The earliest sedimentary rocks:
- frequently called Azoic (lifeless) Rocks, or Archaeozoic (primordial life) --> it is asserted that these substances require the activity of living things for their production, therefore supposing that the first life was soft living matter with no shells or skeletons, and that its chemical influence caused the deposition of graphite and iron oxide - e.g. marks made by worms
- Proterozoic (beginning of life) Rocks
- Palaeozoic (ancient life) -- show evidence of a diversity of shellfish, crabs, worms, seaweeds, fishes
- Mesozoic (Middle life) Rocks -- fossil-bearing rocks, including bones of giant reptiles
- Cainozoic (recent life) Rocks
Causes for changes in the world's climate:
1. '...the earth does not spin in a perfect circle round the sun. Its path or orbit is like a hoop that is distorted...elliptical...slowly distorted by the attractions of the other planets' --> when the orbit is most nearly circular, the earth must be consistently getting the same amount of heat from the sun; when the orbit is most distorted, then there will be a season in each year when the earth is nearest to the sun (Perihelion) and a season when it will be at the farthest from the sun (Aphelion)
2. the change in the seasons is due to the fact that the equator of the earth is inclined at an angle to the plane of its orbit
3. the precession of the equinoxes: the slow wabble of the pole of the spinning earth takes 25000 years
-- when it happens that at the same time, the orbit is most nearly circular, spring is at perihelion and autumn at aphelion, the climate will be warm and uniform and there will be least difference of summer and winter
4. Forces within the world itself - particularly, the influence of vegetation, especially that of forests
5. Appearance of human communities
Cainozoic period divided by its climate changes:
1. Eocene (dawn of recent life): an age of exceptional warmth
2. Oligocene (little of recent life): climate was still equable
3. Miocene (living species still in minority: general temperature was falling
4. Pliocene (more living species): climate still at its present phase
5. Pleistocene (great majority of living species): long period of extreme conditions --> The Ice Age
The development of mammal from the Lower Palaeozoic Age
- Fish, a vertebrated animal that breathes by gills and can only live in water
- Amphibian - a fish that has developed the power of breathing air, and limbs in place of fins
- Reptile - an amphibian that passes through its tadpole stage; from the beginning, it breathes in air
- Mammal - a sort of reptile that has developed a protective covering and retains its eggs in the body until it hatches
- Hair was the earliest distinction of mammals from the rest of the reptiles
- The mammal is a family animal which seeks for a continuity of experience / life
The development of the sub-human
- Heidelberg man (Homo Heidelbergensis), about 600,000 -200,000 years ago
- Neanderthal (Homo Neaderthalensis) discovered near Dusseldorf
-- distinguishing feature: Piltdown jaw-bone - 'has the broad, flat symphysis of the Apes'
- Tasmanians
- Late Palaeolithic Age: 1) Cro-Magnon race, 2) Grimaldi race
- Main features: human fore-brain, human hand, and an intelligence
- no trace of intermixture between the races
- hunting people who lived largely in the open (Neanderthals lived mostly in caves)
Neolithic (Stone Age ~ 10,000 BC) man
- characterized by: 1) the presence of polished stone implements esp. the stone axe; 2) the beginning of agriculture; 3) Pottery and proper cooking; 4) Domesticated animals
- cultural fundamentals: 1) the fear of the Old Man --> Taboos and the ideas of forbidden things; 2) the idea of Uncleanness and of being cursed
- the development of speech and language = the development of thought, the capacity for systemizing things
-with agriculture = rise of religion --> ceremonies, sacrifices, 'purified class of people'
*Zoic: relating to (animal) life
*Cene: denoting a geological period
*Lithic: relating to stone
*Equinox: when the plane of Earth's equator passes through the center of the sun - generally March and September, when the Earth experiences nearly equal lengths of day and night
*Equator: the imaginary line around the middle of the Earth, halfway between North & South Poles
No comments:
Post a Comment