Here is a paper that shows some strong evidence that the supermassive black holes in the centers of galaxies formed before the bulk of the stars in the galaxy.

Caught in the Act?

What the paper gleans from observations of very distant quasars is that the dark matter halo seems to form first, and that the SMBH forms next. Some stars form early very close to the SMBH [providing heavy elements], but there is a huge area of gas ionized by the SMBH [100,000 light years across] of unevolved gas falling into the center of the galaxy.

This is beginning to settle the matter of what came first.

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Forming opinions as we speak

The following has been excerpted from:
Caught in the Act?
Zolt´an Haiman
News and Views, Nature, 26 August 2004

Ref. 1: How does "significant" presence of heavier elements compare with that of nearby galaxies and those of intermediate age as a function of time? Has anyone constructed a profile of the gradual increase of metallicity with time? Are we avoiding concluding that metallicity is fairly constant through time which supports the theory that from a general perspective the universe is in a steady state and that some process exists (i.e., black hole disintegration or gradual but appreciable "evaporation") that recycles higher mass elements back to H and He.

Ref. 2: Isn't 100,000 light years about average for a MW-type galaxy?

Ref. 3: Two to seven thousand billion solar masses seems a bit heavier than most especially for such infants. Since only ten percent of the gas has been incorporated into the galaxies, it looks like a large portion of the dark matter is unlighted unincorporated gas.

I'm not sure how happy Occam would be of this paper's conclusion. But then speculation is lotsa fun!!

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

The metallicity of quasars is not a reflection of the metallicity of the whole universe at that time. The general presumption is that shortly after or during the formation of the supermassive black holes, that massive [100-200 solar masses] stars formed very near the SMBH from material falling in and being blown out of the SMBH. It would only take a few million years for these to start turning into type II supernovas and enriching the gas falling into the SMBH accretion disk. The relative abundance of metals seen in early quasars is consistant with this model. This article shows that the other gas in the galaxy is metal-free.

BTW, it is also assumed that SMBHs 'evaporate' much more slowly than smaller black holes. They do not recycle heavy elements into Hydrogen or Helium.
Yes, but in that era, galaxies were rarely bigger than about 10,000 LY across.
Right, that would be four to sixteen times the mass of the Milky Way, which is still small compared to the mass of Centaurus A, and the other giant ellipticals we see close by. The point of the paper is that most of the cold dark matter [representing 90% of the mass of the galaxy] was already present as a halo before the bulk of the baryonic matter [that will eventually be luminous] had a chance to begin the galactic star burst.

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Forming opinions as we speak