Basic Evolution

strubenuff · #1 28th November 2003, 11:00 PM

This may be a misconception on my point, but I've always understood survival of the fittest to mean that the smartest, fastest, strongest, etc. version of species survives and overcomes the dumber, slower, weaker, etc. version of its species. I don't understand why there seems to be such a focus on these beneficial mutations, when simply having more sex produces the same result. There need be no correlation between positive mutations and an evolutionary outcome. For example, let's say finch x has a smaller, and therefor less useful beak, than finch y. How do we know finch x won't simply produce more offspring then finch y, and eventually replace it as the dominant type? Or, just in general, some creature less able to survive then its counterparts produces more offspring to counteract this, and eventually becomes dominant. In my mind, it doesn't follow that some slight advantage via mutation will mean that one produces more viable offspring than the other. Because that's what it comes down to, right? So long as one is able to produce viable offspring (offspring that will in turn live to propagate), one could end up on top in the evolutionary pyramid. Thoughts?

Pete Harcoff · #2 28th November 2003, 11:05 PM

Using your finch example, you can't ignore competition for resources. A finch with a larger beak might be more adept at getting food, thereby reducing the amount of food available for smaller beaked finches. Therefore, smaller beaked finches would have a greater chance of starvation, poor health and possibly death, and there would be a gravitation towards larger beaked finches.

strubenuff · #3 28th November 2003, 11:13 PM

Perhaps it was a bad exmaple. Why can't the finch with the longer beak survive with the smaller beaked finch? The finch with the smaller beak is able to get food, and the finch with the longer beak is able to obtain more (because it has a larger beak). Why must these finches with smaller beaks die or starve? Why aren't they eating all the food that a small beak can reach? Why aren't they producing just as much, or more, offspring?

Ryder · #4 28th November 2003, 11:14 PM

The theory of evolution posits that these little changes will give one species a better chance of reaching maturity and producing offspring, but yeah, since those changes are supposed to be so small I don't see why they'd change the population layout either. The crunch the evolutionists face is that they can't make the changes to small, or else you get this problem of why they'd shift populations at all, but they can't make the changes to big either, else you get the 'uh huh, God didn't do it but you expect us to believe that a random mutation just added a whole micro-organelle, sure...' problem. The changes have to be small enough to be plausible, but large enough to appear to have any real effect. Pointless debate really, since evolution cannot be demonstrated to exist. Sure, religion takes faith, but evolution is often presented as the scientific answers outside of faith and the theory still eludes facts and demonstration, go figure.

Good question Strubenuff!

notto · #5 28th November 2003, 11:16 PM

When there isn't enough food to go around, competition will drive evolution and some species will go extinct.

As far as eating different foods, that is exactly what Darwin observed on the islands he visited. Several different beaks that were good at getting different kinds of food.

If the populations can evolve to get new food sources where there is less competition, they will survive. If they do not evolve and another population out competes them for the food in their environment, they will go extinct.

Pete Harcoff · #6 28th November 2003, 11:20 PM

Originally Posted by strubenuff

Perhaps it was a bad exmaple. Why can't the finch with the longer beak survive with the smaller beaked finch? The finch with the smaller beak is able to get food, and the finch with the longer beak is able to obtain more (because it has a larger beak). Why must these finches with smaller beaks die or starve? Why aren't they eating all the food that a small beak can reach? Why aren't they producing just as much, or more, offspring?

It all depends on the environment. If the food source is limited, then the larger beaked finch would have access to food sources out of reach compared to the smaller beaked finches. Therefore, the larger beaked finches would have a greater chance of getting a meal.

On the other hand, if the food source is plentiful enough that beak since becomes irrelevant, then there won't be a gravitation towards a specific food source.

With respect to offspring, those offspring need to eat. So if the larger beaked finches are more able to obtain food, then there is a greater chance their offspring will survive to reproduce.

notto · #7 28th November 2003, 11:20 PM

Originally Posted by Ryder

The theory of evolution posits that these little changes will give one species a better chance of reaching maturity and producing offspring, but yeah, since those changes are supposed to be so small I don't see why they'd change the population layout either. The crunch the evolutionists face is that they can't make the changes to small, or else you get this problem of why they'd shift populations at all, but they can't make the changes to big either, else you get the 'uh huh, God didn't do it but you expect us to believe that a random mutation just added a whole micro-organelle, sure...' problem. The changes have to be small enough to be plausible, but large enough to appear to have any real effect. Pointless debate really, since evolution cannot be demonstrated to exist. Sure, religion takes faith, but evolution is often presented as the scientific answers outside of faith and the theory still eludes facts and demonstration, go figure.

Good question Strubenuff!

Thanks for the strawman. Would you like to discuss these issues and stick around?

Evolution has been observed. Small beneficial changes can certainly become prevalent in a population and this has been observed.

Mutation may be random, but selection isn't. It really simple logic. In a large population, there will be variation. This variation will lead to some of the population surviving better than the rest due to differences that allow them to out compete for food, mates, etc. The variations that these individuals possess, no matter how small, that gave them the advantage will be passed on to their offspring. Because they survive better, they will produce more offspring. Where is the problem with the theory?

Evolution says nothing about faith. It is sound science and can be understood and accepted by anyone regardless of their faith.

Vance · #8 28th November 2003, 11:25 PM

You have to think in larger pictures. Evolution happens in populations, not individuals. Those finches with more suitable beaks, even very slightly more suitable beaks, will TEND to live slightly longer and reproduce slightly more. Over a long enough period of time, the greater offspring by those with the "better" beaks will begin to increase exponentially (following the "he told two friends, and they told two friends, and so on . . ." principle). The next thing you know (after a few thousand years) every bird in the gene pool has the better beak. Voila!

So, no, the "smallness" of the change caused by the mutation really makes little difference. In fact, small changes are MUCH more likely that large changes, so it is more likely that the beneficial mutation for a small change will happen, then time and selection pressures do the rest.

strubenuff · #9 28th November 2003, 11:28 PM

It really simple logic. In a large population, there will be variation. This variation will lead to some of the population surviving better than the rest due to differences that allow them to out compete for food, mates, etc. The variations that these individuals possess, no matter how small, that gave them the advantage will be passed on to their offspring. Because they survive better, they will produce more offspring.

I realize I sound [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse], but I still don't see why. Take a population that is suseptible to a certain disease. It's dominant and lethal, but only shows up after they're old enough to produce. Why couldn't that population simply produce more offsping? Yes, they're going to die in larger numbers and faster than they're counterparts, but how do we know they simply won't produce more than they're counterparts? If they produce more, then the disease spreads. Though they live shorter lives, and have a harmful mutation, they're are more of them. They begin taking over the resources and the species gravitates towards being diseased.

notto · #10 28th November 2003, 11:30 PM

Originally Posted by strubenuff

I realize I sound [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse], but I still don't see why. Take a population that is suseptible to a certain disease. It's dominant and lethal, but only shows up after they're old enough to produce. Why couldn't that population simply produce more offsping? Yes, they're going to die in larger numbers and faster than they're counterparts, but how do we know they simply won't produce more than they're counterparts? If they produce more, then the disease spreads. Though they live shorter lives, and have a harmful mutation, they're are more of them. They begin taking over the resources and the species gravitates towards being diseased.

They can't just decide to have more offspring. Something would need to happen to allow them to do this. Reproduction takes energy and energy = food.

Generally, the number of offspring, is geared toward what can survive. In the example of birds,they need to be cared for. The mother can only care for so many (and even in this case, many don't survive if the brood is too large).