Biology evolution help!?!?!?!?!?!?!?!?!?!?

Question

I am a freshman in sophomore honors biology. My teacher is really hard and he gives these insane essay questions for us to do. I normally get them but this time i cant figure it out. "Why did the echinoderms give rise to chordates as apposed to arthropods or any other phylum." I think it is because echinoderms have an internal skeleton and their embryological development patters are deuterosomal. If someone could critique me and add some more reasons would be really great.

autloveswes,
I have a question for you. Didn't the big bang make all of teh matter in the universe? You seem to be saying that the big bang sped up evolution maybe starting the cambrian explosion. O, and something else. The essay will be on a test and the teacher wants us to go out and find things to help us to answer correctly. Thank you guys so much!1!1!1!1!1!1!1!1!11111!111!1!11

Answer 1

Although I disagree with the wording of the question that echinoderms gave rise to chordates (they share a common ancestor, being both deuterosomes), you are on the right track. Here is a website with summary information if you are allowed to use outside info for your essay:

http://www.mhhe.com/biosci/genbio/rjbiology/ELOs/ELO38.html

Answer 2

well arthropods also have exoskeleton of chitin and lack a skeletal system

oh and echinoderms are found in water so whenever something major happens (i.e. the big bang) .. they have to evolve rather quickly to survive .. we all came out of the "muck" remember .. adaptations make it possible to live on land and further the survival rate ..

Answer 3

i think it has to do with the three cell layers of their internal systems-mesoderm, etc. and how they developed into organ systems.

Answer 4

I think you're right on track.