Bienvenidos a la conferencia de SSR 2015 en San Juan! The theme of the meeting is Evolution of Sex and is not just the theme of the plenaries, but is key to this meeting. The newly evolved Focus Sessions span the breadth of attendee interests, and the presentations mingle invited speakers with short oral presentations. After the Focus Sessions on Friday and Saturday, the first of three innovations involving posters occur: evening poster receptions that will give attendees the chance to revisit posters, meet with speakers, and discuss all the days lectures while enjoying refreshments. The second poster innovation is the onsite organization of Topic Area neighborhoods ­dont worry: there will be maps and signs to guide you as well as color coding in this years meeting app. Finally, poster presenters were asked to record a 5-minute audio presentation and make this recording available on their poster with a QR code. Using your smart device, you can scan the QR and get direct, immediate access to the audio recording, which you can then listen to any time. These recordings will provide not only the essence of the science presented, but also give the poster authors a chance to provide additional insights into their work. Our best wishes for a great meeting here in San Juan. We look forward to seeing you, enjoying the science with you, and receiving your input on the evolution of our annual meeting.