Category Archives: Issues in Science

Evolution Can Be More Random Than You Think

Charles Darwin’s Origin of Species postulated that evolution takes a directed approach toward increasing fitness. A recent discovery suggests that evolution doesn’t always need to have a direction. Dr. Matthew Pennell’s findings suggest that evolution on a chromosomal level can have a high degree of randomness.

Dr. Matthew Pennell, an evolutionary biologist specializing in Computational Biology at the University of British Columbia, recently wrote a paper that gives more insight on evolution, entitled Y-Fuse? Sex Chromosome Fusions in Fishes and ReptilesIn this paper, Dr. Pennell uses software and algorithms to determine the factors that drive sex chromosome fusions. Unlike traditional biologists, Dr. Pennell does all of his work on his MacBook instead of using pipettes and microscopes.

Source: Wikimedia Commons, Dr.Pennell uses computational approaches, such as Mathematica for his research.

Source: Wikimedia Commons, Dr.Pennell uses computational approaches, such as Mathematica for his research.

This video, courtesy of universityofbc via Youtub, introduces UBC Killam and NSERC postdoctoral fellow, Dr. Matthew Pennell and talks about his research

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“The simple fact that Y autosome fusions are way more common than W or X or Z, suggests it’s probably just random, which is a kind of interesting and cool result that this huge thing in our genome and across all genomes is just random chance, and this random chance explanation is the most consistent with our data.”

 -Dr. Matthew Pennell

During his graduate studies, Dr.Pennel was part of a team that integrated chromosomal information of thousands of species into an electronic database called The Tree of Sex, which we describe in further detail in our podcast below.

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Now that we know randomness is involved in sex chromosome evolution another question arises: Is sex determination an absolute process? 

As we will soon see there are species, such as the Stickleback fish that change their sex determination system from XY, to ZW, to temperature controlled and so on. However, does this mean that we humans might experience such a change in the future?  

Source: Flickr Commons, Huamns have 22 pairs of autosomes and 1 pair of sex chromosome

Source: Flickr Commons, humans have 22 pairs of autosomes and 1 pair of sex chromosome

“They keep reinventing how they make males and females and this is really interesting and crazy because making males and females is the most basic thing animals do….But they keep switching around how they make males and   females, which I think is pretty cool.”

-Dr. Matthew Pennell

In addition, we were fortunate enough to have the opportunity to interview Dr. Pennell:

Before the interview with Dr. Pennell, our group had a lot of difficulty understanding the premise and messages of the paper. Dr. Pennell provided us with simple insights on the different facets of the evolution of sex chromosomes – from the creative variety of ways that nature determines sex in species, to the mechanisms which drive sex chromosome fusions. Although a lot of these concepts were hard to understand at first, the premise of the paper is very simple to understand – computational biologists often work with real world data sets (ie. “The Tree of Sex”, and try to fit their models to them to determine the relationships between the scientists’ predictions and what’s really happening. In this specific paper, Dr. Pennell and his team concluded that the different models did not relate to the given dataset and the explanation for the real data is attributed to randomness.

 

We would like to give a special thanks to Dr. Matthew Pennell for his time and explanation of his paper.
Authors: Justin Yoon, Julia He, Radu Nesiu, and Matt Golf (Group 2)

The Never-Ending Winter: The Snowball Earth Hypothesis

The history of the planet Earth will always be a mystery that many geologists strive to figure out. In one of my earth and ocean science courses this semester, we talked about the possibility of a Snowball Earth. When I first heard the name, Snowball Earth, I was confused as to what a snowball earth is and why scientists call it that but as the professor began explaining the concept, it became clear.

The Snowball Earth Hypothesis suggests that based on the rock record, the Earth was mostly or entirely covered by ice at certain points over a period of billions of years. Throughout most of the continents today, geologists have found dropstones which are a type of glacial deposits that suggest the presence of ice.

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Glacial Dropstone Source: Michael C. Rygel (WIkimedia Commons)

Dropstones are formed when glaciers move across the land and scratching the surface resulting in the collection of rock pieces. These pieces then combine together and are eventually dropped as the ice melts onto land or into the ocean and are eventually covered by sediments and turned to rock. As these dropstones form, the magnetite particles in the stones reflect the direction of the magnetic field. As a result, geologists have concluded that some of these glacial dropstones were formed at the equator.

Although hard to believe that the Earth can be covered in ice, several factors may have enabled the Earth to be cold enough to have ice at the equator. The first factor was that the sun was not emitting as much energy in the past and therefore the Earth was receiving less heat. Secondly, due to intense rainfall, the CO2 in the atmosphere are drawn down by the rain due to chemical weathering leading to a drop in temperatures.

Quelccaya_Glacier

Quelccaya Glacier Source: Edubucher (Wikimedia Commons)

As temperatures drop, the polar ice caps start advancing towards the equator. As the amount of ice increases, the albedo effect becomes stronger leading to lower temperatures. At this point, I was thinking, how does this make sense since we are not living in igloos today? Well, the answer to that are volcanoes.

Mahameru-volcano

Mahameru Volcano Source: Jurema Oliveira (Wikimedia Commons)

Due to the heat generated by the magma, volcanoes are able to melt through the ice and release many types of gases into the atmosphere such as CO2 and methane. These gases are important because they trapped heat and led to the end of the Snowball Earth. Therefore, over millions of years, these gases accumulated and eventually, the planet was hot enough to melt the ice within thousands of years.

