Evolution

The fact that something doesn't make sense to you does not imply that it doesn't make sense. From a basic root of life, and a gradual process of improvement over billions of years, evolution easily manages to build various things for various functions in a smooth, gradual, and effective way. -- While it is true that a consequence of evolution is the requirement that each product be useful to its possessor in gradual steps from the less complex to the more complex, it isn't true that these steps are hard to make. You suggest that the eye has a "minor argument about light-sensitive patches" however that's not a minor argument that's the explanation. The evolution of the eye is well known and well understood and light sensitive patches of skin are simply nerves and pigment which do occur quite easily and commonly. Even without our eyes it's common to feel sunlight on your neck. You suggest that the minimum mechanism required for detection of the direction of light is rather complicated; it is not. The minimum requirement is a slight pocketing. Light sensitive skin in a pocket gives basic directionality, further pocketing helps more, a pin hole opening is fantastic, any slightly denser material in front of the hole will cause a slight lensing effect. The eye is easily produced from gradual steps each being useful to it's possessor and each being trivially produced by little random changes and maintained by the struggle of life. The eye is actually one of the easier structure and best understood structures to evolve. Although, each step must be useful it doesn't hold that each step is the best step. The mammalian eye is flawed in a number of ways due to the gradual mindlessness of evolution. In mammals the ganglia are backwards and the blood and nerves which serve the eyes erupt from the light side of the cells and run across the visual centers, they enter the eye in the middle, which causes us to have a blind spot which we compensate for by hallucinating. This would be like running all the wiring for a video camera across the lens and having a gaping hole where they all connect to the camera. And worst of all, it doesn't have to be that way. Squid eyes are constructed properly without need for a large series of adaptations to work around a problem that a three year old would have avoided. DNA doesn't help the evolution process, it's a product of evolution itself and serves as a library of different proteins and enzymes. Most evolution occurs in the expression of genes rather than creation of new novel genes from scratch. It's believed that the lens of the mammalian eye is actually just a different expression of a gene which already existed elsewhere. Similarly genes are copied and tweaked by evolution. Those changes which help are passed on to the rest of the species when the organisms possessing them utilize their slight edge in the struggle for survival over several generations. Most difficulty understanding how DNA has the flexibility to create structures is naivete about developmental biology and genetics. -- Which isn't limited to simply the non-biologists, it often surprises the biologists themselves. You seem to suggest that such changes would need to "move as a group" or have the "same thing happening to a lot of members of the species at once" -- I must single this statement out as overly wrong. Such slight edges need only occur in one organism at any one time and pass to the rest of the species in successive generations. Somehow you seem to forget that mutations can be passed to ones children. The eye however has evolved about 20 times, on roughly similar paths. http://www.youtube.com... Most vertebrates have the same evolved eye with slightly different configurations, from the same ancestral vertebrate fish. Insects similarly have compound eyes which too shares an ancestral link with our eye triggered by the same hox gene (called eyeless) for eye production. Your suggestions here seem to be that because common ancestors exist and most creatures get their eyes from this common ancestor that something magical is happening. Most animals have teeth, bones, legs, etc which are also modified versions of the same common ancestor's form, are these too impossible? "If you see something which is vaguely the same colour as its background, you can still pick it out without difficulty, so why does having partial camouflage help in survival?" Because if being the same color as the background causes you to die 1% less often than the other members of your species that is a massive edge in the struggle for survival. It isn't that you can still pick it out, but rather that you could pick it out much more easily if it weren't the same color as it's surroundings. Slight edges in the struggle for survival make massive differences for members of those species. "Also, the human kneecap. It protects the joint, yes, but what help would a small sliver of bone be, that caused it to evolve?" http://www.ejbjs.org... The patella didn't evolve as a bone it evolved as a tendon and ossified in the common ancestor of the placental mammals (marsupials have a non-ossified patella). It serves the same purpose as other tendons but expressing the gene for bone makes the cap able to protect the joint. We can see that this is the evolutionary route taken because developmentally the ossification (boning) of the tendon occurs between 2 and 6. Babies don't have the bone, it forms later. This is what we should expect for a process which builds gradual changes on to previous designs. There is no small sliver of worthless bone that develops into a robust kneecap, there's tendon that gets hard. DNA evolved from RNA. Further we find that we can create the basic nucleotides of DNA via random chemicals in a jar type experiments. Also, small strains of DNA have crystalline properties and allow for non-facilitated replication. There's a number of good starting points for abiogenesis the question we really need to answer is which served as our starting point. "The most obvious one is the evolution from reptiles to mammals. In this particular case, what on earth moved eggs to internal, live birth?" Internal gestation is a gradual process, take a look at marsupials or monotremes. Some mammals lay eggs like the platypus, whereas the marsupials have gestation pouches hatching internally then birthing into a pouch for gestation. From there it's a small jump to full gestation internally. Bioluminescence develops in a number of species and doesn't need to serve as bait, it works perfectly well for a number of purposes. Birds themselves incubate their eggs, strategies to keep the eggs warmer allows for more and more additional time to forage. The Bombardier beetle's chemicals are similar to those of less noxious related beetles to serve the same purpose. There's every reason to suppose that the formula used evolved from similar less noxious substances. Also, the individual components are pretty nasty on their own. --- In all of your "questions" the answer is the same. How did it evolve? Gradually in conjunction with the other factors. Also these are all arguments from ignorance. Evolution can't work because I don't know how *THIS* could have formed. How can evolution be true of some small minutia of method is failed to be grasped by you? That's certainly some crazy sort of hubris. Also, you never responded once to all the positive evidence for evolution or to my very well made point about the necessity of improvement given the struggle for survival. Beyond the fact that evolution serves as a well rounded and robust explanation for all the species on the planets it also is necessitated by the simple factors of the struggle for existence and heredity. If you are rerolling the die with the lowest value, your total value is going to increase. http://www.talkorigins.org...