Darwin and Lamarck's Theories on the Evolution of Different Organisms (Essay Sample)

EVOLUTION 

ü  Evolution attempts to explain the origin, diversity and unity of life.

ü  It’s a gradual change of living organisms from simple life forms to more complex forms over a long period of time.

ü  The origin of life

ü  Theories to explain origin of life

ü  Special creation

ü  This is a belief that is held by all the world’s major religions and also found in folklore.

ü  This theory narrates that the whole universe and all that it contains was created by the action of a supreme being (God). To “create” means to bring into existence something out of nothing.

ü  This belief holds the following views on the origin and nature of life;

• -That life was brought into existence by a Supreme Being
• -That life forms were created in a perfect form and have remained unchanged over time.
• -That this knowledge is based on faith and cannot be disputed
• -The belief cannot be contradicted by science since it is not scientifically testable.

ü  Chemical evolution

ü  This theory suggests that life probably began through a catalytic effect of light bringing together elements to form simple molecules such as water (H₂O), Ammonia (NH₃) and Methane (CH₄).

ü  It can be theorized that, millions of years ago simple molecules such as hydrogen, oxygen, nitrogen etc in the universe combined in various proportions to form different simple compounds such as water and ammonia.

ü  Further combinations of such compounds resulted in the formation of complex molecules e.g. DNA. Successive replication of the molecules led to the formation of simple forms e.g. viruses and bacteria.

ü  The period during which the chemicals combined to form the 1^st living organisms is called the period of chemical evolution of life.

ü  This theory holds the following views on the origin and nature of life;