What are the differences between positive and negative symbiosis?

Question

All I know is-

1. Positive is beneficial for both and negative is harmful for one.

2. Positive has ++ relation, negative +-.

3. The 3 types are different..

Can u guys add 2 more differences please??

Answer 1

The three types of symbiosis are more commonly called:

Mutualism (positive)

Commensalism (neutral)

Parasitism (negative)

Mutualism means that both parties benefit from the relationship.

Commensalism means that one party benefits, and the other is unaffected.

Parasitism means that one party benefits at the expense of the other.

I'm not really sure what else there is to say about symbiosis besides giving examples.

Answer 2

Mutualism has enormous impact and may be one of the stronger driving forces of evolution by acting synergistically. Sequential symbiotic relationships increase specialization and avoid conflict. Endosymbiont theory of eukarya that produced mitochondria and chloroplasts by symbiogenesis.  

http://users.rcn.com/jkimball.ma.ultrane...

http://www.isepp.org/Pages/San%20Jose%20...

Today we find plants keep their own garden. The area around plant roots, the rhizosphere, is where fungi form  mycorrhizal (literally fungi-root) relationships with the plants in all but 3 plant families. Plants could evolve better roots or rely on organisms that already have. Sharing resources increases fitness of the symbiotes in both populations.

http://www.botany.hawaii.edu/faculty/won...

Plant & pollinator mutualisms have driven the flowers into highly diverse forms and kept insects dependent on pollen and nectar as food.

Digestion by animals is dependent on gut bacteria in either  herbivores or carnivores. Bacteria break down organic like cellulose or carbohydrates into various acids that can be absorbed and processed.

Parasitism has also driven changes. The immune system exists to recognize and block ingress by foreign organisms. The immune function is to destroy invading aliens.

However the result is an eternal war of attrition with no winners. The host may develop immune responses or other mechanisms to compensate and reduce the parasite’s impact on the host population. But the greatest impact is that parasites lessen their host’s fitness.

Parasites show adaptations to their impact on the predator prey dynamic. Helminth parasites have adapted by  parasitizing the predator also. Consumed with the prey they infect the predator as their next host. This neutralizes their impact on the predator prey cycles of population increase and decrease.