Science, Creation & Evolutionsubstitute biology teacherI appreciate that you took the time to respond so thoroughly to my posts. It is however too bad that you have picked out excerpts from several different posts, picking out things that you thought were incorrect. I'd have to link to TO again for this one. Which you do not want to accept as a legitmate source for scientific information. (Here's the link any way: TO - Introduction to Evolutionary Biology About birds feathers having evolved from reptilian scales: This is again all theory, but sounds very accaptable to me. Animals benefit from insulation. All sorts of methods have evolved: Hair (on mammals, and also on pterosaurs - flying reptiles- ), subcutaneous fat and why not feathers as well? Let's not forget that dinosaurs lived on the southpole and near the north pole as well (although the tempertures provided sub-tropical conditions, the rain forest on the antarctic could freeze over in winter - see BBC's 'Walking with Dinosaurs' for more information about the climate on the south pole in the time of the dinosaurs.- ) Furthermore: Feathers tend to have bright colours, and reptiles have eye-sight that is quite well-adapted for distinguishing color. Early 'proto-feather' would not have been used for flight, but increased their chances of reproduction because they could be used for attracting mates. Another possibility is that they provided camouflage. It is also likely that those who had proto-feather could use them, besides any of the functions descibed above, for breaking their fall, if they lived in trees. (Information I used: http://www.dinosauria.com/jdp/buckna/five.htm ) Saying that scales are "folds in the epidermis" is perhaps too simple. www.dictionary.com has the following to say of 'scale': "One of the many small platelike dermal or epidermal structures that characteristically form the external covering of fishes, reptiles, and certain mammals." Epidermal means a layer of skin that has no veins. Feather are non-vascular 'structures' that form the external covering of birds. Is it so hard to imagine? By creating a layer of air between the dermis and the epidermis, you have an excellent method of keeping warm! In reptiles, like crocodiles and turles, we can clearly see that scales are not merely "folds in the epidermis". They make up hard ridges and even the shell of a turtle. (In the latter case, you can hardly speak of scales anymore. Apparently scales evolved into a hard, protective layer here) Yes, I can tell you what the dodo evolved from. The dodo has been identified as a type of pidgeon. Theory has it that a flock of pidgeons landed on Mauritius and two other small islands (forgot the name). It is even so that differences between the dodos on the several islands has been described (yes, variation). Evolving from a flying type of pidgeon into a flightless bird takes a lot of generation (you were right in correcting me. It's not TIME, but generations that influence evolution. And before you start on 'my e.coli have been through 2.5 million generations and have not changed a bit, I'll discuss that later. (It's getting pretty late!) Stating that 'introduction of predators' is always of great influence and should always lead to extinction doesn't hold up either. As soon as two continents drift and connect (South and North America for example) than that means there is a land bridge that allows species from both continents to interact. This does not mean all saber tooth cats are leaping the last bit onto the next continent to murder all possible prey; Many species may not even migrate out of their territory, because they have adapted to it so well. Prey animals will probably have adapted ways to evade indigenous predators and could be quite prepared for what came through modern day Mexico. In the case of the dodo, it was THE LACK OF PREDATORS, followed by the sudden introduction of them that lead to their demise. I'm off to bed. Be back soon. |
🌈Pride🌈 goeth before Destruction
When 🌈Pride🌈 cometh, then cometh Shame