How to easily change Sort Order

I'd like to have the most recent photos at the top of my gallery. I'm not sure how to do this. Here is the call that I'm using:

[[Gallery? &album=`Life Illuminations` &plugin=`slimbox` &thumbWidth=`200` &thumbHeight=`200`]]

Can I just add &sort=`ascending` or &sort=`descending` or something like that? I don't see it mentioned anywhere.

Any help would be appreciated.

sort The field to sort images by. You can use "rand" to make a random sort.
dir The direction to sort images by.

I'm not exactly sure what "fields" you can use.

Thanks Susan. That helps.