bacteria and history of life

Evolutionary History of life on Earth

1. Planet Earth formed

2. Earth's core and crust formed

3. The Earth's first oceans formed

4. The first life appeared on Earth

5. Oxygen began to accumulate in the Earth's atmosphere

6. The first animals evolved

7. The first animals with backbones (fish) evolved

8. The first land plants evolved

9.  The first land animals with backbones evolved

10. The first dinosaurs evolved

11. The dinosaurs went extinct

12. Modern humans evolved

What determines if something is living?

Movement- It can change position by itself

Respiration-  A chemical process in which energy is released

Sensitivity-  Detecting changes in the surroundings

Growth- Is able to expand by cell division

Reproduction- Is able to create more of its kind

Excrection- Getting rid of waste products

Nutrition- Is able to take in and use food

Theories of how life began

Spontaneous generation  -   In ancient times people believed that non  living things could suddenly transform into living things. This was disproved by Louis Paster in 1860.

Life from outer space  -  In the 1900s people first believed that micro organisms flew in from space onto Earth. This was called Panspermia

Miller Urey , Primodial soup  -   Stanely Miller and Harold Urey, using the processes of boiling, sparking and condensing among the gases which would have been present in Earth's atmosphere a long time ago (water, ammonia, methane and hydrogen) produced ameeno acids which are the building blocks of proteins.

RNA world  -  Some scientists beleive that at some point in history there was an RNA world. RNA is very similar to DNA except for the fact that RNA can come in many shapes and is usually single stranded, whereas, DNA is double stranded and…