Stories tagged evolution

Oct
05
2007

Tooling around: A study being conducted in New Caledonia has video footage of crows using twigs and grass to make tools to gather and process their food. (Photo courtesy of the U.S. Fish and Wildlife Service)
Tooling around: A study being conducted in New Caledonia has video footage of crows using twigs and grass to make tools to gather and process their food. (Photo courtesy of the U.S. Fish and Wildlife Service)
I’ve seen films that show chimpanzees using sticks and stones as tools to get and process their food. The narrators always say they’re the only animals to use tools.

Now comes research from New Caledonia, with video to boot, that shows crows make and use tools in their everyday life.

Researchers have mounted tiny video cameras on the tails of crows in that area to record their activities. The footage has even shown the crows manipulating twigs or grass stems to use as tools for gathering their food.

Earlier research showed that crows did use twigs or sticks to dig around for bugs or grubs in dead tree trunks. But new evidence from the video cameras shows that the birds also use grass-made tools on the ground to dig around in bird and animal nests on the ground.

In lab settings, crows have been observed bending wires into tools that they can use to get food. With the new footage, scientists now know that the birds actually use those behaviors in the wild.

The lightweight cameras, just 13 grams, are attached to the tail feathers of the birds. And they actually do modifications to the twigs they select to be their tools. The crows will break off portions of the twig, smooth the surface for bend it into a hook shape to suit their work purpose. And tools that they really liked were kept for future use.

The next big question for these crow scientists to answer: what were the evolutionary factors that have allowed crows to develop this talent and not other birds? Do you have any ideas? Share them here with other Science Buzz readers.

Sep
28
2007

Old air: We're used to seeing oxygen in tanks like this, but some 2.5 billion years ago it was locked up in the Earth's rocks. New studies show that the element is 50 to 100 million years older than previously thought. (Flickr photo by jzawodn)
Old air: We're used to seeing oxygen in tanks like this, but some 2.5 billion years ago it was locked up in the Earth's rocks. New studies show that the element is 50 to 100 million years older than previously thought. (Flickr photo by jzawodn)
Did you know that we can trace the origins of an important element in our air in today’s rocks?

The current issue of the journal Science is reporting that a rock formation recently found in Australia is turning back the origination date of oxygen on Earth.

The new data shows that oxygen was on the planet about 50 to 100 million years before previously thought. It’s not a huge time difference when you consider the previous early indications of oxygen date back 2.3 billion to 2.4 billion years ago.

That’s the time range that researchers like to call the "Great Oxidation Event," and believe me, you wouldn’t have wanted to be around then. Earth’s air was composed primarily of methane and ammonia at that time. The origins of the "Great Oxidation Event" aren’t understood yet, but that was the start of the process that has led to 21percent of our atmosphere being made up of oxygen. And of course, without oxygen living beings like us wouldn’t be able to breath.

The rock core found in Australia is a 3,000-foot-long chunk found in western Australia. The new discovery fuels further speculation that there are strong links between changes in the Earth’s geology and its biology, researchers say. That’s the big question that researchers have to delve into next.

Jul
24
2007

Squish it down, roll it out, and it becomes a worm: Photo NOAA.
Squish it down, roll it out, and it becomes a worm: Photo NOAA.

When it’s related to jellyfish. In 1851 scientists discovered an odd marine worm called Buddenbrockia. Unlike other worms, it has no internal organs. According to Oxford zoologist Peter Holland, “It has no mouth, no gut, no brain and no nerve cord. It doesn’t have a left or right side or a top or bottom – we can’t even tell which end is the front!”

No one knew where exactly if fit on the evolutionary tree. Until now. Holland studied the creatures DNA and found it is actually a close relative of jellyfish, sea anemones and coral.

Before you shrug your shoulders and say “so what?,” realize that Buddenbrockia is a parasite, and comes from a whole family of parasites. It devastates salmon fisheries, and has been hard to eradicate, since the fish farmers didn’t know what they were up against. Now we do.

