The Origin of life

Origin from nonliving matter

Scientists believe that life arose earth had cooled. They stated that random events probably produced stable molecules that could self-replicate. Then, natural selection favored changes in the rate of reproduction, which eventually led to the first cell.

Birds

descendants of small insect eating dinosaurds.

Massive reptiles

dinosaurs.

Jawless fishes

earliest vertabrates.

Reptiles

evolved from amphibians. gave rise to a variety of species that gradually replaced the amphibians as the dominant terrestrial animals,

Scorpions

first arthropods to live on land

Eubacteria

first group of oldest fossil found True bacteria, most living bacteria, including those that cause disease and decay.

plants and fungi

first living things to populate the surface of earth

Amphibians

first vertebrates on land.

coacervate

formed bubbles when lipids is mixed with water.

Archaebacteria

second group of true fossils/oldest fossil found ancient bacteria. They are found mainly in hostile environments where conditions resemble those of early earth.

Arthropods

First land animals. animals with hard body covering and jointed legs. (insects)

Cynobacteria

The bacteria that produxed oxygen of early earth. They are photosynthetic. As they carried photosynthesis, oxygen gas is released in the oceans

Extraterrestrial origin

The hypothesis explains that life originated on another planet outside the solar system. Life was then carried to earth on a meteorite or asteroid and colonized earth.

Panspermia

The theory presumes that the seed of life exists all over the universe and can be propagated through space, and that earth originated from those seeds.

4.5 billion years

age of the earth

Vertebrates

animals with backbones. (notochords and vertebral column.)

Divine creation

many people believe that life was put on Earth by Divine forces. Creation theories are common to many of the world's religions and cultures.

Eukaryotes

much larger than prokaryotes, contained a central nucleus and a complicated internal structure.

Prokaryotes

organisms whose cells lack a nucleus. the first of this is anaerobic.

Stanley Miller

recreated the conditions of the early earth to show how organic molecules are formed.

Mycorrhizae

unique mutualistic partnership of plants and fungi. Plants provide food to the fungi while the fungi provide nutrients obtained from organic matter to the plants.

ozone

was produced when more oxygen began to diffuse into the upper atmosphere.