Paleontology – The Study of Ancient Organisms
Paleontology refers to the study
of prehistoric life forms. Most researchers in this
field focus on the process of evolution and how life
on Earth has developed over time. Factors considered
by the paleontologist include climate change, migration,
and species interaction. Paleontologists also work
closely with geologists to correlate fossils with
the geological record.
Although ancient fossils have led
to intrigue and inquiry for thousands of years, formal
study in this area began in the late 18th century.
It was at this time that Georges Cuvier confirmed
that extinction was a real phenomenon. Perhaps the
most notable paleontologist in history was Charles
Darwin. Darwin collected mammalian fossils in South
America and plant remains in Patagonia. By studying
fossils along with existing organisms, Darwin was
able to formulate his theory of evolution and publish
his famous thesis Origin of Species in 1859.
Paleontology research is frequently
conducted using fossil evidence. However, remains
of tracks, burrows, food products, and feces may also
be used. Material finds can be dated using a variety
of methods. One of the most popular is carbon-14 dating,
which was developed by Willard Libby in the mid-1900s.
Carbon-14 dating relies upon the decomposition of
a naturally occurring radioisotope. Another method
of dating is dendochronology, which uses rings in
the cross-section of a tree to determine its age.
A tree produces one new ring each year, and the thicknesses
of each ring can indicate environmental changes. Paleontologists
can also date fossils by studying the location where
they were found and by comparing them to other fossils
of known age.
Paleontologist attempt to create
genealogical correlations between the species they
study to illustrate the process of evolution. This
hierarchal classification process is known as cladistics.
Cladistic study frequently involves the use of DNA
sequencing data, which can sometimes be gathered from
even the oldest fossils. To supplement genetic information,
scientists use comparative anatomy to place organisms
within the evolutionary chain. The final result of
data analysis is a cladogram, which is a graphical
representation of a species’ evolution. Complex
cladograms include numerous branches and connections
between organisms.
Some of the most fascinating topics
in paleontology are cases of mass extinction. Paleontologists
tend to focus on five major extinction events. In
each case, more than half of a species’ population
died off during a relatively brief period. The most
well-known of these is the disappearance of the dinosaurs.
There was also an event prior to the dinosaur extinction,
which resulted in a loss of more than 80% of all marine
species. A more recent extinction event was the dying
off of most megafauna species at the end of the last
ice age.
Within paleontology, there are several
distinct sub-fields of research. From micropaleontology,
the study of microfossils, to paleoanthropology, the
study of prehistoric hominids, the possibilities for
exploration seem endless. Thus, research into this
field continues to gain popularity among scholars.
With each new discovery, we learn a little more about
the evolution of our planet and can better predict
future evolutionary developments.
|
