Rational Agnostic
Well-Known Member
I would like to present, as briefly as possible (which will probably turn out to be not very brief), what I see to be the most powerful and easy-to-understand pieces of evidence in favor of evolution. I am a layperson when it comes to biology, but it doesn't take much biological knowledge to see that the evidence for evolution is simply overwhelming, to the point where evolution can be considered a fact beyond all reasonable doubt. Many times, arguments between creationists and scientists are over minute details of the theory that do not have much meaning. However, I have never seen a creationist able to defend his/her belief in intelligent design when directly confronted with the most compelling evidence for evolution. Here are just a few of the many facts that essentially prove Darwinian evolution to be the correct explanation for the origin of species. I challenge any and all creationists to try to defend their model of intelligent design after being confronted with these facts.
1. DNA Analysis confirms Morphology with regard to the structure of phylogenetic trees: In simplest terms, analyzing the anatomical similarities between organisms leads one to believe that the organisms should be grouped together (even the Christian creationist Linnaeus recognized this). Further, these anatomical similarities suggest genetic relationship, and hence common ancestry. For instance, horses and zebras share anatomical similarities to suggest (relatively) recent common ancestry, as do humans and chimpanzees, as well as humans and bonobos. Now that we have developed the technology to directly compare DNA between species, we find that analysis of DNA confirms these similarities, and we can be assured of the genetic relationships between different animals. For instance, we now *know* that humans and chimpanzees share approximately 98% of each other's DNA, as well as humans and bonobos. Unsurprisingly, we find that animals that are more distinct anatomically turn out to be more distinct genetically as well. We can construct phylogenetic trees that map the evolutionary relationships between all organisms, and find that previous trees based upon morphology are very similar to current trees based upon DNA analysis, confirming actual genetic relationships.
2. Transitional fossils and difference in fossils in different layers of sediment--This is obviously a big one, and many creationists try to convince their followers that these fossils do not exist. However, they do exist, and they represent *tangible* evidence for evolution. They can be seen and touched. Good examples are the fossil transitions in dinosaur-to-bird evolution, as well as ape-to-human evolution. With regard to the former, we have been able to sequence fossils of dinosaurs gradually evolving feathers, wing stubs, and eventually wings, and place them in chronological order. We have done the same with ape-to-human fossils. Another point--many creationists question the dating methods with regard to fossils. Radiometric dating is reliable, but for brevity, I will not explain why this is (it can easily be googled). With regard to sediment deposition, however, it is simple to understand that the oldest layers of rock are at the bottom, and the younger layers are found on the top, as sediment continues to be deposited. No one can deny this. Repeatedly, we have confirmation that the simplest fossils are always found in the bottom layers, and the most complex fossils are always found in the upper layers of sedimentary rock, strongly indicating that the more complex fossils evolved from the simpler ancestor fossils.
3. Embryology---the development of organisms in the womb mirrors their evolutionary history, indicating that embryological developmental processes have been built upon each other. Since evolution never starts from scratch, and always builds, and improves on previous models via natural selection (among other lesser mechanisms), it makes sense. For instance, human embryos go through very stages, including those mirroring our fish-like ancestors, gradually transitioning to lizards, and eventually to more recent ancestors including apes.
4. Vestigial structures: You can easily find proof of evolution on your own body. For instance, look at your wrist. The tendon just below the wrist is a remnant from our ape-ancestors who lived in trees, and used them to aid in climbing. 10-15% of humans do not possess this tendon, but most still do, indicating our relationship with other mammals that possess it. Stronger evidence still is the existence of the phenomenon known as "goosebumps" which arise in humans when they are cold, or feeling angry, afraid, or in awe. This phenomenon is a vestigial remnant from our ancestors who had fur. These goosebumps aided them in survival, allowing them to become warmer when cold, and to appear larger when under attack (hence the reason they occur in humans as a result of fear or anger). With humans, obviously they have no effect on the appearance of physical size, but, they remain, since their is no reason for natural selection to filter them out of the gene pool. There are many, many other examples of vestiges, but I'll leave it at that.
