Darwin's Postulates
Darwin's way of Explaining Natural Selection
The first postulate: Variation
Within spices there is variability in size, color and other physical and physiological aspects. Some of this variability can be:
- Differences between cells
- Differences between organisms
- Caused by genetic or environmental
This can be proved with Darwin's Finches in the Galapagos islands, each bird adapted to its environment and have developed different beaks according to their needs.
The second postulate: Inheritance
Some of the variation is heritable, we obtain features inherited from parents through genes. Things we may inherit through our parents can be:
- Eye Color
- Size
- Skin color
The third postulate: Population expansion
The only way a species can survive is by reproducing themselves, but since there are limited resources species have to fight for them if they want to survive. The strong and fit are the ones who are able survive because of the features they have that allow them to win against rival species. An example top predators like:
- Great white sharks
- Humans
- Cheetahs
The fourth postulate: Non-Random Survival and Reproduction
It is not by chance that certain species are able to survive. The strong and fittest species are the "selected ones" through natural selection. We can see this in many of the species which are fit for the environment and able to adapt.
An example of this fourth postulate are primates, there is a great variety of species which evolved from the primates like:
An example of this fourth postulate are primates, there is a great variety of species which evolved from the primates like:
Neanderthal
- Homo Sapiens Sapiens (Humans)
- Australopithecus
Bibliography
Buffalo State. (n.d.). Chapter 3. Darwinian Natural Selection. Buffalo State. Retrieved April 5, 2016 from <http://faculty.buffalostate.edu/penaloj/bio405/outline3.html>.
Charleswood, B. (2009, November 1). Darwin and Genetics | Genetics. Retrieved April 04, 2016, from http://www.genetics.org/content/183/3/757
University of Evansville faculty. (n.d.). Natural Selection. University of Evansville. Retrieved April 5, 2016 from <http://faculty.evansville.edu/de3/b32003/lecture%20summaries/selection.pdf>.
Charleswood, B. (2009, November 1). Darwin and Genetics | Genetics. Retrieved April 04, 2016, from http://www.genetics.org/content/183/3/757
University of Evansville faculty. (n.d.). Natural Selection. University of Evansville. Retrieved April 5, 2016 from <http://faculty.evansville.edu/de3/b32003/lecture%20summaries/selection.pdf>.