Top Science Stories of 2015

Barak Elal
Mr. Patrick Youell
Science 9A

2015. A year full of headlines; ranging from terrorist attacks, the developement of LGBT rights, and major stories in pop culture. But that wasn't the only news in 2015, as the science community had astonishing discoveries made very much worth the attention of the media. So without further adieu, here are my top 3 science stories of the year!

To begin with, a series of fossil findings in an underground South African cave, which offered potentially key information into the understanding of the origins of the human genus, Homo.

If the discoverers are accurate about their findings then at least some of the early members of the Homo genus held an unexpected mixture of both humanlike and apelike features. This includes legs and feet designed for upright walking, but shoulders, chest, and hips designed for climbing trees. The ancient hominids being examined had brains much smaller than previously anticipated, with skulls shaped like those of later Homo species.

Fig. 1: Bones from more than 15 individuals of the newly discovered species, Homo naledi.

Shifting soil layers inside the cave where the bones were found make it hard to know the precise date which Homo naledi lived, however it is presumed that the remains are from a bit more than two million years ago. It is however possible that the fossils are younger. It is plausible that they belonged to a previously known species, Homo erectus, or perhaps to Australophithecus, another species from the same time period. But the Ethopian jaw which was found is much more dificult to examine, as critics say it is hard to come to any conclusions without any additional bones, as the current ones don't provide enogh information.

Another mind boggling story was the one of Pluto. After being disregarded as a planet not so long ago in 2006, Pluto is now considered to be one of most diverse and complex stars in our solar system. "Pluto is the star of the solar system," according to mission leader Alan Stern.

Pluto's reevaluation came thanks to a robotic spacecraft as large as a grand piano. Following 9 years and 5 billion killometers of travelling, New Horizons reached just 12,500 kilometers from its surface. Once the spacecraft had sent back its first detailed images, it was clear that Pluto was a geologically dynamic planet.

Fig 2: Improvement of images captured of Pluto seen in chronological order of images.

In this geologically rich planet water ice towers thousands of meters over fields of frozen nitrogen and methane, glaciers, and even 2 ice volcanoes appear, as well as new and old terrain; some of it comparably new, some may be as old as the planet it is on. Many things on Pluto are foreign to us, such as the bedrock made of water ice, hardened by the shockingly cold climate of -220°C. Other things are very familiar, such as the blue sky which covers the land.

All of this newly found information has been seen from just 20% of the spacecraft's data, and "Who knows what's going to show up in that 80 percent", says Mark Showalter, a planetary scientist at the SETI Institute in Mountain View, California, and discoverer of 2 of Pluto's 5 moons.

Equally interesting, the study out of Duke University that essentially solved the mystery of human aging, a subject ineteresting many of both the public and scientific community.

The study analyzed the health of almost 1,000 38 year olds, and established that some parallel the health of someone years older, while others the health of someone younger. This biological age was determined by: body mass index, blood pressure, and cholesteral level. The study which tackled a topic with much interest from both the public and the scientific community based itself on the simple question of: why is it that some people live until 120 and others until 70?

Some recent studies have offered some mixed results. Martin Hetzer, a biologist from Salk Institute for Biological Studies in La Jolla, California, concluded that cell systems which outlived brain proteins become damaged over time.  “These are proteins involved in essential cellular functions,” Hetzer says. Brain cells rely on proteins that can survive for an animal’s lifetime, and the breakdown of these cells mentioned could be a clue to the aging sequence.

Another study found that heterochromatin, a bundle of DNA tightly packed in young humans, is not as tightly packed in older people. The study was made on people with with a premature-aging disorder known as Werner syndrome.This change in the 3-D architecture of the genome gives proteins accessibility to stretches of DNA that are not supposed obtainable.

Fig. 3: Normal human stem cells (right), DNA tightly packed into bundles. While those unravelled bundles (left) lead to premature aging, as well as enlarged nuclei in the cells.

Finallly, a third theory is that the body could possibly be aging when essential barriers break down. When young stem cells in the brain divide, they build a wall that sequesters junky proteins into daughter cells. However as the body ages, the stem cells’ ability to produce new cells becomes limited.

As can be seen, 2015 was a year filled with scientific discovery. The diversity of the topic of these studies; the origin of human ancestry, the developement of Pluto as a planet, and the possible discovery of the reasoning behind human aging, proves that the scientific community never fails to provide interesting discoveries, from all departments.

Bibliography:

Fig. 1: https://www.sciencenews.org/article/year-review-early-human-kin-could-shake-family-tree

Fig. 2: https://www.sciencenews.org/article/year-review-pluto-unveiled-world-no-other?mode=pick&context=166&tgt=nr

Fig. 3: https://www.sciencenews.org/article/year-review-not-all-bodies-act-their-age

Crockett, Christopher. "Year in Review: Pluto Unveiled as a World like No Other." Science News. N.p., 15 Dec. 2015. Web.

Rosen, Meghan. "Year in Review: Not All Bodies Act Their Age." Science News. N.p., 15 Dec. 2015. Web.

Bower, Bruce. "Year in Review: Early Human Kin Could Shake up Family Tree." Science News. N.p., 15 Dec. 2015. Web.