Anyway, those our four of the strongest pieces of evidence for evolution. There are certainly others, but I think that this is probably enough. Creationists: Good luck trying to refute this. Also, I didn't proofread, and wrote this in a hurry, so if there are any grammatical errors, try to cut me some slack.
1. DNA Analysis confirms Morphology with regard to the structure of phylogenetic trees: In simplest terms, analyzing the anatomical similarities between organisms leads one to believe that the organisms should be grouped together (even the Christian creationist Linnaeus recognized this). Further, these anatomical similarities suggest genetic relationship, and hence common ancestry. For instance, horses and zebras share anatomical similarities to suggest (relatively) recent common ancestry, as do humans and chimpanzees, as well as humans and bonobos. Now that we have developed the technology to directly compare DNA between species, we find that analysis of DNA confirms these similarities, and we can be assured of the genetic relationships between different animals. For instance, we now *know* that humans and chimpanzees share approximately 98% of each other's DNA, as well as humans and bonobos. Unsurprisingly, we find that animals that are more distinct anatomically turn out to be more distinct genetically as well. We can construct phylogenetic trees that map the evolutionary relationships between all organisms, and find that previous trees based upon morphology are very similar to current trees based upon DNA analysis, confirming actual genetic relationships.
2. Transitional fossils and difference in fossils in different layers of sediment--This is obviously a big one, and many creationists try to convince their followers that these fossils do not exist. However, they do exist, and they represent *tangible* evidence for evolution. They can be seen and touched. Good examples are the fossil transitions in dinosaur-to-bird evolution, as well as ape-to-human evolution. With regard to the former, we have been able to sequence fossils of dinosaurs gradually evolving feathers, wing stubs, and eventually wings, and place them in chronological order. We have done the same with ape-to-human fossils. Another point--many creationists question the dating methods with regard to fossils. Radiometric dating is reliable, but for brevity, I will not explain why this is (it can easily be googled). With regard to sediment deposition, however, it is simple to understand that the oldest layers of rock are at the bottom, and the younger layers are found on the top, as sediment continues to be deposited. No one can deny this. Repeatedly, we have confirmation that the simplest fossils are always found in the bottom layers, and the most complex fossils are always found in the upper layers of sedimentary rock, strongly indicating that the more complex fossils evolved from the simpler ancestor fossils.
3. Embryology---the development of organisms in the womb mirrors their evolutionary history, indicating that embryological developmental processes have been built upon each other. Since evolution never starts from scratch, and always builds, and improves on previous models via natural selection (among other lesser mechanisms), it makes sense. For instance, human embryos go through very stages, including those mirroring our fish-like ancestors, gradually transitioning to lizards, and eventually to more recent ancestors including apes.
4. Vestigial structures: You can easily find proof of evolution on your own body. For instance, look at your wrist. The tendon just below the wrist is a remnant from our ape-ancestors who lived in trees, and used them to aid in climbing. 10-15% of humans do not possess this tendon, but most still do, indicating our relationship with other mammals that possess it. Stronger evidence still is the existence of the phenomenon known as "goosebumps" which arise in humans when they are cold, or feeling angry, afraid, or in awe. This phenomenon is a vestigial remnant from our ancestors who had fur. These goosebumps aided them in survival, allowing them to become warmer when cold, and to appear larger when under attack (hence the reason they occur in humans as a result of fear or anger). With humans, obviously they have no effect on the appearance of physical size, but, they remain, since their is no reason for natural selection to filter them out of the gene pool. There are many, many other examples of vestiges, but I'll leave it at that.
Anyway, those our four of the strongest pieces of evidence for evolution. There are certainly others, but I think that this is probably enough. Creationists: Good luck trying to refute this. Also, I didn't proofread, and wrote this in a hurry, so if there are any grammatical errors, try to cut me some slack.