Final Exam Flashcards
Fossils
the mineralized copies of once-living organisms
They used to believe in the Bible but now they don’t after realizing that they found fossils that are older than the Bible
Why was there such resistance to the idea that animals and people may have evolved over time?
To even consider that humans and animals might have evolved over time was practically an admission that the Christian God had made mistakes that needed correction in His creation of Earth and all living things. To think otherwise was considered heresy and was punishable by ex-communication from the Church—or even death. Instead, scientists were still trying to fit geologic evidence into Biblical chronology
Deep Time
Helped us understand how the formation of the Earth would support the theory of evolution.
Scotsman James Hutton’s theory gave the history of Earth enough time—4.543 billion years—to encompass continental drift, the evolution of species, and the fossilization process
Taphonomy
the study of what happens to an organism after death
Why is taphonomy important in biological anthropology?
To obtain as much information as possible from the remains of once-living creatures, one must understand the processes that occur after death. It is so important that many scientists have recreated a variety of burial and decay experiments to track taphonomic change in modern contexts. These contexts can then be used to understand the taphonomic patterns seen in the fossil record
What might taphonomic analysis reveal about human culture, or the challenges people faced?
Taphonomic analysis can also give us important insights into the development of complex thought and rituals in human evolution. Taphonomy helped to establish whether these burials were simply the result of natural processes or intentionally constructed by humans. Taphonomic evidence may tell us how our ancestors died.
How old is the Earth?
Earth is roughly 4.6 billion years old, give or take a few hundred million years.
Laetoli footprints
These 70 footprints, now referred to as the Laetoli Footprints, were created when early humans walked in wet volcanic ash in Tanzania
Discovered by Mary Leakey
What type of fossil are the Laetoli footprints, and what species likely made them?
Since they are footprints they are trace fossils and Australopithecus afarensis made them
What special circumstances allowed the Laetoli footprints to be preserved?
Before the impressions were obscured, more volcanic ash and rain fell, sealing the footprints
What are the two categories of fossil dating techniques?
relative dating methods and chronometric sometimes called absolute) dating methods.
relative dating: relies on simple observational skills that approximate time
chronometric dating: provide specific dates and time ranges that are based on work in other disciplines such as chemistry and physics
Law of Superposition
Essentially, superposition tells us that things on the bottom are older than things on the top. It stands to reason that each layer is older than the one immediately on top of it
What is the potassium argon dating technique?
can reach further back into the past than radiocarbon dating. Used to date volcanic rock, these techniques are based on the decay of unstable potassium 40 into argon 40 40Ar) gas, which gets trapped in the crystalline structures of volcanic material.
measuring the ratio of radioactive argon to radioactive potassium in the rock. Basically, the amount of radioactive potassium decreases as argon increases
What is the radiocarbon dating technique?
The leading chronometric method for archaeology is radiocarbon dating. This change occurs at a predictable rate for nearly all radioisotopes of elements, allowing scientists to use unstable isotopes to measure time passage from a few hundred to a few billion years with a large degree of accuracy and precision.
All organisms are made up of a form of an element called isotopes: carbon 12 (six neutrons). Cosmic rays (high energy particles from the solar system) hit the nitrogen particles of carbon 12 changing it to and carbon 14 (eight neturons). When an animal dies, since the carbon 14 is unstable, every 5,730 years, half of the carbon 14 atoms will decay into nitrogen. We can measure the ratio of carbon 12 to carbon 14. Carbon 12 stays the same while carbon 14 decreases over time after an organisms’s death.
Potassium-argon dating is useful because one can use it to date
very old remains
James Hutton’s theory of ____ was crucial to understanding fossils.
Deep Time
Many fossils are found nearby ancient
lakes
The Laetoli footprints provide valuable information about the ____ of early hominins.
bipedality
What is the visual predation hypothesis?
It’s the idea that humans evolved to have 3D and color vision because we were evolved to hunt insects so this is a way to explain why we have these traits.
Matt Carmill-late 1960s and early 1970s
The visual predation hypothesis was unpopular with some anthropologists. One reason for this is that many primates today are not especially predatory.
