If there are 2 species that have evolved from one specie, the they very well can occupy the same ecological niche, and since evolution take a long time, there is a possibility of a large distance gap...
The two values are equivalent in that they both represent around 4/10ths. However, 0.40 has one more significant figure, making it more precise than 0.4. Do not confuse "equivalent" with "equal",...