HOME |
RSS | 
It
looks like an insignificant spec of dust, but if scientists are right,
it could be the ancestor of us all.
Meet Otavia antiqua, a microscopic, sponge-like African fossil that could be the earliest known animal:
The creature, Otavia antiqua, was found in 760-million-year-old rock in Namibia and was as tiny as it may be important.
"The fossils are small, about the size of a grain of sand, and we have found many hundreds of them," said study leader Anthony Prave, a geologist at the University of St. Andrews in the U.K.
"In fact, when we look at thin sections of the rocks, certain samples would likely yield thousands of specimens. Thus, it is possible that the organisms were very abundant."
From these tiny "sponges" sprang very big things, the authors suggest. As possibly the first muticellular animals, Otavia could well be the forerunner of dinosaurs, humans-basically everything we think of as "animal."
Read more at National Geographic: Link (Photo: Anthony Prave/University of St. Andrews)
Why do we take a parasitic weed, one that is rather difficult to gather, and hang it in the house so people can kiss underneath? That’s a rather weird tradition when you think abut it. Smithsonian tells several old tales of why we do this, but the real story of how mistletoe evolved from sandalwood into what it is now is the more interesting tale.
Before there were forests, wispy plants fell on each other in their struggle to reach the sun, like clumsy teenagers unsure of their growing bodies. Then one plant evolved a simple woody stem. It could grow taller than the other plants, and it stole light from them. It poisoned them with shade. Wars ensued that have lasted hundreds of millions of years. Trees of many kinds arose and struggled with each other to be taller. Any species that does not participate in battle loses out in the darkness of the understory—any species except a few. Those in the clan of the sandalwood evolved a way out of the darkness. They survived by stealing from the trees what they had spent their tall stems fighting for.
Sandalwood discovered deceit. Its roots kissed the roots of trees and slipped inside them to steal. But sandalwood still needed to grow up a little and put out a few green leaves to have enough sugar to thrive. And then came mistletoes. Mistletoe is a common name for several independent lineages descended from sandalwood. Like their ancestors, mistletoe species sink their roots into trees. Unlike those ancestors, they do so in the sky.
The story continues to explain how mistletoe developed its way of reproducing in the treetops. Link
(Image credit: Flickr user Darwin Bell)
Comments Off
Ah,
the sacrifices that lab mice made. All that perfectly seared tiny organic
burger that they have to eat. You know, for science.
Here's how researchers at Harvard University subjected mice to delicious food in order to find out the evolutionary advantage to eating cooked versus raw meat:
"It came out looking like a beautiful little mini hamburger," says Rachel Carmody, a graduate student in evolutionary biology at Harvard who cooked up the mini-burgers in Petri dishes.
This feast for furry critters was all in the name of science, of course. Carmody and her colleagues served up the mini burgers as part of an experiment to determine the differences in energy provided by cooked versus raw foods.
It turns out that cooked meat delivers more energy than the raw version — which may have given ancient humans an evolutionary advantage. But the extra energy from cooked food may now translate into unwanted pounds because nutrition labels don't reflect the fact that we process cooked food more efficiently.
One giant leap for evolution.
Alice Gibb from Northern Arizona University and colleagues discovered 6 unrelated species of fish that have evolved the strange ability to jump:
Researchers discovered that at least six different types of fish are able to launch themselves into the air from a solid surface.
The team said this was an evolutionary snapshot of the transition from living in water to inhabiting land. [...]
It suggests that, rather than a rare adaptation that evolved in a select few species, the ability to leap on land is common among bony fishes. So many more of their ancient aquatic relatives might have invaded the land than had previously been thought.
Want to know how a bunch of brawny apes evolved into brainy humans? It all comes down to a pair of tongs and a flame.
People and animals eat basically the same food; the only difference is that we cook our meals. But does the ability to flame-broil a burger and burn a meal really make us that special? According to Harvard anthropology professor Richard Wrangham, it does.
Armed with mounting evidence, Wrangham believes that fire-kissed foods are what separated man from beast, allowing our ancestors to grow bigger brains and evolve into the intelligent creatures we are today.
