Answer:
Phenotype
Explanation:
It's phenotype because a genotype is not a physical trait; a genotype means genes. It's phenotype because it a physical trait you can see. Lets say twins look the same on the outside but on the inside they have completely DNA. This is like how some butterflies look the same with orange wings but one might have a mutation in its genes.
Answer: They compare the number of mutations to determine how long ago species separated and evolved.
You're welcome!
That would be a hypothesis
Hope this helps you :)))