L5 - Lecture #5 Chapter 6: Principles of Ecology -...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture #5 Chapter 6: Principles of Ecology - Self-sustaining Mechanisms in Ecosystems Homeostasis 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Like organisms, ecosystems possess many mechanisms that either resist change or help them recover from change. These mechanisms help keep natural systems in a state of relative constancy. The Resilience of Ecosystems In ecosystems, changes in biotic and abiotic conditions lead to a cascade of effects, but the systems tend to return to normal over time. The ability to resist change is called resilience. Species Diversity and Stability Ecologists still debate the reasons why some ecosystems are stable and some are not. We do know that reductions In species diversity can Destabilize ecosystems 6.2 Natural Succession: Establishing Life on Lifeless Ground Ecosystems can form on barren or relatively lifeless ground by a process called natural succession. Evolution by Natural Selection Natural selection is the driving force behind evolution. It consists of natural forces that select for those members of a population that are superior in one or more features. These advantages increase chances of surviving and reproducing. Natural selection weeds out the less fit organisms of a population, leaving behind the fittest.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/03/2009 for the course GEOS 105 taught by Professor Staff during the Spring '08 term at Texas A&M.

Page1 / 4

L5 - Lecture #5 Chapter 6: Principles of Ecology -...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online