THE MISSING LINK
The story starts roughly 2 million years ago in the age of the habiline -the so-called “missing link” between humans and apes. Habilines walked upright, made primitive stone tools, and had brains the size of oranges (roughly half the size of our brains today). Like chimpanzees, they subsisted mainly on fruits and veggies, with the occasional bit of raw meat on the side. They had strong teeth to chew all that plant matter, and big guts to process all that fibrous material. For them, digestion took an extremely long time. In fact, it’s believed that their bodies were constantly engaged in processing food. (Even today, chimpanzees spend more than six hours a day just chewing.)
So, how did Homo habilis evolve into Homo erectus? The dominant theory since the 1950s has been that meat-eating was responsible for the shift because it required habilines to gradually develop human intelligence. There’s something to the idea: To hunt game, our apelike ancestors had to reply on more than just physical prowess; they had to be clever and cooperate. The better they got at hunting, the smarter they became.
But the “meat made humans” hypothesis rankled biologist Richard Wrangham. In his 2009 book Catching Fire, Wrangham argues that meat-eating alone cannot account for the tremendous physical changes that occurred in the evolution of humans. Instead, he believes that man’s discovery of fire -and more importantly, cooking- did the heavy lifting.
(Image credit: Banksy work, photo by Flickr user Lord Jim)
For decades, many scientists dismissed cooking as a pleasant byproduct of civilization, a symbol of man’s dominion over nature. But Wrangham builds the case that cooking was crucial to human evolution because it made digestion so much more efficient, increasing the amount of energy our bodies derived from what we ate. As a result, humans became better able to think, hunt, sing, dance, paint on walls, and invent new tools. Ultimately, the top chefs were more likely to survive, reproduce, and pass along cooking techniques to their offspring, along with the physical evolutionary changes that come with them -namely, bigger brains.
The idea that cooked food offers more energy than uncooked food doesn’t immediately make sense. After all, recent studies show that cooking can leach food of its calories and nutrients. To understand the answers, we need to look inside -literally.
more …
We’ve brought you the stories of how some famous logos have *evolved, but what about the future? At Stock Logos, we see how some logos become simpler over time, and that trend is projected into the future. Of course, some of these companies are projected to encounter, um, “circumstances.” Link -via Boing Boing
*Previously: Tech, Car, Hollywood, Food, Beer, and Fast Food.
Did you know that Okapi are closer to ancient giraffes than modern day giraffes?
When its ancestor the palaetragine was roaming the earth 15 million years ago, evolution seemed to favor the tall survivors who could reach trees, until finally down the line we had giraffes. Yet one set of palaetragine ancestors moved into the forest and never had to change much from the original: the okapi.
Learn more about ancient species that are still around in this fascinating Environmental Graffiti article.
Link Image Via Charles Miller [Wikipedia]
Comments Off 
With four teenagers at home, I witness every day the strange thought processes they have. We’ve learned from recent research that the human brain undergoes immense changes during adolescence, which are often not finished until the mid-20s. National Geographic looks beyond that research into why the brain goes through such changes in adolescence, and finds it has to do with our evolutionary past. The risks teenagers take are in some ways very adaptive.
Let’s start with the teen’s love of the thrill. We all like new and exciting things, but we never value them more highly than we do during adolescence. Here we hit a high in what behavioral scientists call sensation seeking: the hunt for the neural buzz, the jolt of the unusual or unexpected.
Seeking sensation isn’t necessarily impulsive. You might plan a sensation-seeking experience—a skydive or a fast drive—quite deliberately, as my son did. Impulsivity generally drops throughout life, starting at about age 10, but this love of the thrill peaks at around age 15. And although sensation seeking can lead to dangerous behaviors, it can also generate positive ones: The urge to meet more people, for instance, can create a wider circle of friends, which generally makes us healthier, happier, safer, and more successful.
