Sunday, June 29, 2008 . 6/29/2008
Unlike intelligent design/creationism, science actually progresses:Bird Family Tree Gets Re-Write
"With this study, we learned two major things," said Sushma Reddy, lead author and a fellow at The Field Museum in Chicago, Ill.
"First, appearances can be deceiving. Birds that look or act similar are not necessarily related. Second, much of bird classification and conventional wisdom on the evolutionary relationships of birds is wrong."
The results of the largest ever study of bird genetics are so widespread that the names of dozens of birds will now have to be changed, says the study to be published in Science magazine.
The Early Bird Assembling the Tree-of-Life Research Project has been researching the evolution of all major living groups of birds and has already examined 32 kilobases of DNA data in 19 places of some 169 bird species.
A kilobase in molecular biology is a unit of length for DNA fragments representing 1,000 base pairs of DNA.
Among new discoveries the team found that birds repeatedly adapted to new environments. For example, flamingos and grebes did not evolve from other water birds, while birds that now live on land such as cuckoos did not evolve from other land birds.
Other findings were that, contrary to current thought, daytime hummingbirds evolved from nocturnal nightjars, falcons are not related to hawks and eagles and fast flying ocean birds are not related to pelicans and other water birds.
"We now have a robust evolutionary tree from which to study the evolution of birds and all their interesting features that have fascinated so many scientists and amateurs for centuries," Reddy said.
"Birds exhibit substantial diversity, and using this 'family tree' we can begin to understand how this diversity originated as well as how different bird groups are interrelated."
Pretty cool, huh? 0 Comments - Post/view comments
Wednesday, May 28, 2008 . 5/28/2008
With a name like T. rex, you'd expect to be safe from even the fiercest paleo-bullies. Turns out, ancient, flying reptiles could have snacked on Tyrannosaurus Rex babies and other landlubbing runts of the dinosaur world.
A new study reveals a group of flying reptiles that lived during the Age of Dinosaurs some 230 million to 65 million years ago did not catch prey in flight, but rather stalked them on land.
Until now, paleontologists pictured the so-called "winged lizards" or pterosaurs as skim-feeders. In this vision, the creatures would have flown over lakes and oceans grabbing fish from the water's surface, much as gulls do today.
The new findings, detailed this week online in the journal PLoS ONE, don't ground the animals totally.
"In our hypothesis, flight is primarily a locomotive method," said co-researcher Mark Witton of the University of Portsmouth in England. "They're just using it to get from point A to point B. We think the majority of their lives, when they're feeding and reproducing, that's all being done on the ground rather than in the air."
To uncover these feeding habits, Witton and Portsmouth colleague Darren Naish analyzed fossils of a group of toothless pterosaurs called azhdarchids, which are much larger on average than other pterosaurs. For example, one of the largest azhdarchids, Quetzalcoatlus, weighed about 550 pounds (250 kilograms) with a wingspan of more than 30 feet (10 meters) and a height comparable to a giraffe.
Witton and Naish learned that more than 50 percent of the azhdarchid fossils had been found inland. Other skeletal features, including long hind limbs and a stiff neck, also didn't fit with a mud-prober or skim-feeder.
"All the details of their anatomy, and the environment their fossils are found in, show that they made their living by walking around, reaching down to grab and pick up animals and other prey," Naish said.
A skim-feeder, such as a gull, trawls its lower jaw through the water, eventually smacking into a fish or shrimp and pulling it from the water. "Regardless of what they hit, the impact force drives the head and neck underneath the body and into the water, thus requiring a hugely flexible neck," Witton said.
This is the case with gulls and pelicans (which are considered plunge divers), but azhdarchid's neck, despite potentially reaching nearly 10 feet (3 meters) in length, was super stiff. "Whatever these animals were doing, it had to involve minimal neck action," Witton said.
Their tiny feet also ruled out wading in the water or probing the soft mud for food. "Some of these animals are absolutely enormous," Witton told LiveScience. "If you go wading out into this soft mud, and you weigh a quarter of a ton, and you've got these dinky little feet, you're going to just sink in."
The reptile's head also was pretty lengthy, up to 10 feet (3 meters). So Witton said an azhdarchid would only have to dip its head part way to the ground, enough for the tip of its jaws to touch down, to hunt and feed on terrestrial prey. Back before they went extinct 65 million years ago during the event that also killed off non-avian dinosaurs, these pterosaurs could lunch on animals ranging from small bird-like Velicoraptors to T. rex babies to amphibians. [Source:LiveScience]
0 Comments - Post/view comments
Thursday, April 10, 2008 . 4/10/2008
Earth's first animal was the ocean-drifting comb jelly, not the simple sponge, according to a new find that has shocked scientists who didn't imagine the earliest critter could be so complex.
The mystery of the first animal denizen of the planet can only be inferred from fossils and by studying related animals today. To get to the bottom of that, scientists analyzed massive volumes of genetic data to define the earliest splits at the base of the animal tree of life.
The tree of life is a hierarchy of evolutionary relationships among species that shows which groups split off on their own evolutionary path first.
The new study surprisingly found that the comb jelly was the first animal to diverge from the base of the tree, not the less complex sponge, which had previously been given the honor.
