Asuna, let me explain to you why I believe in Evolution: 

Scientists today can date fossils using a method called carbon dating. What is carbon dating? Well you see, our atmoshpere is full of gases. One such gas is Nitrogen, and when cosmic rays and rays from the sun enter our atmosphere they interact with the Nitrogen. When these cosmic rays enter our Earths atmosphere, they produce neutrons, these neutrons then interact with the nitrogen in the air, and during this interaction a proton is often expelled.

Remember the periodic table? Well an elements atomic number is influenced by the number of protons. Well when these rays interact with the Nitrogen in our atmoshpere, they boot out a proton and the neutron is absorbed. So the element effectively goes from having 7 protons (Nitrogen) to 6 protons (Carbon; Check the periodic table). However, regular carbon has 6 protons and 6 neutrons, this newly formed carbon has 6 protons just like regular carbon, however unlike regular carbon which has 6 neutrons, carbon formed via this method has 8 neutrons. Why 8? Because remember how the element was originally Nitrogen? Well the number of protons usually equals the number of neutrons, and since Nitrogen had 7 protons, It also had 7 neutrons.

So when you have an element with 7 protons and neutrons, and you add a neutron but take away a neutron, you have 6 protons and 8 neutrons. This new element is called carbon 14 (6 protons + 8 Neutrons = 14 particles in the atomic nucleus.) Well because this element doesn't have the same number of protons and neutrons, it's unstable. Well this unstable element seeks an equilbrium through a method called Beta Decay. Beta Decay in this instance is initiated because the nucleus has too many neutrons, and not enough protons, and what Beta Decay does is, it essentially turns a neutron into a proton. So remember how we have that new special carbon 14 with 6 protons and 8 neutrons, well that carbon is seeking to turn one of those neutrons into a proton so it will return to equilibrium, in other words the Carbon 14 is decaying back into Nitrogen. 

Now, carbon 14 is being created in our atmosphere every day, and is absorbed by plants and thereby animals, and the levels of Carbon 14 in the atmosphere at any given time is the same as the levels of carbon 14 in any LIVING organism, because as long as they keep living, they'll keep absorbing energy and thereby keeping thier levels of carbon 14 equal to that of the atmosphere. Now when an organism dies, it ceases to absorb carbon 14, so the amount of carbon 14 in the specimen at that time becomes finite (or limited). Now why is any of this important? Because we know all organisms have carbon 14, and we know carbon 14 decays. Well also know the rate at which carbon 14 decays. This rate is called a half life. 

A half life is the amount of time it takes for a substance to decay into half the amount that was previously. To put this in terms of percents and fractions, let's say right now since your alive you have all of your carbon 14 still, well that fraction can be written as 1/1 (or 100%), since you have ALL of your carbon 14. Now let's say one half life passes, all you do is multiply that bottom number by two, so you end up with 1/2. So after one half-life, you have HALF the carbon 14 you had when you were still alive. Now let's say a second half life passes. So now, 2 x 2 = 4, now replace the 2 in 1/2 with a 4, and you have 1/4 the Carbon 14 that you had when you were alive. What if yet another half life passes? Well 2 x 4 = 8, so you'll have 1/8 of your original carbon 14 after 3 half-life(s) have passed. 

 Why does this matter? Because we can measure the rate at which carbon-14 half lifes occur, and carbon-14 has a half life of roughly 5,500 years. Meaning each half-life = 5,500 years. So when scientists discover a fossil, and measure the amount of carbon-14 inside, they are carbon-dating the fossil to discover the age of the fossil. Other methods of dating can be used, such as potassium or argon dating, which have longer half-lifes to allow us to measure the age of much older fossils or rocks. These methods have been used to date rocks up to 4 billion years old! Now these methods of dating are not only accurate, but more importantly they can be tested, held up to scrutiny, and still pass! 

So now we have carbon dating, which can tell us how old objects are. Well let's use carbon dating in conjuction with prehistoric fossils, in this case we'll use the Homo Genus as examples. Homo is the name for our genus, the human genus. 

Now let's go back in time. Before humans, modern chips and gorillas evolved. At one point in time, all of these animals shared a common ancestor, or a species that would in time evolve and diverge into three different species. While which species is our last common ancestor isn't known for sure, we've found an extensive list of fossils that link us to the past. The Orrorin tugenensis is an early species of Homininae (that is a sub-family of hominidae that includes gorillas, humans and chimps) that was discovered in 2000, and has been dated to have lived roughly 6 million years ago. 

 Now, as time passes and Orrorin tugenensis faces different environmental pressures and genetic mutations, the species changes. Think of it as a family tree. You start at the base, in this case the Orrorin tugenensis, and as time passes the tree grows and branches out. Some branches don't work, or don't reproduce, so they end. While other branches thrive and reproduce, so they continue to grow. Well one branch of the tree grows and becomes chimps, another branch grows and becomes apes, while yet another branch grows and becomes humans. Now, it might be hard to imagine that a single species evolves into three different species, but when you consider that not only did all of this happen over the course of thousands of years, but also countless species existed between point A and point B, most of which went extinct, then you'll see that this change was VERY VERY gradual. 

 So eventually, and i'm making a huge jump here, but we end up with Homo Erectus. Now take a look at this image:

[img]http://upload.wikimedia.org/wikipedia/commons/1/15/Homo-Stammbaum%2C_Version_Stringer.jpg[/img]

Do you see how Homo Erectus diverges? Homo Antecessor and Homo Heidel not only evolve from homo Heidel, but they also lived alongside them! But do you see how eventually Erectus and Antecessor stop? That means means those species went extict, in other words those branches ended there. Yet Homo Heidel continued to evolve, or change over the course of many years. Eventually you see that branch splits yet again into Homo Sapiens and Homo Neanderthalensis, But do you see how those branches grow into Homo Sapiens?

Well it's theorized that Homo Sapiens were smarter then the other Homo Species that they lived alongside, and competed for resources. Over many thousands of years, Homo Sapiens either interbred with the other species of Homo or out-competed them for resources, so you are left with only Homo Sapiens, or us! 

 So next time you think, well if we share a common ancestor with chimps, how come we don't see other more human like species running around? Well the thing is, we used to live alongside other human species, but as it happened we kind of either bred them out or competed for resources. Remember biology class, if your teacher ever gave you a punnet square?

Well let's use flowers as an example. Let's say we have 50 yellow flowers and 50 blue flowers. Now, let's say that the genes to produce either blue or yellow are co-dominate. So Yellow and Blue flowers give you green flowers. Well, it turns out the Blue flowers are actually better at absorbing nutreiunts from the ground, so as all the flowers compete for food, the blue flowers thrive while the yellow flowers begin to dwindle. Eventually, you'll have a some yellow flowers, a few green flowers, and a lot of blue flowers. Well the Blue, Yellow and green flowers continue to compete and interbred. Eventually, the yellow flowers can't keep up, so you are only left with green and blue flowers. Well as the green flowers and blue flowers reproduce, the genes for the blue flowers are added to the gene pool at a faster rate then the genes from the green flower, simply because there are more blue flowers. Eventually, the green flowers are breed out of the population. 

I completely butchered how recessive, dominant, and co-dominant genes actually work, but the principle remains true. Homo Sapiens out competed or bred out the other species of humans that were walking around during that time, and even if their offspring shared and equal amount of genes from both species, the fact that you stopped adding Neanderthal genes and kept flooding the gene pool with Homo Sapien Genes effectively meant you 'purified' the gene pool for lack of a better term. 

When you look at all the evidence backing evolution, continuing to believe in creationism seems a tad silly.