Week 4 Archaeology
Weekly Topics and subtopics
Basic Overview of Paleoanthropology
Our understanding of human origins is based on evidence. Available sources can be broken into two general categories: evidence from the living world (biology, including genetics, of living organisms) and evidence from the past (geology, paleontology, and paleoanthropology). The rare fossilized components of the past form an essential empirical anchor for understanding the course of our evolution after the split from the chimpanzee/bonobo lineage. The remains are limited to those preserved and later presented via geological processes. As of the early 21st Century, the human fossil and archaeological record is vast, and understanding it as a simple narrative is impossible. The only way to approach it is to understand know all of the hundreds of sites and thusands of fossils, a relatively intensive endeavor.
Site-based, Localized, and Young
The science of human origins is more historical than most. While most of the physical evidence documenting the reality of evolution- animal bodies and geographic distributions, developmental programs, DNA- comes from the modern world, these lines of evidence do not allow us to see all of the forms, the evolutionary twists and turns, in the paths from the origin of life to its present pattern. This is where paleontology comes in.
For example, knowing that humans and chimps are each other's most recent common ancestors, we can speculate that as we go back in time along the lineage we should get progressively more chimp-like and chimps more like us. But which changes happened first? Did everything happen at once? Did the changes happen early or late in the game? These types of questions can only be answered by seeing into the past, and this is done with the fossil record. The endless processes of tectonic drift and uplift, combined with the similarly incessant rain and erosion cycle, have resulted in countless layers of sediment, many of which have been hardened with pressure and heat. Many animals and plants got caught up in the deposition and preserved. The record is complete enough that it is possible to propose hypotheses and then try to address them with evidence from the fossil record, but, this said, it is not complete enough that it provides answers for every question one might ask, even some of the most interesting ones.
For this reason, students of paleoanthropology themselves usually evolve during the course of study, moving from trying to address the most salient questions about human existence to addressing what you can actually detect in the fossil record. The difference is dramatic, and it can be a bit of a turn-off when you start to see how many people incredulously evoke the human fossil record when trying to answer a burning, but unanswerable, question. In paleoanthropology, the difference between what we know concretely to have existed and what could possibly have existed given the scraps of evidence we have is sublime. The teacher who keeps to the facts is dry and boring to most, and the one who embellishes is interesting to the uninformed majority. It is a shame, but, as with all knowledge, beauase learning is active it is ultimately the responsibility of the learner. It turns out that the only way you can really overcome bias is to learn the record for yourself, but it is vast. Many sites are small and have only yielded a few specimens, sometimes with no date at all. Some sites are large, well-dated, and serve as major datapoints. Every site has a different history of discovery, political history, and history of people working there. Additionally, the ENTIRE human fossil record has been compiled in just under 200 years. Things have grown quite rapidly and chaotically. So the experimental lab is quite different from that of a chemist or physicist. The next links allow you to get a sense of how vast the record is.
For example, knowing that humans and chimps are each other's most recent common ancestors, we can speculate that as we go back in time along the lineage we should get progressively more chimp-like and chimps more like us. But which changes happened first? Did everything happen at once? Did the changes happen early or late in the game? These types of questions can only be answered by seeing into the past, and this is done with the fossil record. The endless processes of tectonic drift and uplift, combined with the similarly incessant rain and erosion cycle, have resulted in countless layers of sediment, many of which have been hardened with pressure and heat. Many animals and plants got caught up in the deposition and preserved. The record is complete enough that it is possible to propose hypotheses and then try to address them with evidence from the fossil record, but, this said, it is not complete enough that it provides answers for every question one might ask, even some of the most interesting ones.
For this reason, students of paleoanthropology themselves usually evolve during the course of study, moving from trying to address the most salient questions about human existence to addressing what you can actually detect in the fossil record. The difference is dramatic, and it can be a bit of a turn-off when you start to see how many people incredulously evoke the human fossil record when trying to answer a burning, but unanswerable, question. In paleoanthropology, the difference between what we know concretely to have existed and what could possibly have existed given the scraps of evidence we have is sublime. The teacher who keeps to the facts is dry and boring to most, and the one who embellishes is interesting to the uninformed majority. It is a shame, but, as with all knowledge, beauase learning is active it is ultimately the responsibility of the learner. It turns out that the only way you can really overcome bias is to learn the record for yourself, but it is vast. Many sites are small and have only yielded a few specimens, sometimes with no date at all. Some sites are large, well-dated, and serve as major datapoints. Every site has a different history of discovery, political history, and history of people working there. Additionally, the ENTIRE human fossil record has been compiled in just under 200 years. Things have grown quite rapidly and chaotically. So the experimental lab is quite different from that of a chemist or physicist. The next links allow you to get a sense of how vast the record is.
More information