suitability

Dr Fhionna said in an interview to Daily Mail, “We believe that the link between low stress levels in men and high attractiveness to women is because an ability to handle stressful situations suggests a strong genetic make-up, the future suitability of a partner, and their ability to pass on “good genes” to their children.”
what does means:link between low stress levels in men and high attractiveness to women is because an ability to handle stressful situations suggests a strong genetic make-up, the future suitability of a partner, and their ability to pass on “good genes” to their children

link: How stress makes us UGLY

We cannot explain the whole sentence to you. If your question is about the meaning of "suitability", as your thread title suggests, what is there that you don't understand in its dictionary definition?

pls explain the whole sentence

Women are attracted to men who exhibit low stress levels because that characteristic indicates the man has a good genetic composition. Therefore he would be a good candidate for fathering children.

It would help if you could be more specific about what you don't understand.

many many thanks