Where's Mario in Yoshi Legacy?

I'll be up-front about it: Mario is dead. He's been dead for a very, very long time when Yoshi Legacy: Heroes of the Mushroom Continent takes place. The feud between Peach's Kingdom and Bowser's Kingdom is a matter of history taught to young boys and girls during this time.

Most of the history in my story is rather enigmatic, especially how periods of time or events end in particular. A lot of heroes come to achieve many glorious feats, then die off mysteriously. Mario's death is very unknown, as is his brother's, princess's, and enemy's. Everyone in my series recalls that there was a great war between both of the kingdoms before they all disappeared all of a sudden, with rubble and ashes of their establishments in their place.

The many different denizens of what was once the domain of the Mushroom Kingdom soon split into many different factions and societies formed through these groups over many millenia. My story takes place roughly five thousand years after the time of the two kingdoms.

A user, DJEvans, wondered why the Yoshis in my series resembled humans quite well. Well, with the years comes a form of evolution, and Yoshis, as well as most of the other denizens, have developed the ability to speak, etc. Therefore, their overall body structure had become modified to become more able to do things that a sentient being could do, and their behavior followed suit. 

Many other things are strange about the history of my series, and for the sake of not producing an even larger brick of text, I'll end it here. Thanks for reading the entire thing, if you did. Any comments and/or thoughts appreciated.