BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Earth

Warmer Winters, Less Lake Ice

 

Royalty-Free photo: Ice, glacier, frozen, cold, glacial ice, air inclusions | PickPik

Crystalline Lattice Ice

An article written in the ScienceDaily explores recent concerning data: due to climate change, lakes in the Northern Hemisphere are experiencing “more ice-free years.” You may be wondering—well, why does the amount of ice on a lake matter? The dwindling ice on our Earth’s lakes is not only a wake up call for our climate sensitive present and future, but also an indication of the detrimental ecological, cultural, and economic impacts of climate change.

I used to take ice for granted; now I understand why it is truly a unique thing. Water is one of the only substances that is less dense as a solid than as a liquid. This phenomenon is due to its hydrogen bonding. As temperatures fall below 4 degrees celsius, water molecules move too slowly to break these hydrogen bonds. As a result, the molecules are able to form a crystalline lattice, making the most amount of hydrogen bonds possible, 4. This property is crucial for life under ice to exist on earth, and therefore, crucial to the balance of all life on earth. Now, with a changing climate, ice is at risk. 

In a recent study, researchers analyzed 80 years of lake ice data from 1939-2016. Focusing on 122 lakes that have historically froze every winter, the researchers concluded that ice-free years for these lakes were 3 times more frequent since 1978. This trend is highly correlated with abnormally warm winters, and it will continue to increase as the earth warms at higher rates. 

The absence of ice on these lakes has various implications. Communities around the lakes that have traditionally depended on lake ice for ice fishing and ice festivals during the winter are paying the consequences. In addition to economic and cultural impacts, there are also ecological implications. The lakes are warmer in years without ice, and, as a result, they stratify earlier. The formation of distinct thermal layers increases the lake’s susceptibility to toxic algal blooms, which can be harmful to marine life and to people. 

File:Algal bloom(akasio) by Noctiluca in Nagasaki.jpg

Toxic Algal Blooms

 The authors noticed that this warming trend was not unique to a specific location of lakes, but rather, applicable to a broader region of Earth’s lakes. In a new study, researcher Filazzola and his colleagues looked through a broader geological lens to understand how the frequency of ice-free lakes has changed over time. They gathered consistent historical and modern data from the National Snow and Ice Data Center (NSIDC) for 122 lakes in North America, Europe, and Asia. Some of the oldest data collected was from 1443 about Lake Suwa, located in Japan. At this historic lake, the researchers collected impressive documentation from 15 generations of priests, who have always regarded the lake’s ice with “celebration.” Again, this demonstrates the cultural significance that lake ice holds in many communities. 

File:180205 Lake Suwa omiwatari 03.jpg

Lake Suwa, Japan 

Overall, Filazzola and his colleagues concluded that there is a correlation between air temperatures/climate cycles and increasingly “ice-free years,” which they defined as a lake not having “100%” of ice coverage “for at least one day.” Their data clearly demonstrated that lake warming is more prevalent in the last 40 years than in the last 80 years. One of the researchers, Sharma, even called the growing absence of ice as “not normal” and “a historical snapshot to understand that the climate is changing.”

As a 17 year old in today’s world, I feel very strongly about earth’s changing climate and its negative effects for our future. While the subject has become politicized in the United States due to certain industrialist economic beliefs, our changing climate is indeed pressing and sensitive. It is our duty as stewards to protect the planet and to moderate its changing climate.

How a Dash of Salt in the Summertime Helped Bring About Life on Earth

As humans, one of the most challenging and provocative questions we can ask is how life on earth came to be. We know about evolution, survival of the fittest, the one fish brave enough to walk. But how did the first microorganism suddenly wriggle its way out the world of the inanimate and mark the beginning of life on earth? Researchers from Saint Louis University, the College of Charleston and the NSF/NASA Center for Chemical Evolution think they have a new clue regarding the Earth’s environment at the time, and it sounds a lot like barbeque and pool party weather!

One of the keys to the creation of life is proteins. Proteins are strings of amino acids held together by peptide bonds, and they are responsible for carrying out countless tasks in the cell from catalyzing reactions as enzymes to protecting against diseases as antibodies to controlling movement and muscle contractions. Previous research has found that subjecting amino acids to “repeated wet-dry cycles”creates an ideal environment for the formation of peptide bonds. The more peptide bonds, the more complex polymer proteins that form and carry out biological processes needed for sustaining life. According to our original article, “Were hot, humid summers the key to life’s origins,” scientists imagine that the pre-life climate on earth consisted of hot, sunny days broken by heavy rainstorms. However, when Luke Bryan said that “rain is a good thing,” I don’t think he was referring to the cultivation of peptide bonds, because too much rain can actually have an opposite effect on our pre-biological proteins.

