First of all, your first paragraph has pretty glaring errors. While some fish may indeed not have boney spinal columns, many (most?) do. Per "limbs" - I think that the bottom fins found on most to all fish would qualify as limbs. That is true regardless of whatever ancestorial relationship fish may or may not have to humans.
What looks like speciation is actually many recessive genes that have all came out together.
This appears to be the key sentence in the second paragraph. Would you like to pursue this specific item as a new topic?
The third paragraph is rather muddled. The general theme is human jaw structure. Properly presented, this might also make for a new topic.
So, my impression is that in your three paragraphs you have presented a non-topic and two distinct possible topics. But the themes of paragraphs two and three do not belong in the same topic.
Please reply in this topic. Let's see if we can get something from your message 1 to work as a new topic.
Please do not propose any other new topics until we resolve the content of this one.
Adminnemooseus