The origin of species

1. The Origin of
Species
Presentation about the different
theories which tries to explain this
phenomenon

2. Introduction
• There are two big groups in which the origin
of species are divided:
Non-evolution theories: Creationism and Fixism
Evolution ones theories: Lamarckism. Darwinism and
Neo-Darwinism

3. Creationism
• Creationism is the religious belief that
humanity, life, the Earth, and the universe are
the creation of a supernatural being, most
often referring to the Abrahamic God.

4. Fixism
• They are beliefs that affirm the different species of
the planet have remained invariable throughout the
time.
• All the alive beings were created as we see them at
present. The Nature does not change, it was ended
and unaltered from his formation.
Cuvier thought that Cuvier, to the
changes were produced thelft, and
by huge catastrophes; Linneo, to the
this theory is called: right, supported this
“Catastrophism” theory

5. Lamarckism
• Living beings are distributes from simple
(appeared by spontaneus generation) to more
complex ones (by progresive transformations)
• Evolution is explained due to the function
creates the organ.
• Transformations suffered by an organism are
transmited by heredity to their offspring
A good example are
the famous case of
the girafe´s neck

6. Darwinism
• Current species are originated by ancient, common
ones.
• It explains the evolution with the next steps:
-Species suffer variations, which can cause advantages
or disavantages.
-Natural selection will choose the “good” ones and
they will be transmited to their offspring.
• Darwin know nothing about genetic

7. Neo Darwinism
• It´s the synthesis of:
-Genetic discoveries of Mendel, that explains
how variations are produced.
-Natural selection theory formuled by Darwin
Mendel rules Natural selection Neo Darwinism

8. Thanks you for reading me