Evolution

It turns out the core of the Earth is closer to about 6000 degrees Celsius, about 1000 degrees hotter than previously estimated. This is good, because the difference between the core and the mantle needs to be at least 1500 degrees to create a magnetic field. To read more about the new estimate and why the old estimate was wrong, go to:

http://www.sciencedaily.com/releases/2013/04/130425142355.htm

Evolution

Happy DNA Day!

Today marks the 60th anniversary of Francis Crick, James Watson, Rosalind Franklin, and Maurice Wilkins publishing articles regarding the structure of DNA in Nature. There had been an intense race to figure out the structure among the top minds in biology and biochemistry, and the double helix almost seemed too simple to be true. These findings forever changed biology, and helped spark the advancement of genetics, and subsequently, evolution.

In 1962, Watson, Crick, and Wilkins were awarded the Nobel Prize for this discovery. Rosalind Franklin had died by this time, and the prize is not given posthumously.

Pictured: Alan Alda, James Watson, Tracy Day, and Brian Greene at the 60th anniversary gala, put on by the World Science Festival.

More info: http://bbc.in/14TlXpO

Read the original papers: http://bit.ly/17YygNk

Photo credit: Greg Kessler

Science Is Awesome

Today is DNA Day, a holiday commemorating the day in 1953 when James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin and various colleagues all published papers on the structure of DNA.

This discovery revolutionized biology and was without a doubt one of the most important scientific discoveries of the last 100 years.

All of their papers are now freely available for the public to read.Celebrate DNA day by reading the original research articles, and by passing them along for friends to read.

Watson, James Dewey; Crick, Francis Harry Compton (1953-04-25). "Molecular structure of nucleic acids; a structure for deoxyribose nucleic acid". Nature 171 (4356): 737–738. Read here:http://bit.ly/13asBk

Franklin, Rosalind Elsie; Gosling, Raymond (1953-04-25). "Molecular configuration in sodium thymonucleate". Nature 171 (4356): 740–741. Read it here: http://bit.ly/hf4eaz

Wilkins, Maurice Hugh Frederick; Stokes, Alexander Rawson; Wilson, Herbert R. (1953-04-25). "Molecular structure of deoxypentose nucleic acids". Nature 171 (4356): 738–740. Read it here: http://bit.ly/17WK6dI

Evolution

This snake won't be batting its eyelashes at you coquettishly.

This beautiful snake is an eyelash pit viper (Bothriechis schlegelii). Found from southern Mexico to northern South America, this arboreal viper loves a variety of habitats: from tropical lowlands to high elevation cloud forests. They feed on small birds, amphibians, and reptiles.

These vipers rarely move to the ground, prefering to hang in the branches of trees. So watch out if you're moving through the forest and reach for a vine. You don't want to grab one of these!

Photo courtesy of:

http://www.hidephotography.com/getpage.php?pg=search&sr=Dendrobates+auratus

Sources:

http://animaldiversity.ummz.umich.edu/accounts/Bothriechis_schlegelii/

Evolution

Is that Alien?

Nope. Just Phronima sedentaria, an amphipod that lives in the deep ocean. This strange creature is usually less than 1 inch long, so it probably isn't going to terrorize the planet any time soon.

Females of this species will capture and eat the inside of a salp (a tunicate that resembles a jelly fish) and use the bell of the now-empty salp to protect her young. When the young are large enough, they eat the salp and swim away.

Picture courtesy of:

http://news.nationalgeographic.com/news/2007/08/photogalleries/sea-creatures/photo4.html

Sources:

http://www.cabrillomarineaquarium.org/exhibits/socal-species-details.asp?id=36

http://news.nationalgeographic.com/news/2007/08/photogalleries/sea-creatures/photo4.

Evolution

Monkeys and sloths fear this bird. Because it rips them right out of the trees.

The harpy eagle (Harpia harpyja) is one of the largest and most powerful birds of prey. Its wingspan can reach 7ft (a little over 2m) and the female can weigh up to 20lbs (9kg). Females are larger than males, which can reach 12lbs (5.4kg). Its talons are about 5 inches (13cm) long, rivalling a grizzly bear's claws. It can be found in the tropics from southern Mexico to southern Brazil.

