chromosomal

Stick insects, Timema knulli, on a Redwood tree branch. Utah State University evolutionary geneticist Zach Gompert and colleagues studied a chromosomal inversion in the species and report findings in the June 12, 2023, online edition of PNAS. Credit: Moritz MuschickThe complexity of evolutionary processes affecting an inversion in stick insects provides resilience against loss of genetic variation, and may foster long-term survival.Genetic variation is the ultimate fuel for evolution, says Utah State University…

A new study used a unique approach based on chromosome structure to determine that comb jellies, also known as ctenophores, were the first lineage to diverge from the animal tree of life, with sponges following as the next branch. Previously, it was unclear whether sponges or comb jellies were the first branch due to inconclusive gene sequence studies.  This research contributes to our understanding of early animal evolution and offers insight into the origin of key features of animal biology such as the nervous system,…

Just because a human egg is fertilized does not mean the embryo will survive to birth. In the first few weeks of conception, there's a whole lot that can still go wrong.When a fertilized egg first begins to divide, it must duplicate its entire genome – that's all the DNA instructions stored in the cell – so that each of the two resulting cells can receive an exact copy. This process must be immaculately repeated each time a cell divides.   But sometimes, it can miss a chromosome or make an extra copy of one.Scientists…