| |
|
|
| |
 |
| Organic Evolution |
|
| |
| Chemical evolution resulted in the formation of life on earth about 3.8 billion years ago. The primitive cells that resulted from this process gradually gave rise to primitive forms of organisms such as bacteria, algae, fungi and protozoan. These organisms in turn, gave rise to a variety of forms of life that exist today on Earth. The term organic evolution is used to describe the slow and gradual process by which living organisms have undergone changes from the simplest unicellular forms of life to the most complex multicellular forms that can be seen today. The process is the result of innumerable modifications which the living organisms have developed and passed on to their offspring. Hence, organic evolution is described as 'descent with modifications'. |
| |
 |
| |
| fig. 5.1 - Evolution of Life According to the Fossil Record |
| |
 |
| |
| fig. 5.2 - Chemical and Organic Evolution |
| |
|
|
| |
|
|
| |
|
|
|
|
|
Get FREE Live Tutoring
(No credit card required)
Customer Care
Click to get customer service, technical support and subscription help.
Refer-A-Friend
Get One Month Free!
When you refer a friend
|
|
|
