Atheists: How can you explain symbiotic relationships?

Question

There are many examples of plants and animals which have a "symbiotic" relationship (they need each other to survive). How can evolution explain this?

Answer 1

Symbiosis provides an adaptive advantage.

Edit: for both organisms.

What is so hard about this?

Answer 2

I assume they evolved to have said symbiotic relationships.

As so many others have pointed out, asking this in the religion section makes you appear to have less than sincere motives. Surely you realize that not all atheists are scientists studying the theory of evolution as well as the origins of the universe. I am a writer, and have no real reason to know the biological mechanism that provided certain animals with a symbiotic relationship.

Answer 3

All of evolutionary development is about symbiosis! Our bodies are essentially super-colonies of interdependent bacterial colonies. Without the bacteria in our intestines, we'd starve. Without specialized cells to transfer oxygen or electrical impulses, we could not breath or think. The fact that some symbiotic relationships involve distinct, complex organisms is only a matter of scale.

Each cell that developed a specialized function could survive at a primitive level. But when they combined, their function was enhance by a division of labor. Each cell no longer had to do everything. Even the components of a basic cell, mitochondria, DNA, the cell membrane, etc., had to develop independently, barely functioning until circumstances allowed them to combine into a basic organic system that could absorb nutrients, convert energy, discard waste and reproduce.

The next stage was for single cell organism to find ways to combine functions in a way that was more efficient than operating separately. In time, the symbiotic structures got more and more complex, as nutrient gathering cells got farther from the propulsion cells and a need for a distribution and communication system developed. Now the process is automated, as genes are turned on and off to facilitate the specialization that makes muscular, skeletal, vascular and nervous systems grow effectively into a coordinated whole. But each of these cells is a cell. The symbiosis is so complete that we think of ourselves as a single being, but we're really sophisticated super-colonies.

Some scientists now believe they've found the function of the appendix. Apparently it is a safe place for intestinal bacteria to survive during a cholera outbreak. Sounds symbiotic to me.

Answer 4

From Wikipedia:

Creationists have long claimed that obligate symbioses are evidence against evolution, arguing that since neither organism can survive without the other, they must have come into existence at exactly the same time. This simplistic point of view ignores the extreme variety of symbiotic relationships as well the mutability of species over time. Obligate mutualisms could easily evolve from facultative relationships in which neither species is fully committed. These arguments persist despite many examples of facultative symbioses and multiple theoretical and computational models describing how such a relationship would evolve.

Answer 5

If you look into early evolutionary models there are examples of algea and primitive bacteria benefiting eachover, some people would say this even lead to the creation of early cells.

It was so beneficial for some subcellular life to stay in proximity it eventually fused.

This is a pretty good link to some information about subcellular life.
http://math.ucr.edu/home/baez/subcellular.html
Knowing how much goes on at such a tiny level makes the idea of larger symbiotes seem less impressive.

That is how I think it is possible. I think it is not only possible but may explain how cellular life started.

Answer 6

I don't think that fact proves or disproves either. The evidence for evolution is not based on the symbiotic relationship between plant and animals, although certainly that relationship was a big influence in how life evolved. ~

Answer 7

Well, me not being a biologist, I can only speculate...most I can say is that they need each other to survive...other than that, I cannot answer you. Now, if you want an answer, go to the Biology section of Y!A, and if you just want your own "faith" confirmed because some of us do not have answers (since we're only human, and we don't say, "God did it!" to everything we do not understand) then continue to post these sort of questions here. Hope this helps you in some way!

Answer 8

Social evolution is still evolution. I would say that most of the species alive today have used social mechanisms to help them (as a whole) survive. Symbiosis is not a stretch from here.

Answer 9

Yeah - who would of thought that an insect would evolve to fill the niche required for the cleaning of the ears out of an Elephant.

Seriously - you think God is responsible for that?? Its a niche that was filled by that particular insect or plant. Just because they could not survive without each other NOW doesnt mean they didnt survive separately at one time in the past.

Answer 10

Plants produce food and oxygen, hence oxygen breathing animals evolved to feed on the abundance of fruit and oxygen, thus producing more CO2 which the plants need to survive.

Answer 11

I always laugh at questions like this. "Oh, this aspect of life is so incredibly complex that it MUST have been created."

But I wonder -- what process created the creator? For surely the creator would have to be so infinitely more complex than these things that are created, yes?

So the basic argument doesn't hold water.