Photo courtesy of:

http://www.royle-safaris.co.uk/harpy-eagle-specialist-tour-2637/

Sources:

http://www.sandiegozoo.org/animalbytes/t-harpy_eagle.html

Evolution

About 23 million years ago, when the Tibetan Plateau began to rise, a river was born.

The Yangtze river runs through China, from the Tibetan Plateau to the East China sea. It is the world's third longest river (6300 kilometers or about 4000 miles) and scientists have long debated its age. Now, thanks to researchers from Nanjing Normal University in China, the age of the river was determined using rocks found in the Jianghan Basin (below the Three Gorges Dam).

Picture courtesy of:

http://www.china-tour.cn/China-Pictures/Yangtze_River_Three_Gorges_1.htm

Sources:

http://www.sciencenews.org/view/generic/id/349900/description/News_in_Brief_Yangtzes_age_revealed

Evolution

Kangaroo rats (Dipodomys spp.) take adorable rodents to a whole new level. K-rats, as they are usually called, have powerful hind legs similar to a kangaroo, hence the name. A long, tufted tail, big head, big eyes, and little ears finish off the k-rat's adorable look. There are 23 species of k-rats, most of which live in the arid to semi-arid western and mid-western U.S.A. Several species are unique to California, and five species from California are endangered.

K-rats live in burrows and are strictly nocturnal. They mostly eat seeds, and they are notorious seed hoarders. K-rats will gather as many seeds as they can in their cheek pouches and create large caches of seeds in their burrows.

Living in such arid environments, the k-rat has one of the most amazing osmoregulation systems among mammals. It is able to survive without drinking water, using only water produced through metabolic processes.

Picture courtesy of:

http://www.tumblr.com/tagged/kangaroo%20rat

Sources:

http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2005/Stoudemire/

http://icwdm.org/handbook/rodents/KangarooRats.asp

Evolution

Researchers studying the DNA copying process in Escherichia coli found that the proteins copying DNA stop frequently in the copying process. During these pauses, mistakes can be made in the copy, which can cause mutations that lead to cancer and other dangerous diseases. Normally, cells can repair the damage and the copying proteins responsible.

E. coli is used as a model organism, giving scientists insight into how basic processes may work in humans.

Picture courtesy of:

http://bioweb.uwlax.edu/bio203/s2008/moder_just/

Sources:

http://www.sciencedaily.com/releases/2013/04/130418104334.htm

Evolution

A 95 million year gap in the Madagascan fossil record has been filled! Before this, no fossils from “between 70 and 165 million years ago could be identified.”

Dahalokely tokana (which means ‘lonely small bandit’ in the Malagasy language) was dug up in 2007 and 2010. The specimen was identified all the way down to the species level based on the uncovered vertebrae and ribs. These areas are very distinctive in some dinosaurs and can be used to identify them. The scientists were able to classify Dahalokely as an abelisaurid.

Dahalokely roamed the earth around 90 million years ago, at a time when Madagascar and India were connected, but isolated from other landmasses. As such, it is possible that Dahalokely was the ancestor of subsequent animals that lived in both India and Madagascar. Indeed, the fossils display features that are found in dinosaurs from both India and Madagascar. However, too little is known about this species for the evidence to be conclusive. As such, this is still a matter to be researched. "This just reinforces the importance of exploring new areas around the world where undiscovered dinosaur species are still waiting."

Read all about it: http://bit.ly/14BMuaT
Image: An artist’s depiction of Carnotaurus, another abelisaurid, which lived in what is now South America.
Image source: http://bit.ly/Z8IfPW

Evolution

The coelacanth (Latimeria chalumnae and Latimeria menadoensis) is called a living fossil because it closely resembles its ancestors, which lived 300 million years ago. Long thought extinct, the coelacanth resurfaced in 1938 when it was caught in a net off the coast of Africa. Even now, it's difficult to find a coelacanth because these ancient fish live deep in the ocean, often in caves.

Coelacanths also have four very large, thick fins, which scientists have long thought were a sign that this fish was a stepping stone in the move from water to land.

Researchers sequenced the genome of coelacanths, and compared coelacanths and lungfish (a fish with lungs) to land based animals. As it turns out, lungfish were more closely related to land based animals, suggesting that perhaps lungs were more important than legs in getting animals out of the water.