Pictured above is two amino acids joining to form a dipeptide through dehydration synthesis (removing an H2O molecule to join two monomers)

While water is the basis for all biological function, too much water added to a solution can result in hydrolysis, the decomposition of polymers due to the insertion of water molecules between bonds. If the Earth’s early climate involved large rain storms, the rain would flood the amino acid mixture and prevent the formation of peptide bonds. So, what kind of climate would then be required to spark the creation of life? Angela M. Hessler, in her article “Earth’s Earliest Climate,” tells us that “evidence points to an unfrozen — perhaps balmy — Archean Earth” due to “100–1000 times more CO2 than present atmospheric level,” which gives the Earth a “greenhouse atmosphere.” This greenhouse climate consists of high temperatures and humid weather- basically summer weather! This humidity in the air allows the amino acids to receive the ideal amount of water for forming complex proteins. However, our researchers have also discovered another factor that aids the formation of proteins, the process’s own sort of catalyst that pairs perfectly with the humid climate of pre-biological Earth.

Deliquescent minerals are salts that absorb humidity out of the air and then dissolve. If deliquescent minerals are present while amino acids bond into polypeptides, they can regulate the wetness of the environment in which polypeptides form, creating a perfect environment for the creation of proteins! I guess we can take the Bible that much more literally when were were told, “For you were made from dust, and to dust you will return.”

Above is dipotassium phosphate, a highly deliquescent mineral that is likely to have been present during the first formation of polypeptides millions of years ago.

While to some it may seem inconsequential, this discovery is important! Think about it: whenever we talk about evolution, we talk about inheriting traits from our ancestors. But we never talk about our oldest ancestor. The ancestor that has no ancestors because they are the first thing to live on this Earth! This discovery gives concrete evidence for a plausible theory regarding the birth of life on this planet, that one cell that fathered everything that now sees and breaths and strives to reproduce. This article gives us the farthest glimpse possible into the past, and with this new information, we can start to learn more about how life rose from the ground to survive and thrive on Earth.

If you have any other ideas or remarks, please feel free to comment on this post! I would love to hear what you all have to say about this exciting, new discovery!

 

Global Warming can alter the shape of the planet

Climate change is an element in our world which has been around for many years. It has been believed to cause warmer oceans and erratic weather, but a new study, according to scientists, declares it also has the potential to alter the shape of the planet we live in. Global Warming is a gradual increase in the overall temperature of the earth’s atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants. (read more about Global Warming) Michele Koppes,  assistant professor in the Department of Geography at the University of British Columbia, conducted a five year study in which she compared glaciers in Patagonia and in the Antarctic Peninsula. Koppes and her team discovered that glaciers in warmer Patagonia moved faster and caused more erosion than those in Antarctica, as warmer temperatures and melting ice helped lubricate the bed of the glaciers.

global warming

 Glaciers erode 100 to 1,000 times faster in Patagonia than they do in Antarctica.   “Antarctica is warming up, and as it moves to temperatures above 0 degrees Celsius, the glaciers are all going to start moving faster,” states Koppes. These ice sheets are apparently beginning  to move faster and should become more erosive. As a result, this will dig deeper valleys and shed more sediment into the oceans. The outcomes of this erosion add to the already complex effects of climate change in the polar regions.  “The polar continental margins in particular are hotspots of biodiversity, If you’re pumping out that much more sediment into the water, you’re changing the aquatic habitat,” Koppes states.  The Canadian Arctic, one of the most rapidly warming regions of the world, will most definitely feel these effects. These glaciers are on the verge of a major shift. The Canadian Arctic is becoming warmer in temperature more than four degrees Celsius spanning over the last 50 years. These glaciers will be flowing up to 100 times faster if the climate continues to shift and shifts above zero degrees Celsius. The findings by Koppes settle a scientific debate about when glaciers have the greatest impact on shaping landscapes and creating relief, suggesting that they do the most erosive work near the end of each cycle of glaciation, rather than at the peak of ice cover. If global warming continues to occur, change in formation of landscape due to higher water levels from melting glaciers is a strong possibility and may already be taking place. This will significantly affect all forms of life on earth.

