Complicated Science

We’ve all seen the popular cartoon of evolution’s march from an ancient sea, beginning with a single floating cell that morphs into increasingly complicated creatures, on the way to the punch line of Weekend Man slumped in his armchair.
It’s just a joke, but the idea that life starts simple and gets more complex over time persists even in scientific circles. Yet one of the biggest events in evolutionary history — the origin of the cells that make up every tissue in our bodies — may be a case of life getting less complicated, according to recent research.
These types of cells are called eukaryotes, and they're found in organisms from fungi to humans. They look like the souped-up versions of simpler cells such as bacteria and their distant cousins called archaea. Many researchers think eukaryotes are the descendants of either bacteria or archaea, or some combination of the two. But genetic and protein evidence do not support this view, researchers report in Friday’s issue of the journal Science, published by AAAS, the nonprofit science society.
Instead, the data suggest that eukaryote cells with all their bells and whistles are probably as ancient as bacteria and archaea, and may have even appeared first, with bacteria and archaea appearing later as stripped-down versions of eukaryotes, according to David Penny, a molecular biologist at Massey University in New Zealand.
Penny, who worked on the research with Chuck Kurland of Sweden's Lund University and Massey University's L.J. Collins, acknowledged that the results might come as a surprise.
“We do think there is a tendency to look at evolution as progressive,” he said. “We prefer to think of evolution as backwards, sideways, and occasionally forward.”
Failure of fusion
The landscape inside a bacteria cell is pretty sparse, consisting mostly of free-floating genetic material. By contrast, the inside of a eukaryote cell is a bustling metropolis, crowded with a variety of protein factories, control rooms,...