The entire article is available now in the October issue of National Geographic magazine. Link
(Image credit: Kitra Cahana)
These frogs aren’t going to give up their legs lightly. Species of frog are rapidly evolving adaptations, such as the small fangs they’ve grown, on the island of Sulawesi, Indonesia, and scientists are amazed by how far they’ve come in such a short period of time. One reason is their lack of competition on the island, another reason being the frogs that live on the island all dwell within their own individual pocket, so as to avoid further rivalry over food. Nine species of frogs on Sulawesi have never been documented by scientist before, and thirteen species have developed the cute little choppers, making them look like something out of a Twilight-Muppets crossover. There’s lots more to read on the subject at PhysOrg.com.
Comments Off 
Humans might be one of the only animals to use tools as weapons, but Crack has a great list of animals born with weapons built right into their bodies -like the Giant Amazonian Centipede’s ninja skills, which allow him to catch and eat whole bats. Read about the rest at the link.
Comments Off 
While plants normally have pretty colors in order to attract bugs and other pollinators, one type of plant has evolved to attract bats using sound. I wonder what’s on its playlist?
The Marcgravia evenia plant relies on bats to pollinate its flowers. But given that their target animals rely on echolocation rather than eyesight, these plants have evolved leaves that are attractive audibly rather than visually. The plant’s leaves are uniquely dish-shaped, with almost hemispherical concave curves. When the bats go out flying, the leaves return an echo that’s louder and broader than other plants, making them easier for the bats to detect — and halving the time it takes to find the foliage.
The rodents of the future will eat poison pellets like candy, according to new research conducted on mice found in a German bakery. The baker called in an exterminator to rid his business of the pests and discovered, to his horror, that the little buggers weren’t even fazed by bromadiolone, which is a very concentrated and deadly version of the common rat poison warfarin. This defensive immunity comes from interbreeding with Algerian mice, which had already developed an immunity to the poison. Looks like these unwelcome visitors are determined to stick around, no matter what we throw at them!
Link Image via Image*After
In the eternal struggle for survival, animals are constantly evolving new strategies to win. This arms race is particularly evident when looking at the fight between opossums and snakes. Possums have built up a tolerance to pit viper venom by eating the potential predators. This has also helped them protect themselves from bites from rattlesnakes and copperheads. Even more interestingly though, the viper is constantly evolving more deadly poison:
Rapid evolution of both the snake’s venom and the opossum’s venom defense suggest that the two creatures are in a chemical arms race, having evolved in response to each other, according to researchers at the American Museum of Natural History in an article published in PLoS One.
Learn more over at Discovery News.
Link Image via normanack [Flickr]
The fact that most aliens from outer space in science fiction movies and TV shows have the same shape as humans can be explained rather simply: that’s the only way an actor can fit into the costume. But it doesn’t help us imagine the probability that any extraterrestrial life would not resemble humans at all. Kyle Munkittrick constructed a theory, adapted from an episode of Star Trek: The Next Generation that reconciles this anomaly by explaining why distant planets have human-shaped intelligent beings, called the Hominid Panspermia Theory.
Intelligent life evolved in the universe – 0nce. The First Intelligent Species became spacefaring but, unlike the adventures depicted in most science fiction, they found an uninhabited universe. Non-intelligent species were too rudimentary or too far away to be detected. Thus, as both a memorial to themselves and to enliven the universe, the First Intelligent Species seeded the necessary DNA for the eventual evolution of intelligent life in the primordial oceans of every planet that could support life. The First Intelligent Species did not only design the DNA to evolve intelligently, but to parallel their own evolution. An application of the idea that “ontogeny recapitulates phylogeny” on the scale of life itself. Our corner of the universe thereby became the home of Vulcans, Romulans, Cardassians, Humans, Betazoids, and other hominid species which are all decedents of the First Intelligent Species. Therefore, in the eyes of the universe, the many hominid species are closely related despite their disparate home planets.
Of course, the theory itself is science fiction, but the mental exercise helps the scientist to enjoy science fiction, no matter how cheesy the alien design. As a bonus, the graphic at the article has twenty aliens you are invited to help identify. Link
I write a lot about animals for Neatorama and that’s because I’m always reading about them. The coolest thing about the vast variety of critters is that there are so many and each has evolved their own strange adaptations to survive in their own niche of the planet. With each animal trying to carve out its own special place in the world, it’s not too surprising that there are some that had to dig a little harder and have ended up adapting in very strange ways. These six creatures might not seem too strange at first, but just wait until you read more about their bizarre adaptations.