Holland also notes that this research was made possible by the Human Genome Project, which decoded all the DNA in the human body. Not that human genes have anything much to do with jellyfish and worms. Rather, the Human Genome Project developed new, powerful ways to quickly study DNA. Those methods are now available to other researchers who could never have developed them on their own. In science, we call this the Trickle Down Effect.

Jul
12
2007

A man toys with evolution: For God's sake, sir, stop before you wear yourself out!
Courtesy CB Photography
A man toys with evolution: For God's sake, sir, stop before you wear yourself out!
Courtesy CB Photography
Sometimes, at least.

A recent study, outlined in this article, has reached the audacious conclusion that people walk the way they do because it’s efficient.

Well.

The “inverted pendulum” motion of the body (the way we walk) is the most metabolically efficient way for us to move at low speeds, and the parabolic arch motion (the way we run) is most the most efficient for higher speeds.

The same article points out that this is why “silly walks” are, in fact, so silly: because they are inefficient.

So it turns out that evolution is practical, but not particularly funny.

I have found, however, that almost all walks are funny, if you can just watch them from an upside-down perspective. This can be tricky, but if you find yourself at the science museum any time soon, I recommend you check out the “eyepod” (our camera obscura) in the Big Back Yard. It projects an image of the prairie maze, upside down, on the wall of the room. When you see people moving through the maze from that unusual perspective, they do look pretty silly.

Jul
08
2007

The Platypus: It's watching you. Waiting for you to slip up.
The Platypus: It's watching you. Waiting for you to slip up.
The platypus, also known as “Wait… what?,” bears the distinction of being one of the very few poisonous mammals. The list also includes several types of shrew, the solendon, the slow loris (the elbows of which secrete a toxin which smells like sweaty socks - seriously), and, of course, Coldplay frontman Chris Martin, who put M & M in the hospital for two weeks after delivering a bite just above the left knee.

Both male and female platypoda (check it out, it works) possess a large claw, or spur, on their hind legs. However, only the spurs of the males are venomous. The poison is only produced during mating season, and it is used to defend against predators, and to compete with other males for mates. A strike from a poisonous spur is not enough to kill an animal the size of a human, but victims often suffer incapacitating pain that can last for days or even months. And there is currently no antivenin available for platypus poison.

By studying the evolution of platypus venom, scientists think they can come closer to creating an effective treatment for it. Sequencing of the platypus venom genes shows that the poison evolved from by the “duplication from genes that were once involved in the immune system.” The venom, they have found, contains “defensin”-like proteins. “Defensin” proteins exist in the immune system of the platypus, and are produced as an antibiotic in the milk of some other marsupials.

The hope is that, by knowing the exact toxins involved, scientists can then find which proteins are associated with pain sensation in the victim. Drugs might then be found that could interfere with the venom’s interaction with these proteins.

Not content with simply developing a defense against the platypoda, scientists are also considering how to best develop an active offense against the poisoners – a sort of marsupial preemptive strike. Various methods, ranging from space based high-energy lasers to country-wide “roast” like events (designed to humiliate the platypoda), have been considered. Scientists warn, however, that the implementation of such ideas is still several years off, at least.

The Claw of the Platypus!

The coelacanth (SEE-la-kanth) is a deep-sea fish that has survived unchanged for over 65 million years. It’s limb-like fins suggest it is closely related to the first land animals.

May
29
2007

Creating controversy?: This week's opening of a new museum near Cincinnati has generated new discussions on the origins of the world. Visitors at the museum are first greeted by this giant sauropod dinosaur. (Photo from Creation Museum)
Creating controversy?: This week's opening of a new museum near Cincinnati has generated new discussions on the origins of the world. Visitors at the museum are first greeted by this giant sauropod dinosaur. (Photo from Creation Museum)
The Memorial Day weekend is pretty predictable in the news cycle. Lots of attention, and rightfully so, is provided about the military men and women who’ve given their lives for our country. Then there are the usual stories about the start of summer. And don’t forget the travel delays and stories on high gas prices.

