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BIO 111: Foundations of Biology
Lecture 2: Living world
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Lecture II: Living World
III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. ???
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Coccolithophore (single celled marine algae) Lecture I: Living World III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation “Coquina”
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Lecture I: Living World
III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation SHELLS Settled out
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400 m 4 um (4/1000’s of a mm; 250,000 per meter) 100,000,000 deep, but they are crushed, so it’s actually more…
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400 m 4 um (4/1000’s of a mm; 250,000 per meter) 100,000,000 deep, but they are crushed, so it’s actually more… Little things, big effects…
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Where did all the Carbon Dioxide go? Lithosphere Biosphere
to lithosphere Limestone and Dolomite
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Lecture I: Living World
III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation 2. Photosynthesis Photosynthetic bacteria
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Light Dependent Reaction Light Independent Reaction
Overview: A. Step Two: storing that chemical energy in the bonds of molecules e- C6 (glucose) ATP ADP+P 6 CO2 (from air) e- Light Dependent Reaction Light Independent Reaction Where do the electrons come from? Most Photosynthetic organisms split WATER: 2 (H-O-H) O + 4H+ + 4e- O2 (released to air)
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Earth Venus Mars CO2 0.035% 96% 95% N2 77% 3.5% 2.7% H2O 1% 0.01%
Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation 2. Photosynthesis Earth Venus Mars CO2 0.035% 96% 95% N2 77% 3.5% 2.7% H2O 1% 0.01% 0.007% Ar 0.93% 1.6% O2 21% trace Little things (photosynthetic bacteria), big effects…
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3. The Biosphere and the Carbon Cycle
Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet.
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3. The Biosphere and the Carbon Cycle
Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Most has been transferred to the lithosphere by limestone formation
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3. The Biosphere and the Carbon Cycle
Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Most has been transferred to the lithosphere by limestone formation Or trapped as fossil fuels
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3. The Biosphere and the Carbon Cycle
Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Most has been transferred to the lithosphere by limestone formation Or trapped as fossil fuels And there is nearly as much carbon In living terrestrial biomass as in the atmosphere
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3. The Biosphere and the Carbon Cycle
Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Most has been transferred to the lithosphere by limestone formation Or trapped as fossil fuels And there is nearly as much carbon In living terrestrial biomass as in the atmosphere More in the entire biosphere, including decomposing material in soils and marine life
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How do we know that oxygen wasn’t always present in the Earth’s atmosphere? Maybe Earth is just different from Venus and Mars… Banded iron formations are first seen 2.5 billion years ago, showing that oxygen must have been present in the ocean to precipitate iron out of solution as iron oxides in sedimentary strata. There absence in older strata means that oxygen was not present in appreciable amounts.
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The Carboniferous “Pulse”
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Terrestrial plants were radiating, sucking up CO2 and producing O2.
Huge expanses of swamp forests dominated the equatorial zone. Photosynthetic rates were high, but the trees were preserved under sediments when they died and fell…. Creating our coal deposits. Photosynthesis produced lots of O2, but with less decay, it stayed in the air instead of being breathed in and used by decomposing bacteria.
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The K-T Extinction affected atmospheric oxygen levels as plants went extinct and terrestrial photosynthetic activity declined.
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And Today? The Earth is a living planet… It breathes.
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And today? The Earth is a living planet… it breathes. CO2 – increased from 320 to 400 ppm 25% in 50 years O2 – declined by 70 ppm, but it is 21% of the atmosphere (210,000,000 ppm) So the decline of 70 ppm is not dramatic.
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So, the ‘Biosphere’ is a critical component of how the Earth functions
So, the ‘Biosphere’ is a critical component of how the Earth functions. And these functions create an environment to which the ‘biosphere’ has adapted and is dependent upon. Humans, like all life forms, are dependent on these ‘ecosystem functions’ that clean the air, clean the water, and produce biomass (food).
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So, we must help to sustain the biosphere and its functions
So, we must help to sustain the biosphere and its functions. But what is the biosphere? Is it just a unitary ‘thing’? A circle interacting with other subsystems? If we want to sustain it – if we are interested in ecological sustainability – don’t we need to know what IT IS and how IT WORKS? (Reductionism)
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WHAT THE BIOSPHERE IS: An extraordinary diversity of LIVING ORGANISMS
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Millenium Ecosystem Assessment (2006)
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Detritivores Pollinators Insect predators Herbivores
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Pollinators Insect Parasitoids Insect Predators
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Herbivores Pollinators Parasites Detritivores
Malagasy Sunset Butterfly Jewel Bug Herbivores Pollinators Parasites Detritivores Long-legged fly
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Herbivores Detritivores
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(bacteria, algae, and plants)
PRODUCERS (bacteria, algae, and plants)
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Most vertebrate species are fishes
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Herbivores, Predators, Detritivores, Pollinators
Herbivores, Predators, Detritivores, Pollinators
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WHAT THIS DIVERSE BIOSPHERE DOES:
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1) Biodiversity increases “productivity” ... FOOD
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Monoculture They all need the same things at the same concentrations; they compete.
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“Niche Complementarity”
Monoculture Polyculture They all need the same things at the same concentrations; they compete. Combinations of different plants can be planted at higher density, and they use different "niches" and coexist. Even if abundance of "most productive" species drops, this loss can be offset.
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“Positive Effects” Monoculture Polyculture without beans with beans They all need the same things at the same concentrations; they compete. Nitrogen fixing legumes (beans) nutrify the soil, increasing the growth of other plants. And you have beans!
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2) Biodiversity improves ecosystem services
Estimates of various Ecosystem Services - $U.S. trillions Ecosystem services Value (trillion $US) Soil formation 17.1 Recreation 3.0 Nutrient cycling 2.3 Water regulation and supply Climate regulation (temperature and precipitation) 1.8 Habitat 1.4 Flood and storm protection 1.1 Food and raw materials production 0.8 Genetic resources Atmospheric gas balance 0.7 Pollination 0.4 All other services 1.6 Total value of ecosystem services 33.3 Source: Adapted from R. Costanza et al., “The Value of the World’s Ecosystem Services and Natural Capital,” Nature, Vol. 387 (1997), p. 256, Table 2. TOTAL GLOBAL GNP (1997) = 18 trillion. 2) Biodiversity improves ecosystem services
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3) Aesthetics and Inspiration: Biodiversity enriches our cultures
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But do we NEED all these species??
WHY PRESERVE BIODIVERSITY? But do we NEED all these species??
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There’s a lot of redundancy in nature…
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Are all species equally important? If not, which ones are critical?
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with without
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We don’t know which species are critical
So we need to save them all to maintain ecosystem function
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HOW IS THIS DIVERSITY PRODUCED?
Evolution
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Topical Review: - How life speeds the transfer of CO2 to the lithosphere - How photosynthesis changes the atmosphere - How life has changed—and continues to change—the atmosphere over Earth history - What the biosphere is, and the major patterns of Earth’s biodiversity - What biodiversity does for ecosystem function - Why preserving diversity is ecologically important
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