I’d like to give a special thanks to The Proceedings of the Ever So Strange and The Book of Animal Ignorance, both of which greatly contributed to the information in this article.
Generally, when you’re being attacked by something that wants to eat you, the last thing you want to do is let them get a taste of your delicious, delicious blood to further entice them. But for critters that aren’t as tasty as us humans, this rule applies less and less. In fact, the Texas horned lizard has blood that tastes so gross that it voluntarily gives predators a taste just to show them that they won’t find any pleasure snacking on the lizard. As if that weren’t strange enough though, the source of the lizard’s blood buffet is even weirder …it launches its fluid sample straight from its eye. Even if the taste of the little critter’s blood wasn’t enough to turn away a potential predator, this horrifying scene certainly is!
Source Image via randomtruth [Flickr]
Being the most deadly animal in Africa, the hippo doesn’t have much to worry about in terms of predators. Sure, an occasional lion, croc or hyena might munch on the babies, but once these river monsters grow up, they’re pretty much at the top of the food chain. That’s why their biggest defenses aren’t against other creatures, but against the ravaging African sun and disease-causing bacteria. While rolling around in the mud can work as a natural sunscreen, it’s simply not enough when the majority of their day is spent wading through the river. Instead, hippos have developed their own natural sunscreen, which oozes out of their pores in a shocking, bright red color. This strange secretion has earned the appropriately horrific nickname of “blood sweat,” although it contains neither bodily fluid. Instead, it is made up of a number of highly acidic compounds that absorb ultraviolet light, preventing sunburn, and that inhibit the growth of bacteria. While we usually think of the blood sweat as bright red, it actually comes out clear, turns red and then fades to brown as it becomes exposed to the air.
Being stuck on an island with no natural predators, the Komodo dragon already has a good evolutionary hand, growing to become the largest living lizards on earth, reaching almost 10 feet long. But as many lizards will be happy to tell you, “size doesn’t matter,” so the Komodos also evolved a quite nasty way to bring down their prey.
more …
The Miss USA Beauty Pageant was held this past weekend (celebrating 60 years no less) and the big question everyone wanted to know wasn’t what these young ladies were going to wear in the swimsuit competition. We were all sitting on the edge of our seats interested to know their thoughts on the question “Should evolution be taught in school?” See the full video at the link for the fascinating answers.
Recent advances in genetic research have allowed scientists to grow the brain of one animal inside he body of an entirely different species. Is this the dawning of a new era or a scene out of The Island of Dr. Moreau?
The idea of splicing animals together isn’t a new one The ancient Greeks fashioned a chimera out of a snake, a goat, and a lion; the Japanese made a baku out of an ox, an elephant, and a tiger. Even today, people are inventing new creatures -only now, they’re using a lot more than their imaginations.
Just ask biologist Todd Streelman. Inside his lab at Georgia Tech, Streelman successfully bred a living animal with the brain of anther species. He started with a cichlid, a type of fish found in Lake Malawai, at the southern tip of Africa’s Great Rift Valley. Over the past 500,000 years, hundreds of different species of the cichlid have evolved from a single ancestor, with each new species developing a distinct set of jaws, teeth, brain, and behaviors to fit their respective environments. Streelman took two species of cichlid fish -rock-dwelling cichlids and sand-dwelling cichlids- and figured out a way to grow a sand-dweller’s brain inside the skull of a rock-dweller. From a distance, that might seem like a simple trick in cross-pollination. But it’s no small feat when you consider that the brains of the two creatures are as different as those of chimpanzees and humans.
