What does the diversity in morphology (elliptical vs. spiral) among red galaxies suggest about their evolutionary paths?

Answer

There are multiple, staggered evolutionary tracks leading to a mature, quiescent state.

The variation in structure among red galaxies indicates that the mechanism leading to the cessation of star production is not singular; different physical causes result in different evolutionary outcomes.

What does the diversity in morphology (elliptical vs. spiral) among red galaxies suggest about their evolutionary paths?
galaxiesastronomyredshift