GEOLOGY 135: Geology and Evolution
The Process of evolution is tied to
many other Geological Processes.
Evolution is the process by which life and biodiversity developed.
Evolutionary history illustrates the way in which
events of the past created the conditions of the present
and how conditions in the present set the stage for events now
and in the future.
The History of the planet and its rocks, water, and atmosphere,
and the history of life are thus intertwined:
1) Origin of life--Life arose as a product of the early earth atmospheric chemistry. Life was possible only because of this planet's unusual (unique?) conditions, especially those relating to temperature and the combination of elements that were abundant.
2) Species--have been shaped through time by adaptation to gravity, chemistry of the atmosphere and hydrosphere, weather and climate, topography and relief.
3) Ecology--the interaction of organisms and their environment--is completely intertwined with the rock cycle, the carbon cycle, the water cycle, and many other geological processes.
Ecological processes also contribute to geological processes.
The Sciences of Geology and Biology are historically intertwined:
Darwin was only one of dozens of geologists/biologists travelling the world in the 17th and 18th century,
collecting specimens of rocks, minerals, plants, and animals,
and recording data about volcanoes, coral reefs, forests,
springs, rivers, lakes, fossils, and peoples.
He is recognized because his theory was the most successful
at explaining the big questions of the day:
1) Where did we (and plants and animals) come from?
2) Why were animals and plants of different rock strata different
from each other and from today?
3) Why are animals and plants on different continents different?
(There is still work to do on the processes behind these questions.)
1) Origin of life.
Life on our planet is carbon based.
Carbon compounds are scattered in space and our atmosphere.
Life is the organization of carbon compounds
with O, H, N, S, Ca, Fe, Mg, Cu, etc.
(oxygen, hydrogen, nitrogen, sulphur, calcium, iron, magnesium, etc.) (some single cell plants and sponges use Si)
(Why is life carbon-based, not silica-based?)
These elements are self-organized into molecules that can
1) get energy out of chemical reactions,
and 2) replicate themselves.
Evolution is the 3 billion year history
of DNA molecules making proteins, fats, and starches
into competitive and predatory organisms
that are in a continual race to succeed
at survival and reproduction.
The main energy source is solar light and heat.
The dominant energy capture mechanism is photosynthesis,
which makes sugar out of water and CO2,
releasing waste O2 (this is where atmospheric O came from)
6CO2 + 6H2O -----------------------> C6H12O6 + 6O2
The rest of the food chain is based on predation
and bacterial decomposition.
(Bacteria have lots of alternative chemical energy sources)
2) Species are the individual units that survive or fail
depending on the successful reproduction of their organisms.
Adaptation is the process of changing,
through differential survival and reproduction
to changing conditions
The Red Queen Hypothesis: Every species is changing,
so, successful adaptation requires continual change.
The variation on which change is based is mutation of DNA
Differential survival and reproduction is "Natural Selection"
3) Ecology depends on
landscape and other organisms,
climate and weather,
geological & chemical cycles: e.g., Water, Rock, Carbon, etc.
lakes and oceans
3 kinds of
soil and rivers
dissolved organic carbon food-chain
bacterial food chain
diagram a Carbon cycle for your garden and yourself)