Evolution Logic

First of all sorry if I put this in the wrong folder.Anyway one time I was trying to put evolution in a logical perspective. Well I was wondering why we evolve in the first place. I could think of a couple answers. They were: need, curiosity, and want for perfection, which is sort of falls into the second category.Just to be clear I want to make the distinction between microevolution and macro. microevolution can be seen in the difference between a different culture (often, but less and less as time goes on). It is defined as the changes between two animals of the same species based on different situations.Anyway, lets assume that we do it by need. Quickly you see that microevolution can take care of most of the changes we are likely to encounter i.e. climate change. But lets say that there is something that it cant take care of, lets say a flood. We wouldn't be able to get gills fast enough before we drowned.I am going to discuss the last two at the same time since I have the same argument. Lets say we were driven by one of them, both of them are driven by our brain and first when we were single cells we wouldn't be able to have curiosity and besides our consciousness cannot control the DNA. Another problem with the perfection angle is that suppose that some little part of us knows what would be better and changes us that way. How is a single celled being not as genetically good or better than us since it is more adaptable. And assuming that we are better there would be no other living thing besides us.

Thread moved here from the Proposed New Topics forum.

Let's see if I can't help answer your questions. The answer is 'need' but not necessarily in a way you might think (or maybe I'm wrong). It is 'need' in a similar way that 1 + 0.5 + 0.25 + 0.125 + ... will tend towards '2'. It's a mathematical thing (only its based around probabilities).A simple model:
If we have an environment that can sustain 100 adults and each adult can give birth to 3 infants before it dies (perhaps they are asexual). Every generation then there are 300 adolescents who are vying to be one of the 100 reproductive adults.If anyone of these adolescents has an advantage that means it is either more likely to survive to reproduce (ie be in the top 100), or has an advantage that means it (on average) gives birth to 3.1 infants, will by definition be a set of genes that is likely to reproduce, perhaps more than its competitors. Conversely 'bad' genes are likely to fall into the bottom 200 'losers'.If this kind of set up existed, then it is pretty much inevitable that the organisms will find an 'equilibrium' point to hover around where any change is going to be harmful. They will stay around this equilibrium point (in a 'stasis' of sorts) until something happens to shift what makes the genes bad or good (for example an ice age coming to a tropical zone means that thick fur becomes much more 'good' than it used to be). At this point the equilibrium point shifts and the population starts to undergo relatively rapid change until finds the new equilibrium point.And so on and so forth. Naturally this model is a simplification and I'm assuming certain things about your knowledge of evolution. If you aren't happy with some elements, let me know.Naturally the other options 'curiosity and want' are falsified for reasons you outlined.

Evolution occurs because lifeforms are imperfect replicators who sometimes die before they can reproduce.There is no 'need' for evolution, it's just something that occurs.Evolution acts on pupulations, which have no desires or curiosities.

Modulous,Just to make sure I understand you.
what you meant was, when the climate is cold, generation by generation they will get more fur by survival of the fittest, which (in your example) is microevolution. Also you were talking about microevolution*, and I was wondering about macro. I would appreciate an example of macroevolution like the above one, thanks. Lastly I'm not sure I understand your very first paragraph Chronos,
Are you saying that evolution occurs for no reason?
__since we have at least a small amount of fur on almost every part of our body*Edited by dorkfrommarn, : Including ChronosEdited by dorkfrommarn, : No reason given.

The difference between 'micro evoluiton' and 'macro-evolution' is the number of steps. The way evolution works is through many many small steps.If there is enough small steps, the change between the 'ancestors' and the 'decendants' is enough to make them new species.After all. you can not walk from Istanbul to Bagdad in a single step. It takes many many steps, but eventually, you go from one country to another.

yes but would you walk from Istanbul to Bagdad for no reason?

It's an analogy, dorkfrommarn. If the weather gradually kept getting colder and colder at Istanbul, do you think perhaps a family of foxes there might walk a little to the east - enough so that they denned up in slightly less severe winters every year? Over 500 generations, might they not be to Baghdad?

I would say that right now there is no sign that there is a reason in evolution. The walker is not heading for Bagdad, that's just where he happens to end up.

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Aslan is not a Tame Lion

Coragyps,
I understand that, I was just saying that there being no reason for evolution happening really doesn't fit in. I'm just wondering if someone could present a situation in which macroevolution would be better than micro yet still have enough time to work.

Your question doesn't make sense, dork. Micro- and Macro-evolution are not different types of evolution, such that you could choose one or another. Macroevolution results from an accumulation of microevolutionary changes.

Macro is a change outside of species, micro is change within. Although microevolution is a component part of macro, which goes out of species. When I speak of micro I am talking about below species level. So I am asking about a situation where changing from one species to another would benefit better than in-species yet still allow enough time for it to work

No, I gave the reasons why evolution occurs.

All that will happen from one generation to another are small changes. You're never going to see a "horse giving birth to a duck" type situation. If an isolated group of beavers that live in a cold environment are more likely to survive with thick fur and develop thick coats over a few thousand generations, we might classify them as a new species.For the record, scientists have documented quite a few (at least several hundred) instances of speciation/macroevolution occuring.

I'm afraid it needs a little more thinking about than that. Would that it was so straightforward. Any property change that happens to a single characteristic could be described as microevolution. Macroevolution is simply the result of property changes to multiple characteristics (the exact number is arbitrary and basically subjective). It makes simple dialogue cluttered to talk in such terms, so we concentrate on a single characteristic.That is why I stressed in my post that the model I was using for illustrative purposes was simple.The central theme of my post was aimed towards the concept of equilibrium points and stasis. When the environment changes from tropical conditions to ice age conditions, you can bet that more than a single characteristic's equilibrium point will shift. Indeed, if you want to talk in more depth we can start talking about balanced scales in many many dimensional space, but that is getting ahead of ourselves.We can see that it isn't just the equilibrium point for fur length that might change - but also for colouring, metabolism, body weight, eye sight, hearing, digestive system, circulatory system, surface area, reproductive behaviour, hunting/foraging behaviour and so on and so forth. There is another subtle thing to consider here, when all the organisms in the area start to change because of the climate, their environment changes too (because the 'landscape' of their competitors changes). This means that when equilibrium points shift it tends to be dramatic, a form of feedback can begin akin to an arms race.It gets doubly subtle when we start considering genes as the unit of selection, since now we see that their environment changes massively during these times. As far as we know it happens for no more reason that things fall when we drop them. Some people believe there is a reason for evolution, but that is belief. Edited by Modulous, : Ridding the world of redundancies one step at a time. Also, deleted a repeated point because it was redundant.