Explanations for the Cambrian Explosion

In an evolutionary context, an ancestor is quite literally a genetically related individual. So you should not think of ancestors as merely a group of forebears, in the sense of "the people who went before us", related or not.If you trace your ancestry and that of your third cousin twice removed, you will normally find that the both of you share two common ancestors: your great great grandfather and his wife, your great great grandmother. Your third cousin twice removed will call them great great great great grandfather and ditto grandmother - she is twice removed, hence the two extra greats. However, it could be that your great granduncle - your third cousin twice removed's great great great grandfather, but no direct ancestor of yours - is the son of your great great grandfather and his second wife. In that case you share literally only one common ancestor with your third cousin twice removed.In asexually reproducing species an organism always has one parent, one grandparent, one great grandparent, and so on. In sexually reproducing species, it is by no means guaranteed that an individual always mates with the same partner. So, although there is the possibility that two distantly related organisms share two common ancestors, it is more practical to consider just one. So, you can literally speak of just one individual common ancestor you share with the orangutan you stare in the face in the zoo. This common ancestor lived millions of years ago and was neither a human, nor an orangutan. Much much longer ago, there lived another individual animal who was the common ancestor between you and your dog. Again, this ancestor was neither a human nor a dog. The more different the two organisms under consideration are, the further back in time their common ancestor will have lived, and the less it will have looked like either of them. But every time you consider such a common ancestor, you should be aware of the fact that it must be, of necessity, literally one individual (or at most two). The phylogenetic tree is by no means the only evidence we have for the theory of evolution. All kinds of other evidence point to evolution instead of design. Besides, even the phylogenetic tree in itself is poor evidence for design. In design, if a feature does not meet requirements, it is customary to make a significant change instead of an ever so gradual movement in a certain direction. Also, we would not expect obvious mistakes, like the blind spot in the human eye, or the problematic use in bipeds of a backbone "designed" for quadrupeds, to be left untouched by a designer. That is not a conclusion, it's just a starting point of some very interesting scientific research. If you want to stop there, why would you even want to begin to investigate in the first place? If a Caucasian woman gives birth to a child with dark skin and black curly hair, I don't suppose her Caucasian husband is going to say "Well, all I can see are common parts between my child and African people. There's no reason to suspect that my wife has been unfaithful." Would you?Animal and plant breeding rely on the principle of common ancestry. If you think there was nothing to it, how do you suppose to explain its success?There will always be gaps in human knowledge, but they are getting smaller and smaller. As far as the theory of evolution is concerned, lots of corroborative evidence is available from many different disciplines. The great thing about these different lines of evidence is that they all fit with the theory, they all point to the same conclusion: evolution by random mutation and natural selection is what really happened.Edited by Parasomnium, : No reason given.

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"Ignorance more frequently begets confidence than does knowledge: it is those who know little, not those who know much, who so positively assert that this or that problem will never be solved by science." - Charles Darwin.