Final answer:
Galaxies from 11 billion years ago are generally smaller, bluer, with higher star formation rates, and are seen as the early seeds of today's elliptical and spiral galaxies, having evolved through merges and collisions.
Step-by-step explanation:
Galaxies that we see as they were 11 billion years ago or more, as compared to galaxies today, are generally smaller, bluer, and have higher rates of star formation. These early galaxies are observed to be much smaller on average than today's galaxies, with many not exceeding masses greater than 10¹° Msun, much less than the Milky Way, including its dark matter halo. They are also characterized by their extreme blue color, indicating a youthfulness and active star formation. Moreover, these distant galaxies appear to be fragments that eventually coalesced over time to form the larger, more massive galaxies we are familiar with in the contemporary universe.
When examining galaxies from 11 to 12 billion years ago, we are likely seeing the seeds of modern elliptical galaxies and the central bulges of spiral galaxies. This suggests a galaxy evolution process where smaller protogalactic fragments merged through collisions to produce the larger structures present now. This evolution is further evidenced by the old stars we find in the nuclear bulges of nearby spiral galaxies and in elliptical galaxies, stars that would have formed more than 11 billion years ago.