What do you think is the force behind evolution?

Question

What I mean is for instance; some dogs have 2 spots above their eyes that are there to look like they are awake while they are sleeping, to protect them from preditors. That's pretty smart, so what or who do you think put them there. I doubt that dogs would be capable of (over time) subconciously thinking up that kind of thing. So as an ongoing and active presence what do you think it is, if you don't belive in a God? I'm not trying to prove a point or anything, I just want to know what you think.

No, I don't mean what is the reason that they are there, that's obvious. I mean how are they there?

I'm sorry but you are all missing the point, please read my question carefully.
evidently I havn't explained it well. They are not eyebrows, and my question is not why but how. I was just using the dog as an example not the central question.

Answer 1

Hmm ... It seems that nobody has explained "natural selection" to you. That's OK (although your science teachers should be thumped).

The phrase "survival" or "survival of the fittest" is a summary of the answer.

Notice three things:
1. Not all individuals in a species are identical. This is called "variation", and it is a fact of life.
2. Individuals pass on traits to offspring. Tall people tend to have babies that grow up to be tall. Dogs with spots tend to have puppies with spots. This is called "inheritance."
3. Some traits are better for survival or mating than others.

Given those 3 (fairly self-evident) statements, we can see that those traits that happen to provide some advantage, get passed on to more offspring in the population than those traits that are a disadvantage.

So it's *on the average* in the population, that a population of *many* individuals change. And that is called evolution. Evolution ALWAYS ALWAYS ALWAYS affects *populations* over many generations ... NEVER individuals. It's not the individuals themselves (the dogs in this case) that have to think of anything ... the advantages just come *on the average* as a natural course of survival over many many generations.

As for your dog example, the question is #2. Are the locations of spots (like above the eyes) inherited? I am quite sure that the answer is no ... as far as I know a dog with certain spots on its back or face does not give birth to puppies with the same spot pattern ... but I might be wrong. So even though spots above the eyes might provide some advantage, if this trait is not inherited by puppies, then this cannot affect evolution.

(Incidentally, that is just mammals. In insects it's different. There are species of moths, for example, that have evolved spots that seem to simulate eyes, and scare away predators ... so your theory is not without merit.)

Also, with respect to #3, keep in mind that domestic dogs aren't affected much by predators. They are *far* more affected by breeding preferences by humans. So even if spots above the eyes were inherited, it would be more a fact of breeder preference that would generate more puppies with the same pattern, than any benefit against predators.

I hope that helps.

Answer 2

The father of evolutionary theory was Charles Darwin. He postulated that the driving force of change in a species was natural selection.

In natural selection, the strong survive to reproduce while the weak did not.

Traits that an organism possess by virtue of their genetics and/or mutations, can have a positive or negative effect on the organisms ability to survive long enough to pass their genes on to their offspring. Some traits are neutral and do not affect survival.

If having "spots" above their eyes kept the dogs alive while they slept by deceiving their predators into not eating them, then these dogs could then produce offspring that had these traits. Dogs without these traits could be eaten while asleep and therefore not produce puppies. Over a long period of time we find that only dogs with spots over their eyes survive. Natural selection.

Eat or be eaten.

Survivial of the fittest.

Does this answer your question?

BIOLOGY TEACHER

Answer 3

it'll more likely be a mutation that gives way to a benefit for the species. in your example, the mutation would be the spots above the eyes. mutation doesn't always mean a bad thing, just something that's radically different about one organism from the rest of the population of the same organism. one time a dog got those spots above his eyes and was able to survive better by looking like he was awake while sleeping. this gave him the advantage to breed more and spread this advantageous gene to more offspring than that of dogs without the spots. the animal kingdom is filled with these examples, but the reason for it is always survival/breeding advantages.

Answer 4

The first think to remember is that evolution is not purposive. That is, there is no goal in mind, no desired end result being worked towards. In your example of a dog (or any other animal) that has a feature that makes it look awake even when asleep, the occurence of this feature will make the animal less likely to be attacked and killed while it is most vulnerable, thus resulting in a higher likelihood of the animal surviving to reproductive age and passing on the genetic instructions for that feature to its offspring who will also benefit from the protection offered by always looking awake, thus increasing their likelihood of surviving to reproduce, and on and on. Dogs are actually an excellent example of evolution driven by selection pressures, it's just that for domestic animals the selection pressures are chosen by human beings rather than naturally occuring. Domestic dogs are gentler, smarter, and friendlier than their wild predecessors because humans chose to breed the gentle, smart, friendly ones to each other. The aggressive, dumb ones were not given the opportunity to pass on their genetic predispostion towards violence and inability to learn to their offspring. The same thing happens in nature, it's just that the selection pressure is not purposive as it is in cases of artificial selection by human beings.

Answer 5

Evolution doesn't work with subconsious thought. I'm not sure dogs "eyebrows" are there to make them look awake to their enemies, but if that is the case, they did not think it up themselves. If a few of them had some very dim spots that made them look awake while others didn't and if this did, in fact protect them from enemies, then it is simple. Those with spots lived to raise some pups and those that didn't were killed by their enemies. Next generations inherit the spots the same way you inherited brown eyes or blue eyes from your parents.

Answer 6

These dots over the eyes were passed down from previous generations due to an advage gained from having them (as you said making them appear to be awake). Now, to anwer the question of how they appeared in the first generation to pass them on... it was likely a random gene mutation. Something happened in either fertilization or production of sex cells that caused the DNA of that dog to code for the dots over the eyes. After this first dog had the dots it then passed it on to its offspring and has survived due to the advantage created.

Answer 7

What you're implying is that evolution is teleological. It is not. Evolution works through the force of natural selection.

That some dogs have spotted colors is the result of artificial selection for colors by human breeders. It has nothing to do with defense from predators.

Answer 8

Sub concious thought, or desire, has nothing to do with it. I'm interested in the dog one, never heard that before.

But, suppose, a litter of pups is born, some with spots, some without. The predator only goes for the ones without sports. Hey presto!!

Answer 9

Survival. Dogs aren't a good example because they've been bred for centuries by man.

Answer 10

Necessity of Survival.