Transcript Life on Planet Earth

Earth Sciences 083F:
Life on Planet Earth
The Joy of Rex:
Why Study the History of Life ?
Fossils are cool !
We want to know where we came from !
Humans (and all other organisms on Earth) are the products of at
least 3.5 billion years of evolution. Many theories have been
proposed on the mechanisms of evolutionary change. But the only
the fossil record can tell us WHAT happened.
Fascination of the past
Humans have a deep-seated interest in what life was like in the deep
past. Many organisms have come and gone in Earth’s 4.5 billion year
history. Fossils are time machines that provides us with information of
past life.
The ultimate detective story
Everybody loves a good detective story. Paleontologists draw on many
lines of evidence to deduce how ancient living things lived, how they
interacted, and how they died.
The fossil record provides evidence of evolution.
But why is evolution relevant to us ?
Evolution is one of the unifying threads in modern science,
providing a framework to guide research in areas as diverse as
medicine to computer programming.
Evolution is not just about biological change in the distant past - it
is happening now. An understanding of evolution is critical for
everything from dealing with bacterial resistance to antibiotics, the
response that different species might have to climate change, and
to understanding our nature and fate as a species.
Many public health problems manifest the ability of viruses and
bacteria to evolve resistance to antiviral and antibacterial
medicines as fast as we can develop new ones. This resistance
comes about through biological evolution. Similar problems exist in
pest resistance to herbicides and insecticides.
Opposition to evolution
Some people cannot see any value in
thinking about evolution. Some defiantly
oppose the concept because it
contradicts their religious beliefs.
Cam’s response: Fair enough
But…it cannot be argued that evolution is
one of the key ideas of modern
civilization. Those with theological
objections to evolution should still have
some familiarity with the concept ! Can
someone legitimately object to an idea if
they don’t understand it ?
Another important point !
The current environmental
crisis has striking parallels with
events that affected life millions
of years ago in the Earth’s past
(the main difference being that
these events were not brought
on by humans – more on this
later).
To predict the possible effects
of environmental change in the
future, we must take a look at
the past !
The past is the key to the future
End of Lecture