Charles Darwin's Four Postulates
Theory of Evolution
Charles Darwin's Four Proposed Mechanism for Evolution.
- The possibility for a species to increase in number.
- Genetic variation of species are due to mutation and sexual reproduction.
- Competition for resources.
- Natural selection of organisms which adapt better to their given environment.
Genetic Variation
The Galapagos finches are birds from the same family whose beaks vary in sized depending on the environment of their islands.
Population Growth & Competition For Resources
Ex.
Rabbits were introduced to a foreign environment and they began to bred out of control. Humans tried to fix it by introducing cats in order to kill off the rabbits. The only thing that this caused was species to compete for resources because they became predators for the same local species.
Natural Selection
Sharks are coloured white on the bottom and blue on the top. This works to camouflage the organism because when looking down the shark blends with the colour of the ocean and when looking up it blends with the light coming from above.
What It Actually Means
Population Growth
Population growth takes places because species produce more offspring because not all offspring will survive. There are many environmental, human and genetic factors that affect the outcomes.
Genetic Variation
Genetic Variation is found within populations where organisms express individual variation in behaviour and appearance. These variations include body size, hair colour, number of offspring, markings and voice properties.
Competition For Resources
Natural Selection
Bibliography
Beldade, P., & Brakefield, P. (2002, January). Plasticity in wing-pattern development. Retrieved April 06, 2016, from
http://www.nature.com/nrg/journal/v3/n6/box/nrg818_BX3.html
Cronin, J. P., & Carson, W. P. (n.d.). Competition. Retrieved April 06, 2016, from
http://www.biologyreference.com/Ce-Co/Competition.html
Earth Watch Institute. (n.d.) Darwin's Finches and Natural Selection in the Galapagos. Retrieved April 06, 2016, from
http://earthwatch.org/expeditions/darwins-finches-and-natural-selection-in-the-galapagos
YourDictionary. (n.d.) Examples of Natural Selection. Retrieved April 6th, 2016, from http://examples.yourdictionary.com/examples-of-natural-selection.html
Hoang, L. N. (2012). Darwin’s Theory of Evolution. Retrieved April 06, 2016,
from http://www.science4all.org/article/darwins-theory-of-evolution/