Todd Streelman
ANIMAL CROSSING
How’d he do it? The trick to Streelman’s success was figuring out how (and when) the brains of different species distinguish themselves during embryonic development. In the earliest stages of life, the brain of almost every animal starts out looking the same. It begins as a small sheet of rapidly dividing cells that are not yet designed for different functions. But this sheet of cells eventually rolls into a tube, and the cells turn into different types of neurons. The neurons then slowly forms connections uniquely tailored to the creature’s lifestyle. In humans, for example, the brain develops a large cerebral cortex capable of processing language and consciousness. In various species of cichlid fish, the forebrain changes and grows depending on its future environment. More specifically, the sand-dweller’s forebrain develops a large hind region for surviving in open water, while the rock-dweller’s forebrain develops a large front region to navigate Lake Malawi’s murky, cavernous bottom.
In both species, the size and shape of the forebrain is determined by the expression of a gene called Wnt1. In sand-dwellers, this gene sends out a strong signal, while in rock-dwellers, Wnt1′s signal is weak. As part of his study, Streelmen took rock-dweller embryos and placed them in water treated with lithium chloride -a salt that’s known to increase the strength of the Wnt1 signal. This caused the rear section of the rock-dweller’s brain to grow until its brain looked like that of a sand-dweller. In other words, by simply changing the expression of a single gene, Streelman was able to Frankenstein a new fish.
Cichlid embryo
OF MICE AND MEN
While Streelman has proven that he can grow one species’ brain inside another’s body, there’s no telling if his patchwork creations can survive in their natural environments. To date, most attempts to manipulate neural development in animals have led to brains that look promising in the land but fail to function in the real world. In 2002, for instance, researchers manipulated a mouse’s genetic signals to increase the size of its cerebral cortex. The cortex grew dramatically, forming folds indicative of the intelligence in high-order mammals and humans. But the mutation proved fatal, and the mouse died before it was born.
Some scientists posit that the mouse’s death may have had more to do with the complex relationship between the animal and environment and less to do with ill-suited manipulation. Georg Striedner, and evolutionary biologist at the University of California at Irvine, has found that many animals go through a phase during early development in which they’re particularly vulnerable to injury, starvation, or disease. In order for an animal to survive, something in their external world has to protect them. For instance, many species go through a prolonged period of rapid cell division before their brains become neurons. This ultimately leads to a larger brain, but it also means that the animal’s brain is not fully formed at birth. Parrots are a good example. After parrots hatch, their brains aren’t particularly developed, which forces the babies to rely on their mothers for food. That means that the mothers’ feeding behaviors must have evolved at the exact same time that parrots evolved to have larger brains. Otherwise, parrots would have never become so smart.
Cichlid fish
The process of evolving new traits is clearly complicated. Labs can create animals with shiny new traits, but that doesn’t mean the animals can handle the complexity of the world around them. As for Streelman’s fish, no one knows how their manipulated brains will affect their behavior -or, for that matter, how they’ll fare in nature. In many ways, though, that isn’t the point. The goal of Streelman’s research isn’t to grow new and funky animals; it’s to learn how animals evolve. By discovering the relationship between the animal’s genome and its brain development, scientists ultimately hope to pinpoint the genetic basis of of human thought and behavior. It just may be that, along the way, creatures like the chimera and the baku become more than the stuff of ancient folklore.
_______________________
The article above, written by Adam K. Raymond, is reprinted with permission from the March-April 2011 issue of mental_floss magazine. Get a subscription to mental_floss and never miss an issue!
Be sure to visit mental_floss‘ website and blog for more fun stuff!
Many science fiction scenarios have planets with two or even more stars. How would life evolve differently under such a system?
In a new study, researchers have assessed the potential for photosynthetic life in multi-star systems with different combinations of sunlike stars and red dwarfs to figure out what plants might be like. The team has speculated that on an Earth-like planet with two or three suns, the vegetation may appear black or grey.
“If a planet were found in a system with two or more stars, there would potentially be multiple sources of energy available to drive photosynthesis,” said PhD student Jack O’Malley-James from the University of St. Andrews in Scotland.
“The temperature of a star determines its colour and, hence, the colour of light used for photosynthesis. Depending on the colours of their star-light, plants would evolve very differently.”
