Briggs, Helen. “DNA from Stone Age Woman Obtained 6,000 Years On.” BBC News, BBC, 17 Dec. 2019, www.bbc.com/news/science-environment-50809586.

Erin Kaye

1/23/19

AP Biology

Current Event 14

Briggs, Helen. “DNA from Stone Age Woman Obtained 6,000 Years On.” BBC News, BBC, 17 Dec. 2019, www.bbc.com/news/science-environment-50809586.

The article “DNA from Stone Age Woman Obtained 6,000 Years On” was written by Helen Briggs and published in the BBC. Scientists were able to obtain the DNA from a woman from a piece of “chewing gum,” which is tar from a tree. This is important because there are no other human remains from this time period. This also marked the first time an entire human genome was extracted from anything other than bone. The code was used to decipher what the woman looked like and it is likely that she had dark skin, dark brown hair, and blue eyes. She is more genetically related to the hunter-gatherers of mainland Europe, than to those who lived in Scandinavia. This tells us that she was likely descended from a population of settlers that moved to western Europe after the glaciers retreated. She could have possibly lived on Syltholm on Lolland, an island of Denmark. From the DNA we can also learn that her diet at the time consisted of hazelnut and mallard. The researchers extracted the DNA from microbes attached in the tar, where they found pathogens that cause glandular fever and pneumonia as well as other natural viruses and bacteria. This information is important because it offers information on people’s lives, ancestry, livelihood, health, and how human pathogens have evolved.

This article could have a strong effect on society because it can tell us about history, ancestry, livelihood, health, and how human pathogens have evolved. This is important as quoted from Dr. Schoeder because “we can study how they evolved and how they are different to strains that are present nowadays. And that tells us something about how they have spread.”

Briggs did a very good job quoting different researchers on their thoughts on this study. This added validity and made it more interesting to read. Briggs also did a good job including different subtopics, which made the article easier to follow. Briggs could have improved their article by placing the pictures included under the subtopics or paragraph they correlated to. The fact that the pictures were placed randomly disrupted the flow and understanding of the reader.

A replacement for exercise? A protein called Sestrin might be responsible for many of the benefits of a good workout

Ava Chiang 

1/13/20

AP Biology 

Current Event Review #13

Michigan Medicine - University of Michigan. "A replacement for exercise? A protein called Sestrin might be responsible for many of the benefits of a good workout." ScienceDaily. ScienceDaily, 13 January 2020. <www.sciencedaily.com/releases/2020/01/200113075830.htm>. 

In the article "A replacement for exercise? A protein called Sestrin might be responsible for many of the benefits of a good workout” a study on exercise conducted by a team at the University of Michigan discovered sestrin, a protein that mimics the effect of exercise in flies and mice. Myungjin Kim, Ph.D., a research assistant professor in the Department of Molecular & Integrative Physiology says that "Researchers have previously observed that Sestrin accumulates in muscle following exercise.” However, currently, scientists don’t know why or how sestrin occurs. 

What the team discovered was that when sestrin levels were overexpressed in flies muscles, those flies had flight abilities above the control group flies (regular flies) even without exercise. Additionally, mice without sestrin were discovered to lack “the improved aerobic capacity, improved respiration and fat burning typically associated with exercise.” Currently, the UMichigan scientists are working with Pura Muñoz-Cánoves, Ph.D., of Pompeu Fabra University in Spain to use sestrin in treatment for muscle atrophy. 

Muscle atrophy can occur with aging and with disuse, such as long term illness or injury. If sestrin, a protein said to be able to mimic the benefits of exercise to bodies without any physical movement, can be used in treatment with athletes, military personnel, and patients then it may shorten recovery time. It could also potentially be a cure for diseases that actively cause muscle atrophy such as Lou Gehrig’s Disease (ALS). Currently, diseases like ALS has no cure, only medication and therapy that can slow it down. Malnutrition due to physical reasons or mental illness (ex: eating disorders) also cause irredeemable damage to the body, sestrin used in treatment may help make a difference. 