"This was a complete shocker," said study team member Casey Dunn of Brown University in Rhode Island. "So shocking that we initially thought something had gone very wrong."
Dunn's team checked and re-checked their results and came up with the same result every time: the comb jelly came first. The results are detailed in the April 10 issue of the journal Nature, a journal that, like most respected journals, requires other scientists review a paper prior to publication.
Unlike sponges, comb jellies have connective tissues and a nervous system, and so are more complex. Though squishy and tentacled, they are not, however, true jellyfish as they lack the classic bell-shaped body and characteristic stinging cells.
The finding was unexpected because evolutionary biologists had thought that less complex animals split off and evolved separately first. Dunn says that two evolutionary scenarios can explain why the comb jellies would actually have been first among animals. The first is that the comb jelly evolved its complexity independent of other animals after branching off to forge its own path.
The second is that the sponge evolved its simpler form from the more complex form. This second possibility underscores the fact that "evolution is not necessarily just a march towards increased complexity," Dunn said.
Though scientists can say which animal branched off first, they can't date precisely when this early comb jelly diverged away. "Unfortunately, we don't have fossils of the oldest comb jelly," Dunn said. "Therefore, there is no way to date the earliest jelly and determine when it diverged."
Though comb jellies are a common creature in the seas today, these modern specimens likely look very different from their early ancestors.
Dunn and his team hope that their approach will fill other gaps in the tree of life, including where the branches of many of today's species belong.
Other researchers involved in the study, funded by the National Science Foundation: Gonzalo Giribet of Harvard University, Mark Martindale of the University of Hawaii and Ward Wheeler of the American Museum of Natural History.
[Source: LiveScience]
Aaaaannd cue the dumbass creationists getting all over this. 0 Comments - Post/view comments
Tuesday, February 19, 2008 . 2/19/2008
I don't usually report personal stuff about me but.. this is pretty big. I have this sort of "second ankle" on both my feet, like a bony bump just below my ankles. When I went to get a physical the nurse said it could be an enlargement of a bone there but she didn't know for sure. So since my parents work at a hospital I'm going to be going with them to work next Tuesday to get it checked out, and if possible I'd like to have them removed. The thought of surgery though is scary.. I'd have to use crutches or be in a wheelchair and be crippled for a couple weeks or months or something.Yeah I'm a freak.
--------
With an armored head and a mammoth 16-inch body, it wasn't quite the frog prince. Scientists have discovered the remains of what might have been the largest and fattest frog ever to have lived on Earth.
A team of researchers unearthed the fossilized frog in Madagascar. Dating from about 65 million to 70 million years ago during the Cretaceous Period, the frog is 3.5 inches longer than the largest living frog, the goliath frog of West Africa.
The scientists named the creature Beelzebufo ampinga, or "devil frog," because its incredible size, frightening appearance and predatory nature made them call it "the frog from hell," said Stony Brook University paleontologist David Krause, who led the team that discovered it.
Fierce predators
"They are just these big round blobs, basically all mouth and stomach," Krause told LiveScience. "They were sit-and-wait, ambush predators."
They didn't have very long legs, so they probably didn't hop around much. It was more likely they would let prey come to them. The scientists think they feasted on smaller frogs, lizards and mice.
"When you consider its size, I don't think it's outside the realm of possibility that it could have consumed some hatchling dinosaurs," Krause said. The largest living frog on Madagascar today, at just over 4 inches long, "would have been a nice hors d'oeuvre for Beelzebufo."
The discovery will be reported on-line this week in the journal Proceedings of the National Academy of Sciences (PNAS).
Read more..
I love biology. From the giant crocodiles of the past to Tiktaalik, it never fails to be interesting to me.
Labels: Biology, Evolution, News, Personal
0 Comments - Post/view comments
when will this world wake up and stop believing bold faced lies that come out of a scientists butt who thinks they know everything? if you want to know what killed the dinosaurs, do your research from the only source that matters: the bible.
yea ok, i know that struck a bad chord with many of you out there and probably made quite a number of you expell a mocking scoff, but how many lies does the "scientific community" need to spew out before you start realizing they're just making this baloney up?
Giant birds didn't kill the dinosaurs, the great flood back in noah's time did. after the flood happened, the o2 content in the air was drastically reduced from all of the moisture that was removed from the atmosphere. as a result of that event, the breathing airways in the dinosaurs nasal cavity, trachea, and lungs were too thin to suck in that low amount of oxygen (as would be the case if a human today went from sea level up to 30,000 feet and was suddenly expected to be able to breathe easily), and therefore, they all suffocated shorly after.
i look forward to the day when science is based on the facts and scientific PROOF rather than hocus pocus wizardry that conjures up giant dodo birds that eat dinosaurs.
one more note, if you're at all scientifically inclined, watch the movie Expelled. that is all.
You're speechless after reading that, aren't you? Well, so am I. Almost.
No where in the bible does it mention dinosaurs being killed during this non-existent flood (who's making up shit now?). No where in that article did I see anything about those giant reptiles killing off all the dinosaurs. And where did he get the idea that scientists made this creature up? Even further, what the bloody hell is a creationist doing on a website like LiveScience, a place including, oh I dunno, evidence and reality?
Now if you'll excuse me, I'm going to go decide whether I want to laugh or cry.