Tag Archives: climate

Will the Woolly Mammoth Be the First Animal to Become De-Extinct?

Over the last decade, there’s been quite a debate about whether or not, and perhaps more importantly whether or not we should, clone the woolly mammoth back to life. So far, researchers have made some progress on the first question at least. Back in 2005, the Mammoth Creation Project suggested that a creature with 88 percent resemblance to extinct species of mammoth could be cloned successfully within the next 50 years. Already, they may have their first major breakthrough in the processes of cloning.

One of the most prominent geneticists in the United States has successfully managed to extract DNA out of the frozen remains of a frozen mammoth discovered at Wrangel Island in the Arctic Ocean. Although the original strands of DNA are long dead, there was enough genetic information on the animal, which was well preserved with skin and hair, to build a synthetic replica which they then implanted inside the cells of an Indian Elephant – the mammoth’s closest living relatives, which are also about the same size. The elephant cells were kept isolated inside a petri dish. With the aid of a revolutionary (and somewhat controversial) DNA splicing technique known as CRISPR that allows for unprecedented accuracy, which allows for editing genes and even spreading them to the next generation. Lead researcher George Church, of Harvard University, has proudly reported that so far the cells are doing quite well.

The woolly mammoth died out some 10,000 years ago on the mainland in North America, roughly two millennia after mammoth species died out in Europe. The smaller ones indigenous to Wrangel Island, however, lived on peacefully without our intervention until about 1650 BC, overlapping with the rise of civilization in ancient Egypt and the construction of the oldest pyramids at Giza. Before then, they had dominated the Earth for 250,000 years during the Pleistocene Age, thriving during the last of Earth’s five major ice ages, when the planet was between nine and eighteen degrees Fahrenheit colder than it is today. This climate is the primary reason that mammoths, mummified under layers of snow and ice are so easy to find in prime condition, particularly as the Siberian permafrost thaws. Some have even revealed what their fur looked like. So plentiful were the carcasses at one point, that the 1951 Explorers’ Club’s annual dinner in Manhattan actually offered small morsels of mammoth meat for appetizers.

As temperatures became warmer and sea levels began to rise once again, life became a bit harder for the woolly mammoth, particularly around 18,000 years ago, when tribes of hunter-gatherers grew bigger and more organized, successfully hunting them down in large numbers. While Church and his team of researchers were not yet able to fully replicate a complete woolly mammoth genome so what they did was make copies of the genes responsible for the ‘mammoth-like’ attributes that we know – like heavy layers of fat to protect against the cold climate, the ears, which are actually shorter than the ones on modern elephants, tusks, and heavy coats of fur.

“We prioritised genes associated with cold resistance including hairiness, ear size, subcutaneous fat and, especially haemoglobin,” Church revealed to Ben Webster of The Sunday Times. Hemoglobin may have been the key genetic ingredient in helping mammoths tolerate extreme winters. Regardless of the temperature, this protein managed to keep oxygen traveling to the muscles at a constant speed, and may have allowed the mammoths to develop cooling systems for their limbs. By comparison, the hemoglobin in modern elephants, like humans, functions better in warm weather.

While there are samples of flesh and hair that would seem like natural reservoirs for DNA, the trouble is that the meat that has been found is thoroughly rotten, and while the fur shows an orange color, paleontologists have had to adjust the colors they’ve found for what may have been damage to the pigments from being trapped for so long under the ice. Another problem is that many of the mammoths born later clearly suffered birth defects. Cervical ribs that appear in some of the later females may have led to reproductive stress, joining overhunting and climate change as a possibility for their gradual decline.

While people have certainly played at least a partial role in the animal’s disappearance, our technology may eventually bring them back. According to Church: “We now have functioning elephant cells with mammoth DNA in them. We have not published it in a scientific journal because there is more work to do, but we plan to do so.” If successful, we may soon see the first mammoth in nearly 3,300 years.

The technique that combines elephant DNA with the extinct mammoth genome is CRISPR/Cas9, which has lately been used to develop transgenic organisms with an impressive track record. This marks the first time, however, that the technology has taken on the DNA of an extinct organism.

The researchers will next work to determine the best way to reproduce their work with elephant cells outside of the petri dish. It’s actually quite a tall order, but if they are somehow able to this with the use of elephant eggs, then they just might be able to program an elephant that will grow up to be just like a woolly mammoth. The question, however, is whether doing so would be a good idea. De-extinction is a point of contention among many researchers. Not all of them are quite enthusiastic about the idea. According to biologist Alex Greenwood from the Leibniz Institute for Zoo and Wildlife Research, in an interview with The Telegraph:

“We face the potential extinction of African and Asian elephants. Why bring back another elephantid from extinction when we cannot even keep the ones that are not extinct around? What is the message? We can be as irresponsible with the environment as we want. Then we’ll just clone things back?

