Life, the Ocean, and Everything

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Life, the Ocean, and Everything
with apologies to Douglas Adams.
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Despite the great diversity of life on Earth and
in its oceans, there is uniformity in the
underlying mechanisms for Energy use and
transfer, Protein manufacturing,
Communication of genetic information Basic
building blocks used by all organisms.
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Energy transfer (needs 2 steps)
1. Energy is bound in a carbohydrate molecule
by
Photosynthesis
6 H20 6 CO2 solar energy--gt C6H12O6 6 O2
OR
Chemosynthesis
6 H2S 6 CO2 chemical energy--gt C6H12O6 6S2
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Energy transfer
2. Energy is released from the carbohydrate
molecule in respiration
C6H12O6 6 O2 --gt 6 H20 6 CO2 metabolic energy
(process can also be anerobic - no oxygen)
ALL life use the molecule ATP at the cellular
level to transport metabolic energy.
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Protein Manufacturing
Proteins are the building blocks of cells and ALL
cells contain protein factories called ribosomes
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Communication of genetic information
ALL cells use DNA as a template for
reproduction.
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DNA similarities Humans share 99 of the same
DNA with ALL other humans
98 of the same DNA with chimpanzees
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Common Building Blocks
ALL cell walls are made of lipids (fats)
ALL cells use proteins for structures
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Scientists infer from the fact that ALL life
shares these underlying mechanisms for energy
transfer, protein and lipid construction and use,
and reproduction that these mechanisms developed
very early in Earths history.
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All life in the ocean depends on
phytoplankton generating carbohydrates
Notice the pyramid shape, with each higher layer
dependent on the lower one and 101 ratio at each
step.
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Most carbohydrate comes from phytoplankton
Carbohydrate amount
Source
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Phytoplankton supply 40 of the worlds
carbohydrates and thus energy for life
Oceans Land
Carbon productivity
40 60
0.1 99.9
Biomass
and use only a fraction of the biomass.
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Carbon is cycled throughout the Earth
45 of the carbon back into the atmosphere
via respiration (CO2). 45 goes to
biomass. 10 dissolves back into the ocean (as
CO2).
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Other elements needed for life (also in cycles)
Nitrogen- needed for proteins
Phosphorus - needed for ATP
(adenosine triphosphate)
Iron, trace elements needed for enzymes in
reactions
Often controls growth of phytoplankton because
very insoluble in sea water and thus very small
quantities available.
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Most of life is built on the conversion of solar
energy to carbohydrates.
THIS REQUIRES LIGHT!!!
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Photosynthetic plankton and plants
Chemosynthetic bacteria
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Many organisms in the ocean are chemically in
equilibrium with the water 1. They are
ectotherms (body T outside T) 2. They are
isotonic (body salinity ocean salinity)
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In simple organisms like corals, ALL cells
exposed to sea water with nutrients
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In more complex organisms, blood is needed to
circulate nutrients and remove wastes. No cell
is more than 1-2 layers away from blood!
Body fluid salinity sea water salinity for
ALL animals with circulation systems.
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Sea water is chemically similar to body
fluids for many different types of
organisms (e.g. hemoglobin in both you and
earthworms)
Body fluids must have developed very early in
the history of life.
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What do we know about the origins of life?
First cells appeared when there was little or
no oxygen in the atmosphere
No oxygen means no photosynthesis and only
chemosynthesis.
http//www.windows.ucar.edu/
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Oxygen levels rise, so we know that some cells
were beginning to photosynthesize.
Not until 2 By did organisms begin
respiring (sugaroxygen --gt energy CO2 H2O)
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Only after oxygen levels exceed 1 do we see
multi- cellular organisms
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There is great diversity of life in the
ocean. Where did it come from?
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How did the diversity develop?
Mutations and, more importantly, exchange of
genetic material lead to new variations.
Evolution!
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Note Adaptation of a single organism to a
changing environment is NOT evolution. Those
adaptations die with the individual because they
are NOT coded into the genetic information!
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Under the assumptions that all groups with one
or more common life mechanisms once shared a
common ancestor AND that groups with more
common traits are more closely related than
ones with fewer common traits, we get this
summary of our knowledge of life
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Part of the diversity results from the great
diversity of habitat in the oceans - many
different ways to make a living without
competing for the same space!
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Lots of habitats..
Benthic (bottom) OR Pelagic (water)
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