Evolution and Myxoma Virus

Evolution and Myxoma Virus

Environmental pressures and their impact on a species

The theory of evolution states that present day organisms have developed from one or a few living organisms in the past. We can thank evolution for the diversity and extraordinary variety of life on Earth today, ranging from microscopic bacteria to the biggest whales in the sea. Earth is an ever changing place and the diversity of life is a direct result of the dynamic interplay between genetics and the environmental pressures present.

Although there is a huge range and variety of organisms on Earth, there is also a lot these organisms have in common including the substances they are made up of, the cellular structure and the use of DNA and RNA as a basic type of genetic material. Scientists say that all living organisms came from common ancestors.   All organisms have a common origin or beginning in their initial form of life, which, over time and many challenges and needs for change, has brought about the vast diversity of life, in the present day and in the past.

Environmental pressures are considered one of the major causes of change in a species. Change can take millions of years or as few as one or two years. This is clearly seen in the evolution of the European rabbit after its introduction to Australia. A rapid change in the rabbit species saw it produce offspring that were immune to the myxoma virus.


Evolution and the changing chemical environment
The first lives on earth were primitive organisms living in an environment free from oxygen. They metabolised on simple organic molecules in shallows seas and carbon dioxide was produced. Over millions of years the carbon dioxide accumulated in the environment. Some organisms evolved and multiplied through the use of carbon dioxide in photosynthesis.
Just as life altered the chemistry of the atmosphere, so too have the chemical changes impacted on evolution.   Humans change the environment rapidly and the ability of populations of...