Chapter 7 Flashcards
Ichthyosaurus
fish lizard
What were some of Mary Anning’s discoveries?
She excavated a complete fossilized skeleton of an ichthyosaurus (fish lizard), Pterodactylus macronyx (flying creature), and a Plesiosaurus (fish creature)
Why were Annings discoveries and contributions not recognized as much as they should have been?
Because the Geological Society of London was closed to women
Extinct
terminated or vanished
Extant
still surviving
Deep Time
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
Uniformitarianism
Charles Lyell’s theory claimed the
doctrine that Earth’s geologic formations are the work of slow geologic forces
Catastrophism
the belief that Earth’s formation was due to a set of relatively
quick biblical catastrophic events
Fossils
the mineralized copies of once-living organisms
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
Why is the study of fossils important in anthropology?
because these answers provide insights into human evolution
Eon
The largest subunit of geologic time
Era
An eon is further divided into eras
Period
eras are divided into periods
Epoch
periods are divided into epochs
Holocene
the current epoch
Anthropocene
This has led some scientists within the stratigraphic community to argue for a new epoch beginning around 1950 with the Nuclear Age called the Anthropocene. The major event that marks the boundary is the warming temperatures and mass extinction of nonhuman species caused by human activity
What are some arbitrary ways scientists might determine where one unit of time begins and another ends?
Events like
significant shifts in
climate or mass extinctions can be used to mark the end of one geologic time unit and the beginning of another
Summarize the current debate about the epoch we are currently in. Include human activity in your answer.
Some say it is simply a warm blip in a larger epoch that includes the Pleistocene and not a new epoch called the Holocene. Others say human-driven climate change is warming the world and changing environmental patterns faster than the natural cyclical processes, which means a new epoch from the industrial revolution called the Anthropocene should be formed.
Abraham Ortelius
Ortelius came up with the concept that one supercontinent called Pangea had existed much earlier in Earth’s history
Pangea
One supercontinent called Pangea existed much earlier in Earth’s history. Approximately 200 million years ago, Pangea started to slowly break apart, with the resulting pieces of land shifting and moving through the process of continental drift.
Continental Drift
Pangea started to slowly break apart, with the resulting pieces of land shifting and moving through the process of continental drift
Laurasia
one of the two supercontinents
Gondwanaland
one of the two supercontinents
Alfred Wegener
There was a debate where there was suspicion that there wasn’t enough time for landmasses to move. However, he found fern fossils on every continent, which made him realize all of the continents had to have been connected at one point, which led him to create the tectonic plate theory.
Glossopteris
the name of the fossilized remains of a fern that Alfred Wegner found
Tectonic Plate Theory
Earth’s landmasses are relatively thin, brittle fragments floating on top of hot, squishy material. There is bound to be movement, even of large fragments. Furthermore, there are ridges or shelves in the Atlantic and Pacific Oceans that reflect the shifting of the planet’s crust. This theory not only supports the breakup of Pangea but also provides the basis for our current understanding of how earthquakes work.
What does the Red Panda tell us about a “supercontinent?”
Red Panda fossils have been found four million years to the late Miocene era. They are considered living fossils because they have changed so little in millions of years and because they are represented in the fossil record. Thus, the existence of the red panda in the Miocene in the Appalachian Mountains but living only in Asia today is clear evidence that the red panda moved freely and that our continents were part of a supercontinent.
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 have anthropologists learned from Suddern Farm?
Since there is no universal or “normative” burial rite, taphonomic study is crucial to figuring out what cultural and ritual processes were operating at this time. P78 may represent a special ritual burial associated with violence or punishment. By better understanding the processes that occur in and to the body after death, we can reconstruct the cultural, biological, and geologic processes that affect remains.
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.
Bog Bodies
a dead body that is preserved through peats/soil from wetlands
Anaerobic
absence of oxygen
Ice mummy
a specimen of human remains that is naturally mummified by extreme low temperatures.
What are special circumstances in which bodies can be preserved for many years?
The most important element in the preservation of remains is a stable environment
What role does oxygen play in the body’s decay?
Much of the bacteria that causes decay is already present in our gut and can begin the decomposition process shortly after death during putrefaction. Since oxygen is necessary for the body’s bacteria to break down organic material, the decay process is significantly slowed or halted in anaerobic conditions
Fossilization
the preservation of an organism against these natural decay processes
Lithification
the weight and pressure of the sediments squeeze out extra fluids and replace the voids, that appear in the remains as they decay, with minerals from the surrounding sediments. Lithification is how soft sediments, the end product of erosion, become rigid rock
Premineralization
This is when the organism is fully replaced by minerals from the sediments
Why don’t most creatures end up fossilized after death?
There are many stages in fossilization and if the process is disturbed at any of the stages, the organism will fail to become a fossil. After all, organisms are set up to deteriorate after we die. Bacteria, insects, scavengers, weather, and the environment all aid in the process that breaks down organisms so their nutrients, molecules, and elements can be returned to Earth to maintain ecosystems.
Petrified wood
Another type of fossilized plant. This fossil is created when actual pieces of wood—such as the trunk of a tree—mineralize and turn into rock. Petrified wood is a combination of silica, calcite, and quartz, and it is both heavy and brittle. Petrified wood can be colorful and is generally aesthetically pleasing because all the features of the original tree’s composition are illuminated through mineralization.
How does wood become petrified?
It forms when plant material is buried by sediment and protected from decay due to oxygen and organisms.
Hominins
includes all human ancestors who existed after the evolutionary split from chimpanzees and bonobos
Homo Sapiens
Modern humans are Homo sapiens
Australopithicus Afarensis
is an extinct species of australopithecine which lived from about 3.9–2.9 million years ago (mya) in the Pliocene of East Africa
“Lucy”
A hominin that is 3.2 million-year-old fossil of Australopithecus afarensis that was discovered in Ethiopia in 1974. Originally thought to be the most complete until the discovery of little foot.
“Little Foot”
Little Foot is more complete than Lucy and possibly the oldest fossil that has so far been found, dating to at least 3.6 million years
Sahelanthropus tchadensis
The oldest hominin fossil is a fragmentary skull named Sahelanthropus tchadensis, found in Northern Chad and dating to circa seven mya
Amber
fossilized sap of coniferous trees
How does amber preserve insects or other forms of life?
Sometimes pieces of amber contain inclusions such as air bubbles or insects that become trapped in the sap
What actual discovery might provide insight into ancient DNA?
the recent discovery of a tick that fed off of dinosaur blood that is trapped in amber
La Brea Tar Pits
A famous fossil site from California has asphalt that bubbles through the cracks in sidewalks