If a life form evolved to use two different colors of light for energy, the vegetation would appear black to our eyes. They might even develop the ability to use infrared or ultraviolet light that we can’t see at all to power photosynthesis. Link -via reddit
If Evolution Really Works – $9.95
Are you looking for the perfect Mother’s Day gift for your favorite multitasking Mom? Well, look no further! You need the If Evolution Really Works… T-shirt from the NeatoShop. This T-shirt is all but guaranteed to give your hard working Mom a well deserved laugh.
Be sure to check out the NeatoShop for more Funny T-shirts and Mother’s Day Gift!
Comments Off 
Paleontologist Josep Quintana Cardona of the Mediterranean island of Minorca and colleagues have discovered the fossils of the largest rabbit that ever lived on Earth:
The new hunk of a rabbit, now named Nuralagus rex, shows the kind of unusual turn that evolution can take on islands. “Gigantism happens,” explains Brian Kraatz of Western University of Health Sciences in Pomona, Calif. When pioneer animals start colonizing an island, rates of evolution typically speed up at first, he explains. Small creatures can supersize, and big ones can shrink. [...]
So far no plausible rabbit-eaters have turned up among fossils from the same stretch of time on Minorca, so the big bunnies could have evolved larger and larger body size without pressure to maintain speed and agility to escape predators. The relatively short, stiff spine of the fossils suggests that Nuralagus didn’t hop much, if at all, say Quintana Cardona and colleagues. They describe its pace as “low-gear walking.” [...]
What the rabbit king of Minorca did have were paws adapted for digging, a help in finding food to sustain its regal size. So far, though, there’s no sign of giant carrots.
Slow and steady wins the race, right? Well, at least in Aesop’s fable and now, it seems, also in evolution – at least if you’re a bacterium:
Research carried out in Richard Lenski’s lab at Michigan State University in East Lansing, and published today in Science 1, shows that rapidly evolving ‘hare’ bacteria were eventually wiped out by their more sluggish rivals.
The reason was that the ‘tortoise’ bacteria had a higher ‘evolvability’, or a greater potential to take advantage of future beneficial mutations, than their speedier competitors, despite a tendency to accumulate such mutations at a slower rate. [...]
Cooper and his colleagues looked at two Escherichia coli clone lineages, sampled after 500, 1,000 and 1,500 generations of evolution. They came from a long-term bacterial evolution experiment running in the lab.
By looking for the presence of five beneficial mutations, the researchers found that ‘hare’ bacteria had more advantageous genetic changes than ‘tortoises’ after 500 generations, suggesting they were more likely to go on to successfully survive and reproduce, and to eventually wipe out their competitors altogether.
But looking at the later generations, the team found that ‘tortoises’ had overtaken ‘hares’ and gone on to dominate the population.
Comments Off 
Prejudice is terrible, but is it uniquely human? No, according to a new research on rhesus macaques by Yale psychologist Laurie Santos. Blame evolution:
"One of the more troubling aspects of human nature is that we evaluate people differently depending on whether they’re a member of our ‘ingroup’ or ‘outgroup,’" Santos said. "Pretty much every conflict in human history has involved people making distinctions on the basis of who is a member of their own race, religion, social class, and so on. The question we were interested in is: Where do these types of group distinctions come from?"
The answer, she adds, is that such biases have apparently been shaped by 25 million years of evolution and not just by human culture.
Research into why Transylvanian naked neck chickens have naked necks reveals a complex balance between genes and chemicals that produce a bird’s (not just chickens) feather pattern while it is still an embryo in an egg. Once the combination was discovered, Chunyan Mou from the University of Edinburgh found that bird necks are naturally more disposed to nakedness than the rest of their bodies. This may be no benefit to poultry, but chickens are related to birds that do benefit.
Mou thinks that similar genetic tweaks have happened time and again in the evolution of birds. Many groups have lost their neck feathers independently, including vultures, the marabou stork, and large flightless birds like ostriches and emus. Naked necks allow vultures to stuff their heads into carcasses without soiling any feathers; in other cases, a naked neck probably helps its owner to keep cool in hot climates.
