Yester-day, I realized that, provided I've figured them out correctly, the opening guitar phrases in "Every Little Thing" and Buddy Holly's "You've Got Love" have some similarity. The guitar in "You've Got Love" plays E+G#, F#+A, G#+B, and A+C#, simply ascending and then descending (with the last pair of notes played a couple times in succession). The guitar phrase in "Every Little Thing" is a bit more complex, but it too is made up of pairs of thirds that ascend and descend diatonically: A+C#, B+D, C#+E, and D+F# (not in that order).
While Buddy Holly is an acknowledged influence on the Beatles, I think this similarity is more coincidental than intentional. Still, I thought I'd note it.