Brief history of life on Earth Flashcards
What are the three domains in life?
- Eukaryotic
- Bacteria
- Archaea
Eukaryotic kingdoms are
- Protists - Eukaryotes, primarily unicellular organisms such as algae. They are heterotrophic or photosynthetic
- Fungi - Eukaryotic, mostly multi-cellular, hetrophic with a chitin cell wall
- Animalae - Eukaryotic, multi-cellular, motile, heterotropic
- Plants - Eukaryotic, multi-cellular, photosynthetic
Archaebacteria
Prokaryotes that lack a peptide-glycan cell wall, extreme halophiles, thermophiles and methanogens
Eubacteria
Prokaryotes with a pepidoglycan cell wall. Examples include cyanbacteria
How old is the Earth?
4.5 billion yrs old
3.8 billion years ago
Earliest isotopic life evidence
3.5 billion years ago
Earliest fossil found
2 billion years ago
Atmosphere became oxygenated
0.6 billion years ago
Hard shelled organims developed
What are stromatlites?
- Pre-cambrian bacteria cities which produced oxygen
- Helped to oxygenise the atmosphere
When did cyanobacteria develop?
3.5 billion years ago
A theory of how eukaryotics first formed?
- Infloding of plasma membrane
- Engulfing of aeorbic heterotrophic prokaryotes and photosyemic prokaryotes
- Leading to a endosymbiobiotic relationship
How did multi-celled ekaryotes arise?
Evolved from single-celled Eukaryotes living in close association to each other
When did sex gametes and complex DNA evolve and what did it lead to?
- 570 million years ago
- Led to a explosion in life and diversity
When was land colonised?
500 million years ago