Evolution of Life on Earth

Prokaryotes emerge

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Prokaryotic Cells
Approximately 3.8 billion years ago, the first prokaryotic cells emerged. These include bacteria and archaea. Prokaryotes do not have any internal membranes.

Photosynthesis

May 1, 764

Cyanobacteria
Cyanobacteria are beleived to be the first photosynthestic organisms. The development of photosynthesis oxygenated earth's atmosphere and allowed for other life forms to develop.

Eukaryotic Cells

Jul 8, 1179

Eukaryotes
Eukaryotes are more complex than prokaryotes. They have membrane bound organelles within their cytoplasm. Membranes allow for compartmentalization, and more efficient energy flow. It is widely beleived that membranes first emerged as a result of endosymbiosis between several prokaryotes.

Multicellular Life

Oct 10, 1594

protists
About 1 billion years ago, multicellular life evolved. The membranes of eukaryotes allow for cellular specialization and interdependence among cells. Some of the first multicellular organisms were protists.

First Animals

Nov 11, 1760

Protozoa
600 million years ago, the simplest animals appeared on Earth. Protozoa, or first animal, lack any internal organ systems. However, cells work as a cooperative unit.

Fish appear

Apr 14, 1802

First Fish
500 million years ago, the first fish appear. These jawless fish are beleived to be the first vertebrates on Earth.

Land Plants

Oct 5, 1812

Bryophytes
About 475 million years ago, plants moved onto land. The first land plants were bryophytes which we call mosses. These have no vascular system and a dominant gametophyte generation.

Insects emerge

Dec 19, 1843

Insects
The first insects appeared approximately 400 million years ago. They have since become the most proliferous class of organism on Earth.

Gymnosperms

Dec 19, 1843

Gymnosperm
Gymnosperms, more commonly known as pines, evolved roughly 400 million years ago. Newly evolved characteristics of the gymnosperm include vascularization, and seeds. The sporophyte generation is still dominant.

Reptiles

Jun 16, 1885

Reptiles
The oldest known reptile fossil is approximately 300 million years old. Some of the reptile species living on Earth today evolved around this time.

Flowering Plants

Jan 7, 1956

AngiospermsAngiosperms, or flowering plants, first emerge 130 million years ago. Characteristics of angiosperms include dominant sporophyte generation, seed coat, and fruit.

Dinosaur extinction

Jan 2, 1983

DinosaursAfter roaming the Earth for over 220 million years, all non-avian dinosaurs died off roughly 65 million years ago.There are several possible explanation for why this is.

First life appears on Earth

Jan 1, 2000

Miller Urey ExperimentApproximately 4.54 billion years ago, life first emerged on Earth. The Miller-Urey experiment recreates the conditions of Earth that led to spontaneous polymerization.

The genus Homo emerges

Dec 21, 2008

Homo habilisthe hominid genus Homo first appeared 2.5 million years ago. The first member of this genus was the Homo habilis.

First Humans

Dec 2, 2009

Becoming HumanThe modern human species first emerged only 200,000 years ago. It is beleived that tHomo sapiens originated and Africa and colinated the globe from there.

Neanderthals die off

Dec 28, 2009

NeanderthalsFor approximately 175,000 years, both humans and Neanderthals inhabited the Earth. No two species can survive indefinitely while filling the same niche. neanderthals dissapeared 25,000 years ago.