Money would be better spent focusing on conserving what we do have than spending it on an animal that has been extinct for thousands of years.”

He certainly raises some good points. There are only a few rhinoceroses and a continuously declining population of iconic wildlife throughout Africa, elephants and even the predators like lions suffering from disease. The woolly mammoth would be returning to the world, entering an ecosystem that has adapted to thousands of years of life without them, and require a specialized diet. If we’re already having problems with spreading populations of invasive species, then bringing back extinct species might create an entirely new headache.

On the other hand, many grasslands in North America are showing the impact of having lost their larger grazers such as the megatherium (a bear-sized sloth), 18,000 years after the fact. Perhaps there is the promise of some ecological stability taking place, or perhaps further cultivating the mammoth genome may lead to further improvements in the technology of gene editing. If not an extinct species, perhaps this experiment might also lead to focusing on the preservation of species that only recently died out or those currently extinct in the wild, such as the black rhinoceros. We might be too late in having a thorough debate on the matter anyway, as Church’s team is only one of three research teams in the world actively at work on bringing back the woolly mammoth, but the fact that the issue has been raised alone is important, if only for bringing to the table new ways to preserve already endangered species.

James Sullivan
James Sullivan is the assistant editor of Brain World Magazine and a contributor to Truth Is Cool and OMNI Reboot. He can usually be found on TVTropes or RationalWiki when not exploiting life and science stories for another blog article.

What a Prehistoric Whale Skull Can Tell Us About the Birth of Humanity

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Paleontologists are inching closer to the exact spot where modern day Homo sapiens first originated, and they found help through a rather unlikely clue. The fossilized skull of a whale that lived 17 million years ago is drawing them to humanity’s origins in East Africa. Here’s how:

The whale, classified as Ziphiidae, existed at a time when warm climates brought the East African plateau considerably lower than it is today. Unlike the dry grasslands it is today, this region was then hidden under dense foliage, according to the researchers. At some point it lifted far above the sea, pushing away much of the moist winds that these jungles were dependent upon – drying the land into a savannah. For scientists, it’s really been a question of when this separation between the plateau and the Indian Ocean took place.

Our distant ancestors may have swung from trees in the East African jungles, but as the trees died out in favor of grasses, our ancestors began the transition to walking upright on two legs, suggests the new research.

“It’s more or less the story about the bipedalism,” said study researcher Henry Wichura, a postdoctoral geoscience student at University of Potsdam in Germany.

The discovery of a skull belonging to a beaked whale, ziphiidae, buried in the rock layers has now allowed scientists to pinpoint the dates when the plateau began rising – sometime in the Pliocene – between approximately 17 million and 13.5 million years ago.

The whale skull was first discovered over 50 years ago – found by fossil hunters back in 1964 is one of rediscovery. Researchers originally found the fossil in 1964, but no studies were conducted on it for another decade. Then, the skull was misplaced, hidden in a museum archive at Harvard University until 2011. Surprisingly, it was discovered in the former office of the legendary paleontologist and science educator, Stephen Jay Gould. According to the study, it was placed there for safe keeping when the school’s archives were undergoing renovations.

The skull’s provenance is a bit more important than its discoverers first imagined. It is the oldest known fossil of a beaked whale, a rather puzzling discovery if you consider that these animals are actually deep sea divers. The fossil was uncovered 460 miles (740 kilometers) inland from the modern East African coast, and at 2,100 feet above sea level.

When it was alive, Wichura’s beaked whale grew to be 23-foot-long (7 m), swimming in the Indian Ocean. One day, however, he accidentally swam into a river towards present-day Kenya, where he eventually became trapped before his death.

“We came to the idea that it used a large river system, because the whale had been found in lake sediments which are [mixed with] river sediments,” Wichura said. “So we can say that it died in a kind of river-lake environment.”

The story might sound strange – a whale in a riverbed, but crazier things have happened. There are five known species of dolphin who prefer freshwater including the tucuxi, a close relative of marine dolphins that is found exclusively in the Amazon River basin. A sixth species recently became extinct. Back in 2006, a whale got stranded in the Thames River outside London, and killer whales have been found in the Columbia River near the Pacific Northwest. With the rapidly changing sea levels, incidents of this nature may have been more common.

In order to determine the depth of the prehistoric river basin, scientists took the grade of the steepest river out of the area’s case reports, applying its relative depth to the area. Were this 17 million year old river to rise 2.5 inches per mile from the coast, then the East African plateau would be somewhere between 79 feet and 121 feet high when the whale became stranded and died. They kept the difference in height as a variable – allowing that the whale may have chosen several different routes to swim along when entering the river.

Because the plateau is approximately 2,034 feet (620 m) high, the northern part of this plateau was lifted by almost 1,925 feet (590 m) within the last 17 million years.