Strengths of this article includes citation of multiple notable figures committed to this study, this adds credibility to the results. The results of experiments on two types of organisms (mice and flies) were also included to create a bigger picture of the studies. Weakness of the article includes not having a conclusive idea on how sestrin is produced naturally and if it could be produced manually or artificially. There is also no guarantee that sestrin is found in humans since the study did not include humans yet. An improvement for this article would be to wait until there’s more conclusive evidence that sestrin can be used in human treatment before publishing. However, this was a very informative article and very interesting to read.

“Australian Fires Have Incinerated the Habitats of up to 100 Threatened Species.”

Olivia Conniff

Mr. Ippolito 

AP Biology

12/13/20

Current Event 13

Pickrell, John. “Australian Fires Have Incinerated the Habitats of up to 100 Threatened Species.” Science News, 12 Jan. 2020, www.sciencenews.org/article/australian-fires-incinerated-habitats-threatened-species-ecological-disaster.

For my 13th current event, I chose to read the article “Australian Fires Have Incinerated the Habitats of up to 100 Threatened Species” by John Pickrell. Pickrell describes the current situation in Australia, where, as of yesterday, nearly 11 million hectares of land have been burned by the bushfires which have been going on for months. Over 2,200 homes have burned to the ground and 29 people have been killed, and there are still two months of this season of fires left. Australia is certainly no stranger to wildfires, as they typically experience them around this time of year, but never of this caliber. These bushfires are particularly bad due to a combination of extreme heat, prolonged drought, and strong winds. The country is also in the middle of an immense heatwave, in mid-December having its hottest day in history. The cause of this is global climate change. These bushfires are a prime example of the catastrophic effect climate change is having on the planet. Christopher Dickman, an ecologist at the University of Sydney provided that information that over 1 billion animals have been killed so far. However, this number does not even include bats, frogs, and invertebrates. “Invertebrates make up more than 95 percent of animal species and the vast majority of animal biomass,” says Mike Lee, a biologist at the South Australian Museum in Adelaide. This means that invertebrate losses alone could be in the trillions. Many habitats have been completely decimated as well, which will cause effects that will carry on even after the fires are long over. “We haven’t seen a fire season like this ever before,” says Euan Ritchie, an ecologist at Deakin University in Melbourne. “Climate scientists and ecologists predicted these worse fires as a result of climate change and we’re now seeing them happen.”

The subject of this article is extremely important, as these bushfires in Australia are very present in the news right now, and are a prime example of the disastrous effects of climate change. From hearing just how terrible the conditions in Australia are right now, it is clear that we need to take bigger steps in order to slow the effects of climate change and protect our planet. One may think that as an average person, there are not many things we can do to limit carbon emissions as most of them come from industry and agriculture, but there are actually many small things that can be done, that if enough people do them, can make a difference. Transportation makes up for a whopping 29% of carbon emissions, meaning that if we try to use more public transportation, walk places, or bike places, we are actually helping to do our part. Electricity also makes up for 28% of carbon emissions, meaning if we try to shut off lights or other appliances anytime we don’t need them on, we are helping. These may seem like trivial, useless things but if we all try to do our part we can make a difference. That is why this article is so important and relevant because it can inspire people to try to do better to protect the planet.

For the most part, I believe that Pickrell’s article is very well-written and effective at communicating the intended message. He uses quotes from experts as well as reliable statistics, which make the article a lot more professional and credible. He keeps his descriptions concise and clear, not including irrelevant information, merely to fill the page. He also included a great deal of background information on fires in Australia in the past which I found extremely helpful and informative. One thing I believe could improve the article would be if Pickrell included more background information on the climate crisis itself, as I had to go to some outside sources to find this information. Other than that, I thoroughly enjoyed Pickrell’s article.

Some People with Half a Brain Have Extra Strong Neural Connections

Mariana Apostolatos 

Mr. Ippolito

January 13, 2020

Current Event 13

Sanders, Laura. “Some People with Half a Brain Have Extra Strong Neural Connections.” Science News, 19 Nov. 2019, https://www.sciencenews.org/article/some-people-with-half-brain-have-extra-strong-neural-connections.