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Source: Big History Project (Youtube Creative Commons)

Although not all scientists believe in the Snowball Earth, I found this theory to be a good example of what science is about. By looking at rocks underneath the ground and with the knowledge about how certain types of rocks form, geologists were able to hypothesize such an extreme event that occurred before humans walked the planet.

Adrian Li

Brains and games in 21st century – How do video games affect us?

There is a lot of debate regarding how video games influence our brains development and whether or not games are beneficial or damaging. Scientists have examined both sides and the question that needs to be answered is whether games are beneficial or they are transforming us into machines.

digital mindcredits: http://guardianlv.com/2013/08/researchers-develop-mind-control-using-the-internet-video/

Some studies show that prolonged exposure to video games has negative effect both on the body and the brain. Games decreases attention span, increase the risk of obesity and violent games decrease sensitivity towards aggression. The implications are troubling since decreased attention implies lower academic performance and obesity is a health risk factor. Furthermore it is shown that decreased sensitivity towards aggression not only makes us consider aggressive behavior acceptable but it also increases the chance that we will become aggressive.

aggressive gamers

credit to: http://yoursinglesourcefornews.com/ academics-debunk-theory-linking-violent-video-games-with-aggression/1379/

Another fact that must be considered is repetitive tasks in games. Because there are lots of games that become repetitive and have reward systems that encourage that behavior gamers are exposed to lose of creativity. Since repetitive tasks are better suited for a computer we could ask ourselves if our mind is encourage to become a basic processing unit.

However, there is another side of games which was investigated by researchers and the findings encourage people to become casual gamers. The benefits from games are as follow: better cooperation skills, adaptation to new challenges, fast reaction time and better attention to details.

brain-skills-games

credits: http://www.jklmgames.co.uk/how-games-can-train-the-brain

Besides the standard types of games we should also consider games that involve movement (e.g. some Nintendo Wii games) which are shown to motivate exercise. Those type of games should become encouraged in populations with increased risk of obesity, where the reward system should be tailor for the customers.

The tricky part of the games is the reward system which acts as a drug since it releases dopamine which is the hormone for excitement. Using this we can develop games that can stimulate people to learn and train. A study done on surgeons  showed it is possible to increase job performance via gaming. Here is a TED talk about games and how we can use them to construct a better world.

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Based on what we seen so far casual consumption of non-violent games have beneficial effects, however one must take extra care since crossing the line and becoming an addict can severely impact us.

Radu Nesiu

Newly discovered hormone can possibly change the future of weight loss?

Obesity is a leading health problem in Canada and many other countries throughout the world, with it becoming one of the leading causes of death worldwide. However, what if someone who is clinically obese can decrease their body fat simply by taking a pill? Modern prescription drugs for weight loss do exist; however, they aren’t very effective and can have messy side effects! 

Obesity, Author: Tony Alter, Source: Flickr Commons

Well, recent scientific discoveries may have found the perfect candidate to serve as a replacement for the current prescription drugs available for treating clinical obesity. Irisin, a hormone produced by skeletal muscle cells during exercise is capable of burning fat tissue reserves when introduced into circulation. Irisin achieves this by converting white fat cells, which are the fat cells used to store fat in the human body, into brown fat cells, which are fat cells responsible for burning fat to produce heat. 

An article published in Nature showed that increased irisin levels in humans and mice causes more brown fat cell development, which lead to an increase in energy usage in the form of burning existing fat tissues. This increase in energy consumption occurred in a controlled environment, without any changes in the mice’s amount of physical movement or food intake, which can lead to induced weight loss in obese individuals (Bostrom et al.). 

Tension quickly rose due to researchers speculating if irisin actually exists in the human body, with studies criticizing the methodologies that Bostrom et al. used to detect irisin within humans. However, a recent article published in Cell Metabolism  by Bruce Spiegelman showed definitive proof that irisin does exist in the human body. Instead of using more traditional methodologies commonly used to detect hormones in the human body; Bruce Spiegelman and his colleagues used  a new method involving mass spectrometry to accurately detect and quantify the amount of irisin in participating human subjects (Spiegelman et al.).

Isn’t that great then? Shouldn’t pharmaceutical companies quickly adapt the hormone irisin and start producing a weight loss pill? However, I think the issue of time restricts any advancements in the pharmaceutical industry in actually producing such a pill. Since irisin has only been discovered in mice recently, and confirmation of irisin in humans was only published in August 2015. 

Diet Pills

Diet Pills, Author: joaneQEscobe, Source: Flicker Commons

As well, I would like to bring up a similar weight loss drug that was invented in 1933 that also showed the same promise as irisin. DNP, or 1,3 dinitrophenol was shown to increase metabolism rates by converting chemical energy into heat. Though the mechanisms that they occur aren’t identical, the end result of increased body metabolism and body temperature is observed for both DNP and irisin. DNP quickly became a wonder drug that took North America by storm; even now, DNP can be purchased online as a diet pill. However, tragic deaths have been associated with usage of DNP as a weight loss treatment, with terrible consequences of DNP overdosing including fatal hyperthermia (extreme body heat).

I feel that with something as promising as irisin being capable of helping obese individuals loose weight, the pharmaceuticals, FDA, and researchers have to take responsibility and caution in the future. Making sure that if irisin does become a prescription drug to treat morbid obesity, the tragedies associated with DNP will not occur again in the 21st century. 

Here’s a video on Scishow explaining current weight loss pills :

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By: Yu Chieh (Brian) Cheng