Short answer (according to Church teachings): Evolution is a science. A homosexual act (not necessarily homosexuality itself) is a human choice.
The Church has long held that rational thought can be used to determine the natural science behind natural phenomena, as long as the teaching does not conflict with Dogma.
As far back as 1950, Pope Pius XII, in his encyclical entitled Humani Generis stated: …For these reasons the Teaching Authority of the Church does not forbid that, in conformity with the present state of human sciences and sacred theology, research and discussions, on the part of men experienced in both fields, take place with regard to the doctrine of evolution, in as far as it inquires into the origin of the human body as coming from pre-existent and living matter – for the Catholic faith obliges us to hold that souls are immediately created by God.
As far as homosexuality, Pope Francis has demonstrated an acceptance that had not been apparent at all by his predecessors. Shortly after being elected to his office, he stated: “If someone is gay and he searches for the Lord and has good will, who am I to judge?”
More recently, when discussing this statement (as reported here) he stated:
I am glad that we are talking about ‘homosexual people’ because before all else comes the individual person, in his wholeness and dignity.
@jca I’m not a Catholic clergyman, but I did study to be one. If we do have one out there in Jellyland, please correct me if I am wrong…