But coming from out of right field this year was Monday’s opening of the new Creation Museum near Cincinnati, Ohio. The $27-million facility had 4,000 visitors on its opening day. Its state-of-the-art animatronics were designed by a former Universal Studios exhibit director. It shows dinosaurs co-existing with Adam and Eve in the Garden of Eden and also riding aboard Noah’s Ark.

With this museum opening, I’ve been amused reading letters to the editor on both sides of the world debate in the local newspapers, particularly in the deep passion expressed by all writers.

My question: is there room at the table for having a museum dedicated to presenting the creationism viewpoint?

Regardless of my personal opinion on the origins of life, I have to give credit to the creationists for putting their money where their mouth is in finding a popular way to express their view. And we all have the option on spending our money and time visiting such a place.

Professionally, I work at the Science Museum of Minnesota which hosts this website. It’s only fair that I let you know where I’m coming from on this. Here’s a link to this museum’s official position on the origins of life.

As a person of faith who does believe our Earth’s origins came several billion years ago, it amazes me that most people find this issue as a non-compromiser. Creationists have an absolute trust in the science they interpret from the Bible, even though through history, Biblical interpretations on things like the shape of the Earth (flat) and it’s position in our solar system (the center) have been proven wrong. Conversely, science does an excellent job of explaining how things work, like the biology of human bodies. But it does a miserable job of explaining how and why we interact with each other: our emotions and feelings.

So let’s have a discussion here on if it’s possible to have intersections between the trajectories of faith and science. Be forewarned, moderators of this blog will not permit long diatribes on one particular point of view. Stick to the topic and your viewpoint will be heard. Let’s explore where there might be common ground between science and faith.

Apr
13
2007

Two years ago, everyone was talking about the work of paleontologist Mary Schweitzer: she noticed that thin slices of a 68-million-year-old fossil femur from a Tyrannosaurus rex looked like they still contained soft tissue. (See photos of the bone.) Using antibodies to the collagen protein, she showed that the bone still contained intact collagen molecules—the main component of cartilage, ligaments, and tendons.

Hello, dinos?: A new study shows that preserved collagen from a 68-million-year-old Tyrannosaurus rex is similar to that of chickens. (Photo courtesy Danelle Sheree)
Hello, dinos?: A new study shows that preserved collagen from a 68-million-year-old Tyrannosaurus rex is similar to that of chickens. (Photo courtesy Danelle Sheree)

She used antibodies to a type of collagen extracted from chickens. The fact that the antibodies stuck suggested that T. rex collagen is similar to that of birds. And when she compared the preserved soft tissue to that of modern animals, the closest match was an emu—a flightless bird.

To learn more about the collagen in the T. rex bones, Schweitzer worked with John Asara, a chemist at Harvard University, to analyze it using mass spectrometry.

The Economist describes the technique this way:

This technique identifies molecules (or fragments of molecules) from a combination of their weight and their electric charges. Knowing the weights of different sorts of atoms (and of groups of atoms that show up regularly in larger molecules, such as the 20 different amino acids from which proteins are assembled) it is usually possible to piece together fragments to form the profile of an entire protein.

When Asara compared the profile he'd created to proteins from living animals, the closest matches were to chickens and ostriches. (Schweitzer and Asara's study was published in the April 13, 2007, issue of the journal Science.)

Many paleontologists already believed, based on fossil bones, that birds are dinosaurs or their descendants. But this new paper provides even more evidence of the fact.

Buzz stories on the subject from last year:

Recent news articles:

Apr
10
2007

Scientists have uncovered the remains of an early modern human in China. The 40,000-year-old skeleton is important, because there are very few human fossils of that age in this part of the world.

Most scientists believe that modern humans evolved in Africa and spread across the globe about 70,000 years ago. They replaced older forms of humans, such as Neanderthals.

Scientists disagree over whether modern humans interbred with the earlier populations. The new fossil, while clearly of a modern human, does contain some features of other types, thus lending weight to the theory that the various populations did mix.

Researchers in Switzerland have built a robot salamander to study how the first amphibians may have moved when they first crawled out of the water to colonize land.