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Other Proof of Evolution Dead Genes: One curious tale of dead genes involves our sense of smell, or rather our poor sense of smell. In essence our sense of smell is determined by the number of olafactory receptor genes (OR). A mouse has about a thousand active OR genes, and humans have about 400. However, in total humans actually have about 800 OR genes but almost half of them are dead genes and no longer function. Dead genes are a fairly common trait in living creatures. Many human OR genes are believed to become non-functional as humans became more active in the day and began to rely on vision more than smell. Unneeded genes eventually get bumped off by mutations. Predictably, primates with color vision and hence with greater discrimination of the environment, have more dead OR genes. One of the most striking examples of the evolution of OR genes is the dolphin. Dolphins don't need to detect volatile odors in the air, since they do their business underwater, and they have a completely different set of genes for detecting waterborne chemicals. As one might predict, OR genes of dolphins are inactivated. In fact, 80 percent of them are inactivated. Hundred of them still sit silently in the dolphin genome, mute testimony of evolution. And if you look at these dead dolphin genes, you'll find that they resemble those of land mammals. This makes sense when we realize that dolphins evolved from land mammals whose OR genes became useless when they took to the water. This makes no sense at all if dolphins were specifically created. (Why Evolution is True, p 70-71,). As for dead genes, there is one other curious example. Both primates and guinea pigs have lost the ability to create vitamin C internally - the only mammals who can no longer do this. The genes for doing so are still within the human and guinea pig genome, but those genes are inactive now. They are dead. Why would a creator put a pathway for making vitamin C in all these species and then inactivate it? Wouldn't it be easier to simply omit the whole pathway from the beginning? Why do humans have thousands of dead genes in the first place? Vestigial Traits The wings of an ostrich are a vestigial trait - a feature of a species that was an adaptation in its ancestors, but that either lost its usefulness completely or, as in the ostrich, has been co-opted for new uses. (Why Evolution is True, P. 57). All flightless birds have exactly the same bones that we see in the wings of species that can fly. That's because the wings of flightless birds weren't the product of deliberate design, but of evolution from flying ancestors. It's not that vestigial traits have no function at all (ostriches still use their wing flaps as extra propulsion when running). It's because it no longer performs the function for which it evolved. Vestigial traits are also common in cave dwellers - like vestigial eyes. This includes blind crayfish, spiders, salamanders, beetles, and shrimp. Even the human appendix has nearly become vestigial since we no longer eat leaves.
Other evolutionary proof in humans includes resistance to drugs (like penicillin), color blindness, and lactose (milk) intolerance - which last only through early childhood in technologically advanced cultures, but retains it active abilities in several pastoral cultures. We can actually trace the evolutionary pathway of lactose by DNA sequencing when the tolerant allele arose by mutation. - "Why Evolution is True" (p. 217). The Sickle-cell allele found in some Africans appears to be a direct response to off-setting malaria. Animal adaptations like camouflage and mimicry are also part of evolutionary theory. Languages also show evolutionary pathways and morphological changes over time. In fact, languages evolve much like biological life forms, but unlike biology's natural selection, languages "exchange genes" all the time by bleeding into each other and combining words dialects, and sometimes new languages. Yes we use naturalism and materialism. We manage to understand the world just fine using reason and materialism. Furthermore, supernatural explanations always mean the end of inquiry.
Social evolution -
There is a lot of scientific literature on how evolution can favor
genes that lead to cooperation, altruism, and even morality.
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