BIOL_1500 - 4

.pdf

School

University of Guelph *

*We aren’t endorsed by this school

Course

1500

Subject

Anthropology

Date

Oct 30, 2023

Type

pdf

Pages

Uploaded by ssmf22dr

NOTES Evolutionary History of Humans - Human evolution is arguably one of the most fascinating topics in science. Inevitably, the topic of when we evolved and why human groups differ gets linked to the concept of race - In order to obtain some understanding as to the origins of apelike-to-human-like species, known as hominins, trace back 6 million years to Africa, where the upright walking hominins lived - Evidence of tool making is recorded 2.5 million years ago - Two million years ago, early ancestors of hominids migrated from Africa to Asia (Hublin, 2014) - Over time, and with climate changes, some hominids groups were able to adapt and survive - Hominids appear to have branched into different species - Around 200 thousand years around, evidence of increased brain size can be observed in fossil remains - One can observe the ape-like features present in the ancient hominins (dating back 3.5 – 2.0 million years ago) - The large snout; protruding jaw, small braincase and receding forehead are features present in these ancient hominins - Notice the transition from ancient hominins to modern hominins, from small to larger brain case; from protruding brows to a flatter facial area; and from a protruding jaw to a reduced jaw size, present in the modern hominin - Modern human-like hominids continued to spread around the world, although many early hominid forms became extinct (Hublin, 2014). - - Dr. Rick Potts (SINMNH 2011a) presents the evidence of evolution (involving change over time) by means of both a change in physical form, and a change in behaviour - The change in physical form was the change to a large braincase and small face from earlier forms

- A change in behaviour can be seen in the progression from stone flakes (2.5 million years ago), to a hand axe (1.5 million years ago), a refined hand axe and innovation of arrowheads (0.5 million years ago) and finally bone harpoons, symbolic markings on bones, antlers, etc., language to communicate with each other, and art on cave walls (100,000 years ago). - Homo erectus slowly expanded its range out of Africa - It provides a visual on where the early hominins migrated to, and displays the different environments that these early groups may have encountered - It portrays the first of the many great migration expansions of our ancestors - Climate shifts (i.e. hot -cold; moist – dry) would have influenced the type of food and material available to early hominids - Climate instability may have triggered adaptations, some of which may have allowed certain hominid forms to survive - Along with walking upright and making tools, hominids would have developed other skills and adaptations such as working with hands, communicating and communication with symbols. - This is an example of how new fossil evidence changes our thinking about human evolution - Fossil remains of an early hominin from the late Pleistocene were discovered in an isolated island, Flores, in Indonesia (Brown et al. 2004) - The fossil Homo florensiensis was nicknamed “the Hobbit” because of its short stature. - Dr. Matt Tocheri (SINMNH 2011 d) explains why the little hominin, who lived about 18,000 years ago, is of great interest to paleoanthropologists and evolutionists - The fossil skeleton’s proportions differ from modern humans in height; its short legs; and in wrist bones (SINMNH 2011 d) - Of interest is the wrist structure in “the hobbit” which differs from the modern hominins (i.e. Neanderthals and Homo sapiens ) and is similar to an earlier hominin species - However, this species lived at the same time as Homo sapiens ! Thus, these “hobbits” appear to have a different lineage than Homo sapiens and the Neanderthals. - One of the main things you should be aware of is the relatively small number of fossils upon which the human origin hypotheses are based - This reminds us that the evolutionary sequences of events that gave rise to humans can really be thought of as a set of scientific hypotheses. - Scientists are still are discovering fossils, and the current hypotheses of hominin evolution, may change with new discoveries - This is how science works. Scientific hypotheses may be modified or even refuted based on new evidence.

Your preview ends here

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