Photo courtesy of:

http://vertebrates.si.edu/fishes/coelacanth/coelacanth_wider.html

Sources:

http://www.bbc.co.uk/news/science-environment-22184556

http://www.sciencenews.org/view/generic/id/349739/description/News_in_Brief_Coelacanth_is_not_closest_fishy_relative_of_terrestrial_animals

http://vertebrates.si.edu/fishes/coelacanth/coelacanth_wider.html

Moore's Law predicts life originated billions of years before Earth
http://io9.com/moores-law-predicts-life-originated-billions-of-years-476129496

HOW CHRISTIANITY WAS INVENTED: THE TRUTH!

http://beyondallreligion.net/2012/01/21/how-christianity-was-invented/

List of atheists in science and technology

http://en.wikipedia.org/wiki/List_of_atheists_in_science_and_technology

50 Top Atheists in the World Today

http://www.thebestschools.org/blog/2011/12/01/50-top-atheists-in-the-world-today/

Evolution

Researchers uncover the most complete picture yet of how Australopithecus sediba, a possible immediate human ancestor, walked and moved.

The team analysed two skeletons: a juvenile male (known as MH1), a female (MH2) and the isolated shinbone of an adult male (MH4). The two-million-year-old skeletons were found together (along with the fossils of several other animals, such as sabre-toothed cats, birds and mice) in 2008 and it has been speculated that they belong to a mother and son. It's only now, over 4 years later, that researchers have been able to fully analyse them.

The skeletons reveal that while Au. sediba was capable of bipedal walking, it did so in a very different manner than us. Traits such as a small heel (reminiscent of a chimp's) mean that it walked using a strange rotation of the knees and hip, with feet turned inwards. While it could walk bipedally, it would not have been a good runner - its narrow shoulders mean it could not swing its arms as we do (which saves energy). Our broad chest is one of the reasons humans are good long-distance runners, and the evidence suggests Au. sediba could not walk or run as well as we can.

But walking was not Au. sediba's only method of locomotion. Its long arms, shoulder blades and the narrow top of its ribcage are all very similar to those of orangutans and indicate a lifestyle that was at least partly arboreal. Brachiation (when apes swing from tree to tree with their arms) may have been a way for Au. sediba to get around.

The spine and teeth of the specimens demonstrate some human-like characteristics. Au. sediba likely had the same number of vertebrae as us (with a human-like hollow back) but it was more flexible than ours. The teeth bear similarities to Au. africanus, suggesting that these two australopiths were distinct from Au. afarensis (the species the famous "Lucy" skeleton belongs to).

As for whether Au. sediba is an immediate common ancestor to the Homo genus, that debate is a long way from being settled. Not all remains are as complete as these; many members of the Hominid line are known from fragmentary remains which can't be properly compared against Au. sediba, and some argue we have Homo fossils that predate these skeletons. More fossils may be the only way to definitely answer where Au. sediba lies in our family tree.

Photo: In the centre is a reconstructed Au. sediba based on the material of MH1, MH2 and MH4. Shown against the skeletons of a small-bodied modern woman (left) and a chimp (right). Credit to Lee Berger.

General articles:
http://news.nationalgeographic.com/news/2013/13/130411-homo-ancestor-hominin-skeleton-lucy-australopithecus-sediba-science/

http://www.bbc.co.uk/news/science-environment-22108784

http://www.livescience.com/28656-closest-human-ancestor-was-pigeon-toed.html

http://www.sciencedaily.com/releases/2013/04/130411142719.htm

On the ribcage, feet and running: http://www.sciencedaily.com/releases/2013/04/130411142942.htm

On different forms of bipedalism among human ancestors: http://www.sciencedaily.com/releases/2013/04/130411142710.htm

What Au. sediba's teeth tell us: http://www.sciencedaily.com/releases/2013/04/130411142935.htm

Science Is Awesome

An experiment taking place on board the International Space Station is close to explaining one of the great mysteries of our understanding of the universe - dark matter.
The team announced today that the first results from the Alpha Magnetic Spectrometer have shown hints of what is theorized to be dark matter. Dark matter, which is believed to hold the universe together, has never before been directly observed.

