Elliptical galaxy ESO 306-17 looks rather pretty in this Hubble Space Telescope image (count how many other galaxies there are in the background!). However beautiful though it may be, this galaxy could be a ravenous cannibal! ESO 306-17 is isolated in the intergalactic void possibly because it has swallowed up all its smaller neighbouring galaxies.
Increasingly astronomers are becoming aware of the fact that larger galaxies absorb smaller galaxies. Our own Milky way seems to have done this many times. Billions of years from now the Milky way will itself be consumed by M31, the Andromeda Galaxy and its meal eventually forming a vast elliptical called dubbed ‘Milkomeda’ (surely we can think of something better than that!) Over a vastly longer time-scale, perhaps 500 billion years, all the 35 or so galaxies in the Local Group will merge under the influence of that all-conquering king, gravity.
ESO 306-17 lies about 500 million light years from our current position, so we are seeing it as it was about the time of the ‘Cambrian Explosion’ when animals (albeit only worms, molluscs and arthropods) overtook specks and blobs of jelly as dominant lifeforms in the seas of Earth.