  Dwarf irregular galaxies appear to have undergone very slow chemical
evolution since they have low nebular abundances, but have had ongoing star
formation over the past 15 Gyr. They are too distant for red giant abundance
analyses to examine the details of their chemical evolution, however the
isolated, bright blue supergiants do allow us to determine their present-day
iron abundances to compare with both stellar and nebular alpha-element results.
The [alpha/Fe] ratios in four Local Group dwarf irregular galaxies (NGC6822,
WLM, Sextans A, and GR 8) all appear to have solar ratios regardless of the
differences in their metallicities and star formation histories. Surprisingly,
WLM's stellar metallicity is three times higher than the nebular oxygen
abundance. We compare the [alpha/Fe] ratios in the dwarf irregulars to those
from recent analyses of red giant branch stars in dwarf spheroidal galaxies,
and also to damped Ly-alpha systems, and discuss these in the context of model
predictions.