Whatever the benefit, it seems that it’s particularly easy for birds to evolve a naked neck, rather than another part of their body. After all, Mou found that the necks of embryonic ducks, turkeys, quails and guinea fowl all have much higher levels of retinoic acid than the rest of the body. This pattern would normally be innocuous, completely hidden from natural selection. But it allows BMP-boosting mutations to denude the neck in one fell swoop, while keeping the rest of the body covered in feathers. As Mou writes, “An underlying map within the skin provides a one-step route to a bare neck.”
The post goes into detail about how the genes initiate the production of chemical activators and inhibitors, and ends with a parable from Alan Turing that explains the concept in layman’s terms. Link
(Image credit: Demontux)
This chart makes me hungry. From Abstruse Goose. Link -Thanks, Oscar!
Fish in the Hudson River (US) have developed an immunity to polychlorinated biphenyls, a type of toxic chemicals developed in 1929. They’ve done so at an amazing speed:
“This is very, very rapid evolutionary change,” said Isaac Wirgin, an environmental toxicologist at New York University’s School of Medicine, and the study’s lead investigator. “Normally you think of evolution occurring in thousands to millions of years. You’re talking about all this occurring in 20 to 50 generations maybe.”
The fish in question is called the tomcod, and scientists have determined the specific gene which has changed:
It turns out the fish sport a handy modification to a gene encoding a protein known to regulate the toxic effects of PCBs and related chemicals, called the aryl hydrocarbon receptor2, or AHR2.
The fish are missing six base pairs of DNA of the AHR2 gene, and the two amino acids each triplet would code for. PCBs bind poorly to the mutated receptors, apparently blunting the chemicals’ effects.
The adaptation occurs almost universally in Hudson River tomcod, but crops up only infrequently in two other tomcod populations—in Connecticut’s Niantic River and the Shinnecock Bay at Long Island’s south shore.
Link via reddit | Photo: Mark Mattson, Normandeau Associates
Vladimir Nabokov was the curator of butterflies at the Museum of Comparative Zoology at Harvard University. The lifelong butterfly researcher posed a theory of butterfly evolution in 1945. He said butterflies came to the New World in five waves of migration, through Asia across the Bering Strait into Alaska and then southward through North and then South America (much as humans migrated). Other butterfly experts scoffed at the idea. Nabokov’s theory was not taken seriously until after his death in 1977. Then, in the past decade, gene-sequencing technology finds that Nabokov was right all along! A paper co-authored by Naomi Pierce of Harvard was presented to the Proceedings of the Royal Society of London on Tuesday that proclaimed Nabokov’s theory to be supported by genetic research.
There were several plausible hypotheses for how the butterflies might have evolved. They might have evolved in the Amazon, with the rising Andes fragmenting their populations. If that were true, the species would be closely related to one another.
But that is not what Dr. Pierce found. Instead, she and her colleagues found that the New World species shared a common ancestor that lived about 10 million years ago. But many New World species were more closely related to Old World butterflies than to their neighbors. Dr. Pierce and her colleagues concluded that five waves of butterflies came from Asia to the New World — just as Nabokov had speculated.
“By God, he got every one right,” Dr. Pierce said. “I couldn’t get over it — I was blown away.”
Dr. Pierce and her colleagues also investigated Nabokov’s idea that the butterflies had come over the Bering Strait. The land surrounding the strait was relatively warm 10 million years ago, and has been chilling steadily ever since. Dr. Pierce and her colleagues found that the first lineage of Polyommatus blues that made the journey could survive a temperature range that matched the Bering climate of 10 million years ago. The lineages that came later are more cold-hardy, each with a temperature range matching the falling temperatures.
In case you were wondering, yes, this is that Vladimir Nabokov. He is better known outside scientific circles as the proclaimed author of Lolita and other novels. Link -via The Loom
(Image credit: Vlad Dinca)
Got a crotchety old guy who kept telling you that youngsters today are getting dumber by the minute (right before he told you to get off his lawn)?
Well, he may be onto something: scientists discovered that our brains are actually shrinking!
