Elaine Meinel Supkis
I love to imagine myself as different creatures. It took several days, absorbing the essence of the newly discovered "missing link" fossil. Our delightful ancestor, the muckracker, the swamp dweller, the insect eating pioneer. Meet Tiktaalik roseae, the Large Shallow Water Fish.
By JOHN NOBLE WILFORD
Published: April 5, 2006
Scientists have discovered fossils of a 375 million-year-old fish, a large scaly creature not seen before, that they say is a long-sought "missing link" in the evolution of some fishes from water to a life walking on four limbs on land.
In addition to confirming elements of a major transition in evolution, the fossils are widely seen by scientists as a powerful rebuttal to religious creationists, who hold a literal biblical view on the origins and development of life.
Several well-preserved skeletons of the fossil fish were uncovered in sediments of former stream beds in the Canadian Arctic, 600 miles from the North Pole, it is being reported on Thursday in the journal Nature. The skeletons have the fins and scales and other attributes of a giant fish, four to nine feet long.
But on closer examination, scientists found telling anatomical traits of a transitional creature, a fish that is still a fish but exhibiting changes that anticipate the emergence of land animals — a predecessor thus of amphibians, reptiles and dinosaurs, mammals and eventually humans.
First, the head is pretty flat. Even taking into account his head being squished flat while it was being steadily fossilized. The eyes are on top. Not the sides, on top. This means, he had a tremendous interest not to the left or the right but straight up. And what was straight up?
Bugs. Dragonflies. Insects galore.
Two other paleontologists, commenting on the find in a separate article in the journal, said that a few other transitional fish had been previously discovered from approximately the same Late Devonian time period, 385 million to 359 million years ago. But Tiktaalik is so clearly an intermediate "link between fishes and land vertebrates," they said, that it "might in time become as much an evolutionary icon as the proto-bird Archaeopteryx," which bridged the gap between reptiles, probably dinosaurs, and today's birds.
350 million years ago, the plants had finally colonized much of the swampy, wetlands. These were extensive due to the tremendous amount of mud due to no organic matter holding down much of the dirt at higher elevations so the rivers and lakes were choked with mud and therefore, probably pretty shallow for extended areas. In these shallows grew dense forests of fern-type plantlife and this stabilized the shorelines and as the plants spread, so did the insects who were the first to crawl out of the waters, dwelling at the edge of the seas. The insects took to these nacsent swampy forests with joy. To this day, if you want to see lots of bugs, go into a swamp!
The insects rapidly evolved and soon, centipedes of gigantic girth and dragonflies the size of small dragons dominated the land. The plants on land and the teeming sealife had created a high oxygen environment. As any farmer knows, insects can be very prolific and multiply like crazy and one suspects the swamps were thick with bugs, zillions of them.
The creature that humans discovered this year probably skuttled around in the thick, murky waters that were too rancid for fish but these guys could breath the oxygen in the air, instead and rapidly evolved into depending on it rather than using gills, and since their eyes were on top and probably quite stereoptic, they looked upwards for their prey. And the insects, unsuspecting, thought this creature was a rotting fern trunk and would thoughlessly land on it to groom or rest and bang, was eaten.
Our earliest mammalian ancestors were insect eaters, too. Indeed, many progenitors of many lines of animals started as insect eaters. This is because insects are plentiful and difficult at the same time and so evolution works rapidly on any creature forced to forage insects for dinner. Unlike eating fruits and nuts or ferns, insect hunters must have good vision, swift reflexes and tongues or hands that can grab and grasp. The ability to climb and jump are usually very quickly developed. Insects have amazing eyes and tremendous flying/crawling skills. I have trained roaches to do my bidding, for example, when I was a super in a slum in NYC years ago. I would surprize the colony suddenly, with a hammer, and crush a few while saying, "Go home."
After a few months of watching their comrades perish in this miserable, loud fashion, all I had to do, to clear a room, was say in a firm voice, "Go home" and they would skitter next door. This kept them out of my apartment sector, for example. It was better than poisons which they evade rather quickly.
Anyway, I suspect our brains are hardwired to outwit bugs. This is why we invented fly swatters. Our distant ancestor didn't need that, he wanted to eat the buggers and did so, happily. Let's just say, we evolved from someone who liked to pretend to be a rotted piece of vegetation just so he could catch roaches.