Which came first, the chicken genome or the egg genome?

Which came first, the chicken genome or the egg genome? Researchers from UC San Diego, U. of Washington School of Medicine and elsewhere have answered a similarly vexing (and far more relevant) genomic question: Which of the thousands of long stretches of repeated DNA in the human genome came first? And which are the duplicates? This work marks a significant step toward a better understanding of what genomic changes paved the way for modern humans, when these duplications occurred and what the associated costs are – in terms of susceptibility to disease-causing genetic mutations. The chicken shape in the image is actual segmental duplication data from figure 2 of the Nature Genetics paper. The egg was created with graphics editing software. Image Credit: Daniel Kane/ UC San Diego