Not different but Mass Effect 3 war assets there are more human assets instead of council races.

You don't see any of the human councilors in ME2 other than Anderson or Udina, and in ME3 they are replaced by the same alien councilors that would replace the old ones if the Destiny Ascension was destroyed but humanity does not take over completely.

There can be an all human council?? How do the other races let that happen?

There never is an all human Council. If you choose to not save the destiny ship the original councilors die leaving a gap in power. Udina or Anderson take up the reins and humans get an upper hand in Galactic power and end up having the strongest military fleet for a time but each Council race votes in new councilors.

As for what happens, different dialogue with Anderson if you visit in Me2 and a turian shop keeper speaks to you with disgust but not much else.

If you complete Mass Effect as a Renegade, allow the Destiny Ascension to be destroyed, and endorse Ambassador Udina as Chairman of the new Council, he declares that it will be an all-human Council, which is confirmed in epilogue text. However, 2 years later (i.e. by the time you can return to the Citadel in Mass Effect 2), the other human councillors will have been replaced by Asari, Turian, and Salarian councillors.

If you are Paragon, allow the Destiny Ascension to be destroyed, and endorse Ambassador Udina as Chairperson of the new Council, he will begrudgingly allow the other 3 races to remain on the Council, but use his position to push through various pro-human policies.

Regardless of whether you are Paragon or Renegade, Captain Anderson remains a decent person.