Somewhere around 13.5 million years ago, Wichura learned that one portion of this land mass had already begun uplifting, giving the researchers a reasonable window into when the uplift started. The researchers were even able to attribute the cause of the uplift – mantle plumes – in which heated material is released from an underwater volcano from the Earth’s mantle and presses against its crust.

Had they not rediscovered the forgotten skull, this dating would have been considerably difficult.

“With the whale, everything started,” Wichura said to Live Science.

The study is a reminder to fossil hunters – both professional and amateur alike – that very often, the precise location of a fossil can sometimes be just as valuable – if not more – than the fossil itself, when it comes to understanding the prehistoric world in full context. The discovery of a single species is hardly significant on its own, but its place in time can reveal information about an entire extinct ecosystem, or even the history of a landscape that was once very different.

“Even single specimens of organisms tell us a great deal about the history of the Earth, and they sometimes appear in surprising cases,” Brown said. “This is one such case.”

This study was published on March 16 in the journal Proceedings of the National Academy of Sciences.

How Carbon Dioxide is Cooking the Planet

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A groundbreaking study has for the first time allowed scientists to witness the direct role that an increase in carbon dioxide (CO2) has on the planet’s greenhouse effect. Scientists at the Lawrence Berkeley National Laboratory (Berkeley Lab) of the U.S. Department of Energy led the researchers in their work, as they first analyzed the heightening capacity of CO2 in our atmosphere to take in any thermal radiation given off by the planet’s surface. For the study they looked at the impact on two different locations on the North American continent over an eleven year period.

While the influence atmospheric CO2 has over the Earth’s energy balance, that is the balance of energy transmitted to Earth from the Sun against the heat expelled from the Earth is well understood and agreed upon by the overwhelming majority of the scientific community, this was the first time anyone has demonstrated such an effect beyond the confines of a laboratory. Their results were published in Wednesday’s online issue of Nature.

The paper agrees with climatologist models of how man-made levels of CO2 will accelerate the greenhouse effect. The sites included in the study were based in Oklahoma as well as the Alaskan North Slope, throughout the years 2000 to 2010. In both locations, CO2 was the culprit for sharp spikes in a phenomenon known as positive radiative forcing – an event in which the atmosphere changes to the degree that it throws the energy balance of the planet off scale. It occurs when the Earth absorbs more solar radiation than what it releases back into space – something that can be measured either from the planet’s surface or high in the atmosphere. For their study, researchers focused on surface temperatures.

The overall consequence of this trend was an increase in atmospheric CO2 by 22 parts-per-million (PPM), much of which was the product of burning fossil fuels. At the moment, CO2 levels hover around 400 PPM, slightly above what are considered generally safe levels, and which will mean an increase in annual temperatures by about 33.5 degrees Fahrenheit. The International Panel on Climate Change (IPCC) and other organizations have aimed for a goal of keeping the levels from reaching 450 PPM, something that could likely happen by the year 2034 if worldwide measures are not taken at once to reduce CO2 levels.

“We see, for the first time in the field, the amplification of the greenhouse effect because there’s more CO2 in the atmosphere to absorb what the Earth emits in response to incoming solar radiation,” said Daniel Feldman, a scientist in Berkeley Lab’s Earth Sciences Division and the paper’s lead author.

In order to observe the increase in CO2 levels over time, the researchers used some of the most precise spectroscopic instruments, operated by facilities of the Atmospheric Radiation Measurement (ARM) Climate Research Facility at the Department of Energy. These instruments based at both sites, read the thermal infrared energy permeating through the atmosphere onto the Earth’s surface, which they then break down into spectral patterns – the signature of the CO2 particles.

These on-location instruments can also pick up and differentiate between which phenomena that are capable of giving off infrared energy, such as any passing clouds or water vapor with chemical components. Using a combination of data from this equipment, the team noticed a gradual rise in the CO2 levels, happening in real time.

“We measured radiation in the form of infrared energy. Then we controlled for other factors that would impact our measurements, such as a weather system moving through the area,” said Feldman.

Over 3,300 measurements were taken from the Alaska location and 8,300 measurements from Oklahoma, which were taken on a semi-daily basis.

The collected data from both sites revealed an identical trend: CO2 levels in the atmosphere emit increasing amounts of infrared energy, an approximation of 0.2 Watts per square meter per decade. While that’s a bit of a hard number to swallow – imagine then that the surface area Earth is about 196.9 million square miles.

A data analysis provided by the National Oceanic and Atmospheric Administration’s CarbonTracker system, the scientists linked this upswing in CO2-attributed radiative forcing to fossil fuel emissions and fires, which have become a growing concern in the Western states.

Another significant find among these measurements was the influence that photosynthesis – the conversion of solar radiation into food by plants – has on the balance of energy on Earth’s surface, which has never been measured in depth. The spring months showed slight dips in radiative forcing due to the growth of plants.