quote:
I know that there are many people debating if there is such thing as a "positive mutation." I have been researching this topic for only an hour for a class, and I have been able to learn only a few things, which seem to be opinions...
1.Mutations may have favorable traits but are there are never any completely positive mutations.
2.The traits of mutations may be favorable or unfavorable depending on the environment that the mutations have occurred in.
The second statement is more accurate, and it contradicts the first. Don't you think so? If fitness is relative to the environment of the organism, it's impossible to make an absolute statement about mutations being positive or negative.
The qualifier "completely" is just a way to hedge the bet if one's agenda requires maintaining that belief. Almost every trait has its drawbacks - for example, large human brains drastically increase our energy requirements. We would be, in many ways, better off without them. Despite this, the fossil record shows that their size has increased steadily. The benefits outweight the cost.
If you want more short-term, observable examples of positive mutations, there are some that have occurred in your lifetime (or at least the lifetimes of the old farts here
). One of the best examples of positive mutation is a type of bacterium observed in Japan that feeds off waste from the production of nylon. This race thrives in an environment that didn't exist a few decades ago, due to a mutation that allows them to digest the waste. We can also do experiments with bacteria where they mutate over generations and develop resistance to parasites or toxins.
[This message has been edited by zephyr, 09-06-2003]
™ Version 4.2