The Evolution of Penguins
Science reporters are dancing with happy feet about a news story supposedly explaining how penguins evolved.
The new documentary Flight: The Genius of Birds states, “More than 9,000 species of birds have been identified in the world, and nearly all of them can fly.” The “nearly all” reserves room for flightless birds, such as ostriches, kiwis and penguins. The flightless cormorant on the Galapagos, with its pathetically stunted wings, appears to have descended from mainland birds capable of flight, later becoming adapted to flightlessness on the islands where swimming was sufficient for survival. This is a similar kind of “evolution” to that of blind cave fish, descended from normal fish, losing their eyes as they became adapted to total darkness. In addition, some fossils alleged to be “feathered dinosaurs” are thought by some paleontologists to have been secondarily flightless birds (4/27/12). But what about penguins?
Penguins are superb swimmers, well adapted to their Antarctic climate. They use their wings to “fly” in a different fluid—water, not air. The sight of a swarm of penguins darting through the water under the ice with speed and grace makes for dramatic film footage. Most of the major science news sites (e.g., BBC News, National Geographic, Science Now, Nature News, New Scientist) are claiming that the “puzzle” of penguin flightlessness has been “solved” in a new study published in PNAS. Earlier theories suggested that the lack of predators led to flightlessness, or that evolution had a hard time producing a wing that was good at both flying and swimming.
An international team took a different approach. They measured the energy demands of flight. There’s no question that maintaining flight in the air is costly. Some birds, like cormorants and penguins, are good at both. But if aerial flight is not required for successful feeding, a bird could focus its wings, feet, and other body parts on just the swimming.
The authors measured the energy cost of flying for the guillemot, a bird that looks remarkably like a penguin but can fly (see photo on PhysOrg‘s article; see also 7/23/12 entry). They found that its wings allow it to barely stay aloft; it is exhausting for the bird, that swims effectively to catch fish. They feel the guillemot is near a “tipping point” where it might some day reach an “evolutionary trade-off” to give up aerial flying. They also compared the energy expenditures for murres (10/27/11) and cormorants (5/24/04), two other kinds of fishing seabirds. One co-author put it, “Basically the hypothesis is that as the wings became more and more efficient for them to dive, they became less and less efficient for them to fly.” The abstract says,
These results strongly support the hypothesis that function constrains form in diving birds, and that optimizing wing shape and form for wing-propelled diving leads to such high flight costs that flying ceases to be an option in larger wing-propelled diving seabirds, including penguins.
But how is the change explained in evolutionary theory? Surprisingly, none of the articles mentioned natural selection, even though National Geographic‘s headline quipped, “Why Did Penguins Stop Flying? The Answer Is Evolutionary.” There was no mention of a mechanism for evolving a penguin out of a flying seabird. Presumably, the loss of aerial flight occurred by some kind of negative selection, or “de-evolution.” This doesn’t explain, though, why some seabirds maintained both swimming and flight. Guillemots do not seem to be evolving into something else. In the 7/23/12 entry, researchers found that the birds maintain their energy fitness into old age, even though flight is costly. Certainly, none of the flightless birds thought about exercising an “option” to go swimming only. Somehow, the adaptation had to make it into the genes, otherwise it sounds like Lamarckism (use and disuse, inheritance of acquired characteristics).
None of the articles, in addition, exhibited a chain of fossil birds leading to the penguin. On the contrary, National Geographic offered only speculation:
Scientists don’t have fossils of flighted penguin ancestors, and the earliest known penguin dates to just after the Cretaceous-Tertiary boundary (58 to 60 million years ago).
“It is tempting to speculate that the evolution of penguins happened in that explosive radiation [of mammal species] that happened just after the K-T event,” when many species went extinct, Speakman said. “However, there is no direct evidence to support this, and it could have happened any time during the late Cretaceous.“
So the first fossil penguin was already a penguin. The phrase “explosive radiation,” further, offers no mechanism for evolution to produce complex creatures like elephants and giraffes with new organs requiring large increases in genetic information. Penguins, by contrast, contain all the same basic features as other birds. With their modified wings, they continue to fly—underwater.
Speaking of fossil birds, PhysOrgreported that the classification of Archaeopteryx has been disputed again. One disputant offered this advice: “methodological choices should be based on the adequacy of the assumptions for particular kinds of data rather than on the recovery of preferred or generally accepted topologies, and that certain probability methods should be interpreted with caution as they can grossly overestimate character support.”
National Geographic, we know it’s tempting to speculate. You must learn to resist temptation. Speculation is the besetting sin of Darwinists. Readers, did you catch the reference in that quote to Darwin’s Stuff Happens Law? “It is tempting to speculate that the evolution of penguins happened in that explosive radiation… that happened….” Review the 9/15/2008 commentary.
It’s reasonable to assume that many creationists, even strict recent-creation advocates, would allow for penguins to have ancestors that flew like the guillemot. The similarities are very striking. If creationists can believe blind cave fish “evolved” from seeing fish in a short time, it’s not a stretch for them to suppose that penguin ancestors flew in the Antarctic originally, then lost their wings as life under the sea ice proved sufficient for their needs. This is not Darwinian evolution, because it does not require increases in information, but only modifications to existing genes and gene regulation.
There are reasons, though, to believe that penguins have always been penguins. One is the fossil record. Where is the ancestral evidence for flying penguins? Perhaps one will turn up some day, but in the meantime, we should accept the evidence at face value, that penguins have always been flightless in air. The Creator outfitted each kind of bird with the traits it needed to fill the Earth with a profusion of amazing creatures reproducing after their kind. As usual, the fossil record shows a profusion of larger and stronger representatives in the past (read about “super-penguin” in our 10/01/10 entry). Our world is impoverished after the Deluge.
To appreciate in more detail the mechanisms inside birds that make them such watchable flying machines, be sure to get the new Illustra Media documentary, Flight: The Genius of Birds. You can watch the episode about development in the egg from the film right now on Illustra’s Facebook page. Become a subscriber and join the discussion.