evolution

Early Theories About How the Earth Changes

Catastrophism, Uniformitarianism

what is Lamarckism

traits acquired or lost during an organism's lifetime- either by use or disuse are transmissible to offspring

Darwin's Four Observations

More individuals are produced than survive to reproduce

There is variation in fitness among individuals

Fitter individuals leave more offspring

Differences are inherited from parents to offspring

Conditions Required for Natural Selection

Reproduction

Heredity

Variation in characterisitics of the members of the populations

variation in the 'fitness' of organsisms associated with their various characterisitics

Abiogenesis 自發生成

=the orginated evolution of life or living organisms from inorganic or inanimate 無生命 solutions

what is Primordial soup, Hydrothermal vent?

Primordial soup (hypothesis): life began in small ponds full of organic molecules

Hydrothermal vent (hypothesis): life began in deep-sea hydrothermal vents spewing 噴出 superheated water rich in minerals

Miller-Urey experiment

trying to recreate the conditions in primordial soup

using water, methane, ammonia, hydrogen, and electricity.

Produced amino acids, sugars, nucleotides, fatty acids — building blocks of life.

>Panspermia (mechanism)/ exogenesis (hypothesis)

the hypothesis that life originated elesewhere in the universe and came to earth via meteoroids, asteroids,comets,etc

Similarities of life form on Earth:

DNA with the same four nulceotides bases (A, T, G, C) and nearly the same genetic code

use ATP to store and transfer energy

use Left‑handed amino acids, right‑handed sugars

Major Events in Earth's History

1.Hadean Earth 冥古宙地球

Evolution of eukaryotic cells (~1.5-2 billion years ago)

Multicellularity( between 1.56 billion - 700 million years ago)

Ediacaran fauna (635 Myr ago)

Cambrian Explosion (542 Million years ago)

Colonisation of land (~440 Myr ago)

different type of speciation

Morphological /Taxonomic species concept

Biological Species Concept

Phylogenetic species concept

Possible modes of speciation:

Allopatric (no gene flow) ▪ Parapatric (some gene flow) >Populations are adjacent (touching ranges), but experience different environments → divergent selection → partial isolation. ▪ Sympatric (major gene flow) >Speciation occurs within the same geographic area, with no physical separation.

cladogensis and anagenesis

anagenesis : gradual change over time

cladogensis : a single lieage spilt over two