related Documents