RTB: Scientists are now coming to understand what critics of Neo-Darwinian evolution have been shouting for decades: Evolution is no accidental process of gene shuffling, but rather a fast, adaptive, environmentally-driven process.
This process most likely involves all of the retroids, retroviruses, viruses, retrotransposons and “junk DNA” that today’s “virus researchers” mistakenly view as “invading enemies” and so target with killer drugs – which not surprisingly, kill the patient.
– “Leave my retroids alone, you animals!”
This is another link in the chain of observations forged by pioneers Barbara McClintock and Lynn Margulis, and highlights the failure of “mindless, purposeless, accidental” neo-Darwinian evolution, as popularized by snarky atheist Richard Dawkins.
These observations also highlight observations made by Janine Roberts’ in her excellent book “Fear of the Invisible.” In addition to outlining the immense failures of current virological paradigm, Roberts’ book also explores the function and meaning of viruses and related particles, and their actual use as messengers along cellular highways that serve a variety of functions, not the least of which being adaptation to stress or environmental change.
In 1971 biologists moved 5 adult pairs of Italian wall lizards from their island home of Pod Kopiste, in the South Adriatic Sea, in the South Adriatic Sea, and introduced them to the neighboring island of Pod Mrcaru….[I]ntroducing these small, green-backed lizards, Podarcis sicula, to a new environment caused them to undergo shockingly fast and large-scale evolutionary changes.
Tail clips taken for DNA analysis confirmed that the Pod Mrcaru lizards were genetically identical to the source population on Pod Kopiste. In other words, there is no doubt that these lizards are the offspring of the 1971 transplant. The results of the study were recently published in Proceedings of the National Academy of Sciences.
The lizards evolved entirely new digestive system features to cope with dietary changes, evolved bigger heads and also ceased to defend territories—an instinct once very integral to the species behavior back on their original home territory.
“Striking differences in head size and shape, increased bite strength and the development of new structures in the lizard’s digestive tracts were noted after only 36 years, which is an extremely short time scale,” remarks Duncan Irschick, a professor of biology at the University of Massachusetts Amherst.
Observed changes in head morphology were caused by adaptation to a different food source, explains Irschick. The lizards on the barren island of Pod Kopiste were well-suited to catching mobile prey, feasting mainly on insects. Life on Pod Mrcaru, where they had never lived before, offered them an abundant supply of plant foods, including the leaves and stems from native shrubs. Analysis of the stomach contents of lizards on Pod Mrcaru showed that their diet included up to two-thirds plants, depending on the season, a large increase over the population of Pod Kopiste.
“As a result, individuals on Pod Mrcaru have heads that are longer, wider and taller than those on Pod Kopiste, which translates into a big increase in bite force,” says Irschick. “Because plants are tough and fibrous, high bite forces allow the lizards to crop smaller pieces from plants, which can help them break down the indigestible cell walls.”
Examination of the lizard’s digestive tracts revealed something even more surprising. Eating more plants caused the development of new structures called cecal valves, designed to slow the passage of food by creating fermentation chambers in the gut, where microbes can break down the difficult to digest portion of plants. Cecal valves, which were found in hatchlings, juveniles and adults on Pod Mrcaru, have never been reported for this species, including the source population on Pod Kopiste.
“These structures actually occur in less than 1 percent of all known species of scaled reptiles,” says Irschick. “Our data shows that evolution of novel structures can occur on extremely short time scales. Cecal valve evolution probably went hand-in-hand with a novel association between the lizards on Pod Mrcaru and microorganisms called nematodes that break down cellulose, which were found in their hindguts.”
Change in diet also affected the population density and social structure of the Pod Mrcaru population. Because plants provide a larger and more predictable food supply, there were more lizards in a given area on Pod Mrcaru. Food was obtained through browsing rather than the active pursuit of prey, and the lizards had given up defending territories.
“What is unique about this finding is that rapid evolution can affect not only the structure and function of a species, but also influence behavioral ecology and natural history,” says Irschick.