Sexual selection is a part of evolution that favors certain traits in individuals that help attract a mate and reproduce. These can be physical features, behaviors, or genetic traits. Attractive traits lead to more successful mating and passing on of those traits, making them more common over time. This process drives the development of traits for reproductive success, not just survival. Elaborate displays and courtship rituals can be a result of sexual selection. It's an important factor in shaping the variety of life on Earth.