Your point about closed systems is spot on. This is an argument of christian apologists against evolution as well: "evolution can't be true because it violates

Your point about closed systems is spot on. This is an argument of christian apologists against evolution as well: "evolution can't be true because it violates the 2nd law of thermodynamics". And this superficially apparent conflict has the same resolution: if energy can be put into a system, it absolutely can have less entropy (or more organization, or more specialization) over time.