I’ll just let the scientists speak for themselves.
“In the last two decades there have been dramatic changes in our understanding of how evolution works,” said Gunter Wagner, the Alison Richard Professor of Ecology and Evolutionary Biology (EEB) and senior author of the paper. “We used to believe that changes only took place through small mutations in our DNA that accumulated over time. But in this case we found a huge cut-and-paste operation that altered wide areas of the genome to create large-scale morphological change.”
Liz Liddle certainly continues to believe in “cummulative selection”, but some scientists have a differing view.
“These transposons are not genes that underwent small changes over long periods of time and eventually grew into their new role during pregnancy,” Lynch said. “They are more like prefabricated regulatory units that install themselves into a host genome, which then recycles them to carry out entirely new functions like facilitating maternal-fetal communication” Lynch said.