Theories of Biology

Evolution by Natural Selection

Evolution is widely viewed as the foundational theory of biology. There are two parts to the theory of evolution. The first part establishes that species can evolve over time. The second part states that this evolving is accomplished through natural selection.

Shop Amazon – Used Textbooks – Save up to 90%


Inheritance is a theory which predicts that traits and characteristics are passed down from one generation to the next through the use of genes.


The theory of cells is the theory that cells embody the smallest form of life and that organism is composed of cells. Also stated in this theory is the idea that all cells come from other cells, rather than from non-biological matter.

Biological Classification

Biological classification is how scientists organize the diverse biological spectrum found on earth. After the adoption of evolution after Darwin, this classification system turned more to genetic divergence rather than form and shape.


This theory explains how energy is replicated in biological systems.


This theory explains that organisms retain precise internal conditions through different means.


The theory of ecosystems deals with the inter-relatedness of both biological and non-biological systems in a particular environment. The theory basically espouses that everything in a biological system interacts with everything else.

Get up to 80% Off Textbooks at Barnes & Noble

Relevance in the News

CNN recently launched a special called “Planet in Peril”. The program highlighted some of the main ways in which humans are negatively impacting the earth. One specific interest was natural gas drilling in Wyoming (Fantz, 2007). Apparently, the drill rigs have upset the delicate ecosystem of the mule deer and grouse populations in those regions. The power lines used to keep the rigs going are ideal perches for the grouse’s predator, the raptor. Also, the drill rigs limit the amount of sagebrush that can grow, which is the main source of food for both the mule deer and the grouse.   


Fantz, A. (2007, July 25). Energy, wealth and wildlife: Wyoming looks for harmony. Retrieved January 2, 2008, from science/07/24/gas.wildlife.wyoming/index.html

Checkpoint Topic

Review Ch. 1 (pp. 10-11) of the text.

  • Post a 200- to 300-word response to the following: In your own words, summarize each of the major theories of biology.
  • Choose one theory and give an example of how this theory is relevant in the news today.
  • Use at least one outside reference in addition to your text.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Powered by

Up ↑

%d bloggers like this: