The most logical answer that I can think from Darwin's Theory of Evolution is that that species had been isolated from other possible panthers to mate with. So after generations of that isolated group of panthers their offspring would eventually become increasingly similar.
The causes of the attractions and repulsion between molecules of water is that the oxygen and hydrogen atoms share electrons in bonds but its not equal. I hope this is the answer you are looking for! :)
Answer:
H₂ + Cl₂ ---> 2 HCl
Explanation:
It looks like the reactants are not allowed to have coefficients (not enough boxes), so you need to pick reactants and products that satisfy this condition. The only ones that appear to fit are:
H₂ + Cl₂ ---> 2 HCl