Question

how do physical laws constrain evolution?

Answer 1

Physical constraints such as gravity limit bone density and growth and the properties of h20 constrain organisms by requiring them to have specific osmotic properties in order to function properly .

There are more physical constraints , however
most constraints on evolution are not physical , unless you count sexual selection !

I Recommend the yale open course on evolutionary bio , the prof make it fascinating and tats an understatement .

Answer 2

In the laws of pyhsics, youll probably know that the orangement of the organisms molecules, and organelles is agains the law of entropy.
our bodies are full of infomation that requires constant replenisshment,
All the order is aquired, and is retained to cercumvent the problem of everything returns to disorder.
As far as becoming more requiring energy to maintain the orderlynature of molecules and our physical bodies.