Which factors are most likely to affect whether a galaxy. will evolve by merging

The two factors most likely to affect whether a galaxy will evolve by merging with a second galaxy are:

1. **Its size compared to that of the other galaxy** - The gravitational influence and dynamics of the galaxies' sizes play a critical role in their potential to merge. Larger galaxies have a greater gravitational pull, which can influence interactions with smaller galaxies.

2. **Its distance from the other galaxy** - The proximity of galaxies to one another is crucial for determining whether they will interact or merge. A smaller distance increases the likelihood of gravitational attraction leading to a merger.

While the age of a galaxy and its gas content might influence effects after a merger, they are not primary factors affecting the likelihood of a merger occurring.