The “strengths and weaknesses” people say nothing about the Cambrian containing fish or mammals. They say that basically all of the different “body structures” or plans quickly came into the fossil record.
And this is not true. Because birds, for example, have a common "body structure" which does not appear in the Cambrian.
You are entirely correct. Both the “phyletic gradualism” and the “punctuated equilibrium” trees should show these “deepest taxonomic divisions” coming into existence suddenly during the Cambrian explosion. The problem is that neither theory explains why these divisions come into existence in the first place. That is the point! It is a major unanswered question!
Huh?
By a little process we call "evolution". One species splits off from another species. Look at the diagrams.
When it happens, the production of phyla looks like speciation (which it is) there's nothing special about it except in retrospect.
Since you are contradicting me and my sources, I suggest that you provide the evidence showing this "common ancestry."
The fossils are too scanty to trace any particular line of descent, but there are certainly fairly undifferentiated bilaterians in the Precambrian. To go better than that, we require the techniques of molecular phylogeny.
You have given nothing in this post to indicate anyone is being bamboozled other than children and yourself ...
... and all those scientists who've spent their lifetimes studying a subject of which you have just begun to scratch the surface based on your acquaintance with inaccurate children's textbooks.
They are being taught as scientific fact something that lacks support in the fossil record.
They are being taught
lots of things as scientific fact that are not supported in the fossil record. Such as that the Sun is hot.
The fossil record does not support the traditional “tree of life.” If you believe that it does then provide the evidence.
The fossil record also does not
contradict the "tree of life". The fact that it does not allow us to confirm every detail of it
from the fossils alone would be of significance only if the tree of life was meant to be constructed based on the fossils alone, rather than on
all the evidence, such as morphology and genetics.
By pretending that it is, or that it should be, based on only a proportion, sometimes quite a small proportion, of the evidence, creationists have managed to obscure their own understanding of biology, without, of course, making the slightest impression on scientists, who know better.
If we were to draw the tree of life based solely on fossils, we should have to leave off entirely at least seven (I'm still counting) of the 36 living animal phyla, because there are
no fossils of these phyla, in the Cambrian or anywhere else!
Edited by Dr Adequate, : No reason given.
Edited by Dr Adequate, : No reason given.