According to a recent article by Laura Sanders, some people with half a brain have extra strong neural connections. Sanders described a study of six adults who, as children, had half of their brain removed to treat severe epilepsy. This study revealed how brains can reorganize and bounce back. She continues by stating that as extreme as the surgery is, most people keep or recover language and thinking skills. Sanders then offered evidence from a new study from Caltech. During the study, while the six participants rested in an MRI scanner, researchers measured blood flow in seven brain regions that handle jobs such as vision, attention and movement. Sanders explains that in the experiment, “blood flow served as a proxy for brain activity” and “when activity in one part of the brain changes in lockstep with activity in another, that implies that the regions are working together and sharing information.” These strong connections offer evidence of a healthy brain. In fact, this study revealed that the connections between those seven systems were even stronger than such connections in six people with whole brains. 

Understanding more about how the brain reorganizes itself after a big change could lead to new approaches to speed people’s recoveries from common brain injuries. The brain is one of the largest and most complex organs in the human body. It is made up of more than 100 billion nerves that communicate in trillions of connections, controlling our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body. The fact that the people with half a brain could function no differently than those with a normal brain is an astonishing discovery and can lead to the cure of more brain injuries. 

This article was very well written and informative. It was very easy to read and follow, even providing an image of an MRI scan of half a brain. All of the information was introduced in chronological order and the author was very straight-foward and to the point. However, I felt that the article was lacking some information that could have helped deepen a reader’s understanding. The article was very short and I wished the author went more in depth about how this discovery could lead to new approaches to speed people’s recoveries from common brain injuries. The author didn’t explain specific connections this discovery will have on society. Overall, the article was easy to understand, engaging, and not too long, keeping the information relevant and to the point.

DNA From 5,700-Year-Old ‘Gum’ Shows What One Ancient Woman May Have Looked Like

Rory Christian
Mr. Ippolito
12/9/20
Current Event 13

Bates, Sofie. “DNA from 5,700-Year-Old 'Gum' Shows What One Ancient Woman May Have Looked Like.” Science News, 17 Dec. 2019, www.sciencenews.org/article/dna-5700-year-old-gum-may-reveal-ancient-woman-appearance

Researchers say that chewed gum could be an overlooked source of ancient genetic material. On December 17, researchers reported in Nature Communications that chewing gum "can hold enough DNA to piece together the genetic instruction books, or genomes, of long-dead people" (Bates). After looking at a 5,700-year-old piece of gum from Denmark, researchers were able to determine the genome of an ancient woman, determining that she most likely had blue eyes, dark skin, and dark hair. The "gum" they chewed, the reported, was birch pitch, or heated birch bark. By repeatedly chewing this gum, mouth cells were worked deep into the substance. The birch bark, researchers discovered, is relatively resistant to bacteria, viruses, and water, which was what preserved the gum and protected the DNA from decay for that long. In addition, the researchers discovered DNA from microbes that had previously lived in the woman's mouth. The microbes included older versions of the Epstein-Barr virus and bacteria that have caused pneumonia. Remnants from a meal the woman ate before chewing the pitch were identified, as researchers traced the DNA of duck and hazelnut in the gum. This discovery was "kind of like a snapshot of one moment in time" says Hannes Schroeder, a geneticist at the University of Copenhagen, as information about ancient microbes has been previously found from dental plaque of fossilized teeth (Bates).

This discovery is immense in its relevance to archaeology and ancient humans. Understanding how our ancestors lived provides insight into what life was like at that time. Learning about the diet of our distant ancestors can help modern humans formulate better eating habits and control weight and reduce the risk of diabetes, heart disease, asthma, and other disorders. In addition, it has always been a competition to find out what prehistoric humans looked like for the purposes of science and research.

