The four buttons "X+", "X-", "Y+" and "Y-" on the bottom button bar change the number of rows and columns in the pattern array.
"X+" adds a column.
"Y+" adds a row.
"X-" removes a column.
"Y-" removes a row.
You can't reduce the number of rows or columns below 1.
You can explore pattern space by clicking the right mouse button over the pattern you find most interesting. All the other patterns are replaced with mutant copies of the one you clicked on.
Pressing the "Evolve" button on the bottom button bar creates mutant copies of the one in the top left corner. If there is only one pattern then it is replaced with a mutant copy of itself.
If you double click the left mouse over a pattern it will grow to occupy the full space. The other patterns are lost. You can then use "X+" and "Y+" to increase the number of cells again and restart evolving
If you feel you are in an evolutionary dead end the "Restart" button will create a new random pattern for you to start again.