1. Ecology and Evolution Introduction (cont.)

2. Ecological Revolution Darwin 1859 Origin of Species Haeckel 1870s Broaden’s “Ecology” Industrial Revolution Human Population Explosion ↑Materialism ↑Resource exploitation ↓Habitat (Environmental) Quality ↑Need for understanding human impact on planet including studying organisms and their surroundings N time i.r.

3. Biological Hierarchies Ecological Revolution at all scales of ecological hierarchy. Habitat – place or physical setting in which and organism lives

4. … and at all levels of species diversity when ecologists take into account the evolutionary relationships among organisms. Evolutionary hierarchy

6. How does the physical (abiotic) environment affect life on earth? Concept behind the idea of the habitat: –The abiotic environment tends to place constraints on life. –example: blood and tissues of vertebrates tend to freeze above temperatures found in antarctic waters. Notothenoid fish -1.9° C glycopeptide and peptide antifreeze compounds Outer-tissues have ice on them and the spleen Biology = solutions

7. Other constraints Gravity –solutions: –Flight: wings, metabolic level –Gliding: mammals, frogs, snakes –Bones Arid Environments (no water for photosynthesis) –solutions: –Cactus: waxy outer covering, –stomata, ↑storage capacity, –suberized roots etc.

8. Main points Live exists in constant tension with its abiotic, physical surroundings (habitat) Tolerance for extremes for chance to reproduce. Reproduction Growth and repair Survive and maintain Energy available Life and Ecosystems are in a state of non-equilibrium

9. Consideration of some abiotic elements important for life A.Water 1.Abundant on Earth 2.Excellent solvent 3.Facilitates the movement of many organisms 4.Main ingredient in photosynthesis 5.Remains in liquid state over a large range of temperatures 6.Resists change in state 1.to freeze: remove 80cal/g 2.to evaporate: add 500cal/g 7.Thermal inertia 8.Density and Temperature

10. Density and temperature of water Substance X –cools becomes more dense Water –cools becomes more dense to about 4° –then expands! (ice floats) density temp 4°4° Why important? Bottoms of bodies of water do not freeze floating layer of ice + layer of snow = insulation dormant plants and reproductive bodies

11. Excellent solvent Natural waters contain dissolved substances that are building blocks of life B. Solutes Na, Cl, Mg, SO 4 N – nucleic acids, protein P – na, phospholipids, bone S – proteins K – solute in animal cells Ca – bone, plant structures Fe – Proteins (hemeglobin)

12. C. Carbon and Oxygen solutes that receive special mention –Immediately tied to life via: acidity respiration and photosynthetic reactions D. Light and Heat Sources of heat: –Sun –Geothermal –Metabolic