 

Original Article:  http://www.sciencedaily.com/releases/2015/10/151001142222.htm

Citations:

http://www.whoi.edu/main/topic/global-warming

http://www.sciencedaily.com/releases/2015/10/151001142222.htm

 

Genome Project Helps Connect Ethnicity to Diseases

Though people from all over the globe share over 99% of the same DNA, there are subtle differences that make us all individuals

Scientists at the Washington University School of Medicine in St. Louis have started the “1,000 Genomes Project” in which they will decode the genomes of 1,000 people from all over the world in hopes of finding genetic roots of both rare and common diseases worldwide. On October 31st, the results of DNA variations on people from 14 different ethnic groups were published, but the scientists hope for the project to expand to involve 2,500 people from 26 different world populations. According to Doctor Elaine Mardis, co-director of the Genome Institution at Washington University, “[scientists] estimate that each person carries up to several hundred rare DNA variants that could potentially contribute to disease. Now, scientists can investigate how detrimental particular rare variants are in different ethnic groups.”

 

We are One

Everyone on earth share 99% of the same DNA. That means you, your best friend, your mortal enemy, your boyfriend/girlfriend, next door neighbor, and The President of the United States all share 99% of your DNA. However, there are rare variants that occur with a frequency of less than 1% in a population that are thought to contribute to both rare diseases and common conditions (i.e cancer, diabetes). The rare variants explain why some medications do not effect certain people or cause nasty side effects (i.e insomnia, vomiting, and even death).

 

The goal of the “1,000 Genomes Project” is to identify rare variants across different populations. In the pilot phase of the program, researchers found that most rare variants different from one population to another, and the current study supports this theory.

 

The Study

Researches tested genomes from populations from the Han Chinese in Beijing (and the Southern Han Chinese in China) to Utah Residents with ancestry from Europe to the Toscani people of Italy to the Colombians in Columbia. Participants submitted an anonymous DNA sample and agreed to have their genetic material on an online database. Researchers than sequenced the entire genome of each individual in the study five times. However, decoding the entire genome only detects common DNA changes. In order to find the rare variants, researchers sequences small portions of the genomes about 80 times to look for single letter changes in the DNA called Single Nucleotide Polymorphisms, or SNPs.

 

The Results and Importance

The Study concluded that rare variants vary from one population to another. Researchers found a total of 38 million SNPs, including 99% of the rare variants in the participants’ DNA. In addition, researchers found 1.4 million small sections of insertions or deletions and 14,000 large sections of DNA deletion. The “1,000 Genomes Project” is incredibly important in medical science. It now allows researchers to study diseases, such as cancer, in specific ethnic groups. I personally think this project in incredibly important. As an Ashkenazi Jew from Eastern Europe, my family has a medical history of certain cancers and diseases. With the results of the “1,000 Genome Project,” researches could potentially find out why, and maybe even find a cure for some of these diseases.

Hartley 2, The Stork of Earth’s Water

You may remember what you were told about how water came to be on earth when you were younger.

Photo Credit: Creative Commons by AndyRobertsPhotos

Perhaps your siblings suggested that you cried so much you made the Atlantic. Perhaps that strange man your parents don’t like confided in you that water is merely a government conspiracy. Perhaps your elementary teachers assured you that you would learn about it when you were older. Well, the answer (or part of it, at least) is here. And the answer is: Comet Water.

A recent finding by researchers suggests that part of the world’s water supply may have been delivered by comets. To this day, only six comets have ever been detected with water on its surface. This new comet, named Hartley 2, was found with ice by scientists using the Herschel Space Telescope. What makes Hartley 2’s ice so profound compared to the other comets with water, has to do with their molecular composition. The other comets’ water had a ratio of deuterium to hydrogen that did not match up with the molecular composition of earth’s water. This suggests that those comets were not the source of earth’s water. Scientists believe that the ratio of these other comets did not match because they came from something called the Oort cloud. Hartley 2, is believed to have come from the Kuiper Belt which is “1,000 times closer to earth [than the Oort cloud]” This closeness seems to be the reason that Hartley 2’s ice is a molecular match for the water on earth.

With this finding, other comets can be compared to Hartley 2’s composition and determined as a match. However, with this exciting new finding also comes the promise of much more work in the future. Paul Hartogh, who works for the Max Planck Institute for Solar System Research in Germany, hints that: “This finding means that models of the formation of the solar system may have to be revisited.” 

Do you think that finding a possible source for earth’s water is worth re-thinking many current scientific knowns? Were you surprised that a comet could be a credible source of earth’s water? Don’t hesitate to comment below, I’m sure everyone would like to be updated on the research about this topic. And remember, with this new found knowledge you have to power to educate others about a true source of earth’s water.

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