How Evolution Can Allow for Trivial Developmental Leaps
Some evolutionary-development researchers must be taking cues from the PR team that overhyped "Ida." A recent article on ScienceDaily was titled, "How Evolution Can Allow For Large Developmental Leaps," but the article documents nothing of the kind. It begins by discussing a long-recognized problem in evolution: "when it comes to traits like the number of wings on an insect, or limbs on a primate, there is no middle ground. How are these sorts of large evolutionary leaps made?" I appreciate the author's acknowledgment that functional intermediate forms can be a problem for Darwinian evolution. I then expected the article to discuss how "large evolutionary leaps" might occur, but instead, it went on to discuss research that showed trivial biological changes in bacteria.
When the going gets tough, many bacteria will hunker down and produce spores that can house and protect a bacterium's genetic material until the environment returns to a favorable state. The ScienceDaily article reported that certain bacterial mutations may cause bacteria to produce one spore, two spores, or just die, with those traits appearing in differing proportions in bacterial populations depending on the particular mutation. Biologists were already well aware that many bacteria produce multiple spores, and at best the research shows how bacteria might produce more of something they already produce.
So what about evolving different numbers of insect legs or primate limbs? Somehow the researchers forgot to address that topic. If you're looking for "large evolutionary leaps," you won't find any here -- just bacteria that can make one spore, two spores, or die. But as Jonathan Wells showed in Icons of Evolution, it overtaxes Darwinian processes simply to produce an extra set of non-functional useless wings on fruit flies, to say nothing of producing an extra set of wings that are functional. And how about the evolutionary origin of wings or legs in the first place? It would seem that for now, the Darwinian solution to these kinds of problems exists only in the over-exaggerated titles of press releases.