Proteins are fundamental to the structure of every organism. Proteins are formed by different combinations and sequences of amino acids, and chemistry and physics dictate what structures proteins form. This means that, in a way, proteins demonstrate the existence and consequences of order in our world.
Proteins are fundamental to the structure of, you see, every organism.
And proteins are made of amino acids and they fold into a protein.
There's, in a sense, an infinite possible number of combinations of strings of amino acids — these little balls you can put together.
There's 20 of them that are biologically relevant, but anytime you string together proteins and you put them
into, like, the aqueous environment of the cell, if they fold, they fold into only two really
stable structures. They're called alpha helices and beta sheets.
So if evolution were to run again and you had proteins they would still fold into alpha helices and beta sheets, because that's what the chemistry and physics dictates.