Big Bang theorists, can you prove that redshift isn't just turtles from other galaxies are walking away?

Unfortunately spectral evidence from the red shifted galaxies shows their composition to be largely hydrogen and helium--with the turtles one would expect vast amounts of long chain carbons to show up in the spectra--the only carbon in the spectra from distant galaxies is very small molecules like formaldehye, carbon monoxide. Turtle theory crushed by scientific methodology.