The downsizing of human brains is an evolutionary fact that took science writer Kathleen McAuliffe by surprise.
"I said, ‘What? I thought it was getting bigger!’" she tells NPR’s Jacki Lyden. That was the story up to 20,000 years ago, she learned. Then, the brains of our ancestors reversed course and started getting smaller — and they’ve been shrinking ever since.
Cro-Magnon man, who lived in Europe 20,000 to 30,000 years ago, had the biggest brains of any human species. In comparison, today’s human brain is about 10 percent smaller. It’s a chunk of brain matter "roughly equivalent to a tennis ball in size," McAuliffe says.
The experts aren’t sure about the implications of this evolutionary trend. Some think it might be a dumbing-down process. One cognitive scientist, David Geary, argues that as human society grows increasingly complex, individuals don’t need to be as intelligent in order to survive and reproduce.
I don’t know about the science, but it sure explains Jersey Shore! Link
Photo: Emergency Inflatable Brain from the NeatoShop
Having cured cancer and other serious ailments, a team of Japanese scientists from the University of Osaka turned to the next most vexing scientific problem facing the world today, the lack of singing mice, and licked that problem too. No seriously. Singing mouse.
A team of researchers at the University of Osaka created the animal in their "Evolved Mouse Project", in which they use genetically modified mice that are prone to miscopying DNA and thus to mutations.
"Mutations are the driving force of evolution. We have cross-bred the genetically modified mice for generations to see what would happen," lead researcher Arikuni Uchimura told AFP.
"We checked the newly born mice one by one… One day we found a mouse that was singing like a bird," he said, noting that the "singing mouse" was born by chance but that the trait will be passed on to future generations.
"I was surprised because I had been expecting mice that are different in physical shape," he said by telephone, adding that in fact the project had also produced "a mouse with short limbs and a tail like a dachshund".
Disney, understandably, should be worried:
Uchimura dreams of further "evolution" of mice through genetic engineering.
"I know it’s a long shot and people would say it’s ‘too absurd’… but I’m doing this with hopes of making a Mickey Mouse some day," he said.
Now, if you were to breed a Frankenmouse, would you really make a singing mouse? I mean, what’s the military application of that?
Israeli archaeologists have found teeth of modern humans in a cave in central Israel that date back 400,000 years. That makes them twice as old as modern humans found in Africa, which is where they’ve been thought to have originated.
“It’s very exciting to come to this conclusion,” said archaeologist Avi Gopher, whose team examined the teeth with X-rays and CT scans and dated them according to the layers of earth where they were found.
He stressed that further research is needed to solidify the claim. If it does, he says, “this changes the whole picture of evolution.”
The accepted scientific theory is that Homo sapiens originated in Africa and migrated out of the continent. Gopher said if the remains are definitively linked to modern human’s ancestors, it could mean that modern man in fact originated in what is now Israel.
Sir Paul Mellars, a prehistory expert at Cambridge University, said the study is reputable, and the find is “important” because remains from that critical time period are scarce, but it is premature to say the remains are human.
The archaeologists from Tel Aviv University are confident that other human fossil evidence will be found at the site. Link -Thanks, özi!
(Image credit: AP/Oded Balilty)
Hundred of millions of years ago, sea creatures crawled up on land and started to become mammals. Then much later, a few went back into the sea, but left few fossils to show us how they did it -or at least that’s what we used to think.
For more than a century, our knowledge of the whale fossil record was so sparse that no one could be certain what the ancestors of whales looked like. Now the tide has turned. In the space of just three decades, a flood of new fossils has filled in the gaps in our knowledge to turn the origin of whales into one of the best-documented examples of large-scale evolutionary change in the fossil record. These ancestral creatures were stranger than anyone ever expected. There was no straight-line march of terrestrial mammals leading up to fully aquatic whales, but an evolutionary riot of amphibious cetaceans that walked and swam along rivers, estuaries and the coasts of prehistoric Asia. As strange as modern whales are, their fossil predecessors were even stranger.
These fossils raise almost as many questions as they answer. Read more at Smithsonian magazine. Link