This article did a great job explaining the findings of the discovery such as microbes and disease. In addition, the use of quotes in the article successfully built upon the results of the study by providing outside insight on the topic. However, I wish the article had elaborated on the significance of the discovery as it related to current science. In addition, the article lacked a lot of the explanation behind how they determined the woman's diet and physical features; I am still confused on this aspect.

Sarah Whitney

Mr. Ippolito

1/5/20

Current Event 12

Lambert, Jonathan. “Climate Change Is Bringing Earlier Springs, Which May Trigger Drier Summers.” Science News, 3 Jan. 2020, www.sciencenews.org/article/climate-change-bringing-earlier-springs-may-trigger-drier-summers.

Due to climate change, winters are becoming shorter, Spring is arriving early, and this causes scientists to worry that this will lead to dry summers. “But when this greening starts earlier in the calendar year, scientists worry that more moisture could be sucked from the soil than if the season starts later.” This, in turn says Lambert, could lead to more frequent and intense heat waves. One study even found that the growing season has extended by about 10 days in the Northern Hemisphere over the last 3 decades. “More green on the ground causes evapotranspiration to go up,” says Chris Huntingford, a climate modeler at the U.K. Centre for Ecology and Hydrology in Wallingford, England. But it wasn’t clear if a local increase in water being pumped into the atmosphere due to evapotranspiration would be offset by rain falling back to Earth, or whether certain geographic areas might be more affected than others.” Dry soil may have serious consequences including raising air temperature and could raise maximum temperatures there by 0.07 degrees Celsius per decade.

This is extremely relevant to us as although this seems like a small issue for now, in a few years we may have incredibly intense heat waves stronger than what we’ve seen before. This could include even more destructive fires like the ones we’re seeing in Australia right now. Climate change is extremely worrisome to my generation as this is our future at risk.

This author was very clear about the study and its results however, I wish he would have gone in more depth about how exactly it was conducted and how the scientists went about determining the numbers they did.

Amanda Troy 

12/19/19

AP Biology
Current Event 12

Saey, Tina Hesman. “Prions Clog Cell Traffic in Brains with Neurodegenerative Diseases.” Science News, 11 Dec. 2019, www.sciencenews.org/article/prion-proteins-clog-cell-traffic-brains-neurodegenerative-diseases.

For my current event, I read an article titled, “Prions clog cell traffic in brains with neurodegenerative diseases” by Tina Hesman Saey. This article discusses a new study revealing clumps of misfolded proteins causing traffic jams in brain cells. These jams may have deadly impacts in neurodegenerative diseases. Tai Chaiamarit, a cell biologist at the Scripps Research Institute in La Jolla, California, reported clusters of prions blocking passage of “crucial cargo” along intracellular roadways in brain cells. Prions are misshapen versions of a normal brain protein, grouped together in big aggregates that are “hallmarks” of degenerative diseases. Axons are long projections of nerve cells that carry electrical signals to other nerves. Chaiamarit and other colleagues found that Axons are the sites for prion traffic jams.  As more prions clump together, they result in swollen bulges that make the axon, “look like a snake that has just swallowed a whole meal” (Hesman, 1). Prion clumps disrupt outbound traffic, causing kinesin-1 and mitochondria to jump the microtubule tracks in the swollen sections, the researchers discovered.

Brain cells are alive before the traffic jam starts. As stated before, the protein traffic jams may have deadly impacts in neurodegenerative diseases. Based on these new findings, researchers believe that the  jams can result in cell death later on. It is still unclear as to why these clumps of proteins are harmful to neurons, but this new study may provide insight into what actually goes wrong in neurodegenerative diseases. This is something that will impact our society in an immensely positive way. 

The article’s main strength was the comprehensive explanation of the science behind the new study which included findings of prion proteins and axons. The article also utilized metaphors when explaining the different aspects behind the science in order to relate to the reader and make the study easier to understand, such as when the axon was compared to a snake that has just swallowed its meal. Something that I wish the article did was go into more depth on what impacts this will have on our society. This is something that was briefly mentioned, but it something that could have been elaborated on and would have created a more intriguing, eye-opening article.