If the only goal of evolution is for an organism to survive and reproduce in its environment better why have organisms...

If the only goal of evolution is for an organism to survive and reproduce in its environment better why have organisms become so much more complex over time? Can anyone really make the case that complex organisms humans are better fit to survive their environment than bacteria and other prokaryotes?

*complex organisms such as humans
Sorry about that.

Competition from limited resources.

Complexity arises from biotic stress, e.g. competition between organisms. Limited resources "force" organisms to use same resources more optimally or find new resources. Finding new resources and new ecological niches requires often more complex behavior than just reproducing every 20 minutes.

A two-trick pony is more likely to gain more resources than a one-trick pony. A three-trick pony will beat them both at gaining resources. Increasing the organism's ability to make more complex structures and functions demands cooperation between cells, and that's why multicellular organisms evolved.

Bacteria and humans have different ecological niches, and are both as "optimal" in these niches as they currently can.

Selection pressure resulting from limited resources opening up niches for novel and ultimately more complex organic structures to develop.

Evolution is the name for the process where change results from genetic changes in successive generations. It does not have a goal. Stop making this error.

Fitness in the evolutionary context is a term applied retroactively to those organisms that have passed on their genes. Whatever you are trying to suggest with the second question is unscientific.

>Can anyone really make the case that complex organisms humans are better fit to survive their environment than bacteria and other prokaryotes?
I think E.D. Cope made that case in the 1800's.

Surprisingly enough organisms that are larger than the rest have an easier time getting food and avoiding predators. Larger is generally more complex.

It's weird.

>why have organisms become so much more complex over time?
They haven't, or at least not the way you're thinking. Single-celled organisms really ARE the most successful on the planet. Their diversity and populations are ridiculous.

Contrary to what you might think, evolutionary branches can tend to become more complex or simpler over time. Or, larger or smaller. One way or the other, if it happens to increase survival odds, it will tend to stick. That is all.

There is no overarching trend to prefer one over the other. If anything, simple organisms are probably preferred, as shown by the success of bacteria, etc. More minimalist structures are more efficient, perhaps.

An average increase in "complexity" (whatever that even means) over time only seems apparent because there is no other "direction" to evolve in. Organisms can only be so simple. They can't randomly mutate to not have a membrane and expect to survive. So even with a perfectly random system, some increase in complexity will happen to arise over time.

Complexity accumulates mostly because its just a fact of biological mechanisms that its "easier" to add things than to take them away

Evolution doesn't reward the best/most efficient organism. It rewards what works. What eventually became human worked (for a while), and since then, human has worked.

What is the "reward" for being alive in a way that you leave something behind for a human to say you existed?

>goal of evolution
teleology is dead, give it up Lamarck

This, combined with ever changing environments.

Ever heard of specialization, speciation and niche partitioning?

>They haven't, or at least not the way you're thinking
Uh... yes they have. A snail, for example, is physiologically and anatomically far more complex than a single-celled organism.

>If the only goal of evolution is for an organism to survive and reproduce in its environment better
That isn't the goal of evolution. Organisms surviving while others die is the reason evolution is a thing.

But the vast majority of organisms are less complex than a snail.

There is no goal of evolution, whatever survives to pass on its genes has those genes continue on. The more complex organisms happened to survive and pass on their genes.

>The more complex organisms happened to survive and pass on their genes.

>animals adapt to survive in their environment
>Humans become their own environment and have to adapt to humans
>Adapted humans have to adapt to the new adaptations

And it's not like there's fucking rules too it, if a fucked up mutant survived then it did, it doesn't have to be something special or a funny coincidence or "if it wasn't for this this and this happening, life as we know it would cease to exist" shit

Natural selection is not the only driving force in evolution. Other factors such as genetic drift (random sampling of alleles from generation to generation) can have an effect. There's already been mechanisms proposed for how genetic drift of selectively neutral mutations may lead to the evolution of greater complexity in small molecular machines (Doolittle et al. 2012 a ratchet for protein complexity). Still lots to learn though

It's all about information processing.

If an animal is hungry it hunts something. The problem is, that this information "how" to hunt something get's erased each generation (because animal die) which leads to "instincts". They do the work for you without even thinking.

But. After the birth of the human language we can "save" information. We can write books, we can tell our children "tips" to hunt etc. This means, we can save information even beyond generations which made us an more complex organism.

This is just an analogy but yeah that's the point. The more complex (and intelligent) an organism is, the better it can process information and the better it can adjust to given information (e.g. change of nature etc)

>OP thinks he's more complex than a bacteria