More info: http://bit.ly/Z8nUW9

Evolution

The plainfin midshipman may not look like much, but it's not looks that have earned these fish the interest of scientists - it's their impressive voices.

When mating season comes around, large male plainfin midshipman (Porichthys notatus) attract females by humming. They're very good at it too; they can be so loud they've elicited complaints from California houseboat residents that they couldn't sleep or hold conversations over the din. Some claim to have felt their homes vibrating.

This is especially interesting when you consider fish don't have vocal chords. They've evolved another method - the midshipman creates its hum by vibrating muscles against the sides of its swim bladder (a gas-filled organ used for buoyancy). They use the same method to make aggressive grunts towards intruding males. Strangely, males in the same area seem to actively match the pitch of their hum against each other. Males of one "community" tend to sound different to males in another.

But a constant loud, low hum can't be good for your hearing. To avoid damaging their hearing, these fish can actually regulate their hearing and can listen for females and predators over the hum. Both sound and hearing are controlled by the same part of the fish's brain - hearing sensitivity is reduced the moment humming starts. It's hoped learning more about how the midshipman regulates its hearing could teach us more about our own.

Oh, and remember when we said large male midshipman hum? That's because there's actually two types of males, and the smaller males don't bother. Once the humming male attracts the female to his nest in the mud, she lays her eggs for him to fertilize. But sometimes he's beaten to it by a smaller male, who sneaks into his nest and fertilizes the eggs (presumably because they fertilize their eggs in the nests of large males, sneaky males don't have nests). The differences between male types is substantial: humming males can be eight times larger than sneaky males, but sneaky males have testicles about seven times larger than the humming male's.

Photo: Plainfin midshipman hiding in the sand. They spend the day this way as they are nocturnal. Credit to Terrance J. Fidler.

http://www.livescience.com/27237-fish-sings-for-mates.html

http://phys.org/news157224812.html

http://www.nature.com/news/2005/050711/full/news050711-1.html

http://beheco.oxfordjournals.org/content/17/4/670.full.pdf

http://bit.ly/10pK34u

Evolution

Researchers from Canada, Taiwan, the People's Republic of China, Australia, and Germany worked together to excavate a site in Lufeng, China. They found some of the oldest known embryonic dinosaur fossils (from the lower Jurassic), allowing them to examine the development of dinosaur embryos in greater detail than ever before.

Even more exciting, they found what may be collagen fibers in the fossils. Fossils are bones turned to rock over time, and to find organic material in such old fossils is amazing.

To read more about dinosaur babies, go to:

http://www.sciencedaily.com/releases/2013/04/130410131216.htm

Picture courtesy of:

http://www.sciencedaily.com/releases/2013/04/130410131216.htm

Science Is Awesome

How would you feel about walking around covered in hagfish secretions all day? If one group of researchers gets their way, then we're looking at the fashion of the future.

The hagfish (which isn’t really a fish in the conventional sense) is a living fossil. It has undergone little to no evolution in the past 300 million years. It has an interesting and effective defence mechanism that can repel even sharks. When threatened, it releases large quantities of protein. This protein, when released into the water, forms threads that turn the immediate environment of the hagfish thick and gooey. The slime, which “smells like dirty sea water”, according to one of the researchers, deters predators from attacking the hagfish.

The researchers have found that the protein threads can be isolated from the slime (via the removal of water and mucous). The protein threads themselves are categorized as ‘intermediate filaments’. Each thread is 100 times smaller than a single human hair. These fine threads can be woven to create fabric that’s as strong as nylon or plastic. With more research, these fabrics could even be used to make clothes! Hagfish produce large amounts of slime in mere seconds. The mere efficiency of this process grants it an advantage over harvesting silk from silkworms. Furthermore, the material is much more sustainable than artificial fibers like nylon and polyester. In the words of the head researcher, Atsuko Negishi, “This work is just the beginning of our efforts to apply what we have learned from animals like hagfishes to the challenge of making high-performance materials from sustainable protein feedstocks.”

The next challenge would be to make the process feasible on an industrial scale. It’s unlikely that slime will be directly harvested from the hagfish in large amounts. Alternatively, the slime-making genes might be transplanted into bacteria, which can be cultured to provide the slime on a much larger and more feasible scale.

More info: http://bbc.in/Z4MXt9