Author Archives: karnvir dhillon

The Escalator to Extinction

On those rare summer days when the temperature is climbing to nearly forty degrees celsius, you have probably dreamed of climbing into a freezer. Well, this desperation to escape the heat is not unique to us. As humanity drives the temperature up through global warming, many tropical species are in desperate need of a good fan. But with a lack of appliances in the tropical wilderness, they are starting to migrate up mountains to escape the heat. However, this one way escalator ride up the mountain may be leading to extinction. 

Source: Pixabay.com

Dr. Freeman’s Research: 

Dr. Benjamin Freeman, an evolutionary ecologist at the University of British Columbia, aims to understand how global warming is impacting where montane (mountain-dwelling) species live. His recent study highlights how climate change is causing species to shift upward, which can lead to the extinction of species living higher up on mountains. This phenomenon is known as the “escalator to extinction” which is explained by the video below: 

To make these conclusions, Dr. Freeman examined datasets from various studies that measured elevational shifts associated with global warming over the last 100 years. Based on his findings, the escalator to extinction is around the corner for tropical montane species. 

Effects of the escalator to extinction: 

This phenomenon can have various effects on montane species and our society as discussed in the following podcast.

Thank you to freesound.org for providing the sound effects used in our podcast (plasterbrain, InspectorJ)

In the podcast, Dr. Freeman mentions that less available land at higher altitudes of a mountain are threatening montane species. 

Why is this the case?

Less available land at higher altitudes often means less resources for organisms to use. Thus, as species continue to shift upslope to evade the heat, there will be increased competition within species populations and between different species. This competition for resources such as food and habitat will likely result in the strongest species surviving, and lead to extirpations (loss of species populations) of weaker species. Some examples of extirpations caused by the escalator to extinction are populations of the White-eared Solitaire and Fulvous-breasted Flatbill as found by a previous study by Dr. Freeman.

Furthermore, temperature-dependent (requiring specific temperature to survive) crop diseases such as Agrobacterium tumefaciens shifting upslope can greatly affect human populations living in mountains. For example, introducing new crop diseases can lead to lower crop yields. Thus, human communities in mountains can potentially face unexpected food shortages, and be forced to find different sources of food. 

How can we prevent this? 

If we cannot stop global warming, we must guide animals to higher elevations to save them from extinction. Many species go extinct because they are restricted from higher elevations due to human agricultural activities that divide up lands. One possible way to facilitate their upward migration is through the development of corridors that give species a path to higher elevations. In addition, we can plant trees at higher altitudes to provide new habitats for these displaced organisms.

Once grown, these newly planted trees will provide accessible habitats for species and as a result, potentially reduce extirpation events. 

Source: commons.wikimedia.org/

But really, the best thing we can do is raise awareness of this critical issue.

-Karnvir Dhillon, Declan O’Driscoll, Samantha Nalliah, Matthew Lim 

 

A Potential New Class of Insect Repellents Using Catnip!

Although catnip is often used as a special treat for cats due to its euphoric and hallucinogenic effects, it has quietly been known as a powerful insect repellant. This strong reaction towards insects has led to scientists considering catnip as a potential replacement for currently available insect repellents.

However, up until now, it was not understood how exactly catnip repels insects. A recent study performed by Dr. Nadia Melo and her research team provides the necessary context to show how exactly one of the main chemicals in catnip, nepetalactone, can be used to create the next class of insect repellents!

Insect repellents are used to fend off insects such as this mosquito, which can spread disease through its bite.

Source: Unsplash.com/ekamelev

What’s wrong with current insect repellents?

DEET and permethrin are currently the two most commonly used chemicals in insect repellents. These chemicals get the job done, but they do have their downsides.

Firstly, certain mosquito species are developing resistance (ability to withstand effects) to insect repellents containing these chemicals according to a study performed by Dr. Deletre’s research team. This is very concerning as it is important for insect repellents to be effective at stopping mosquitoes because they are prominent spreaders of diseases such as malaria.

This short video by MalariaGEN does a great job explaining what resistance is in further detail and talks about how insecticide resistance occurs.

Video Source: MalariaGEN | Youtube

Furthermore, insect repellents with DEET and permethrin have their dangers, as they can potentially have toxic effects in adults based on reactions that some people have had

Keeping these reasons in mind, it is clear that there is a growing need for a better insect repellent than the current insect repellents on the market.

This is where catnip comes into play.

What makes catnip a good insect repellent?

Catnip contains a chemical called nepetalactone that is able to repel certain insects including mosquitoes. Research has shown that nepetalactone has similar effectiveness to DEET, indicating that it can be a good replacement for current insect repellents. Furthermore, nepetalactone has shown that it is non-toxic to humans based on the many interactions that humans have had with catnip.

How it works:

Dr. Nadia Melo and her research team were able to determine exactly how nepetalactone causes a strong reaction in insects. They found that nepetalactone was able to activate a pain receptor called TRPA1 in insects, which caused a strong irritating response in the insect’s body. In other words, nepetalactone turned on a switch in the insects that resulted in them experiencing pain. 

Scientists have stated that the way this chemical irritates insects is more complicated than the way that DEET and permethrin repel insects. Thus, they have suggested that mosquitos and other insects are less likely to obtain resistance to nepetalactone. 

Future of Nepetalactone:

The doors are now open for a new generation of insect repellents based on catnip. 

The use of nepetalactone to make new insect repellents can potentially replace current insect repellents containing DEET such as the one shown here.

Source: flickr.com/skiarc

Nevertheless, there is still work to do. Future studies are now looking into whether nepetalactone can be modified to trigger an even stronger reaction in insects. Furthermore, they are looking into exactly which species of insects that this insect repellent will work for.

-Karnvir Dhillon

 

 

A Promising Treatment in the Fight Against Microplastics

Over the past few years, there has been a global effort by scientists to develop a treatment that is able to limit the pollution of microplastics into marine environments. Fortunately, Marthe Kiendrebeogo and her research team may have found a solution. They discovered that they were able to effectively break down a sample of microplastics through anodic oxidation. 

Now you may ask, what are microplastics?

Microplastics are pieces of plastic less than 5 mm in length. The three main sources of microplastics are the breakdown of larger plastics, cosmetics and laundry washes. All three of these sources have contaminated marine environments all over the Earth. To put this into perspective, a recent study has suggested that there are approximately 12-125 trillion microplastics floating in the oceans today. 

A collection of mainly plastic material that washed ashore. Plastics, such as a water bottle, can be degraded and become a source of microplastics.

Credit: unsplash.com/john_cameron

The Effect of Microplastics on Life:

The buildup of microplastics in aquatic life through ingestion can lead to toxic (harmful) effects. These effects were studied by a different research team led by Dr. Kogel where they found the toxic effects included infertility, decreased growth rate, shorter lifespans, and internal damage. Furthermore, microplastics are known to travel up the food chain and eventually reach humans. There is currently a lack of information regarding the effects of microplastics in humans, but several studies are in progress.

YouTube Preview ImageFor those interested, Drs. Sarah Dudas and Peter Ross show the presence of microplastics in aquatic life in this video.

And now to the study:

With the background information out of the way, I’m going to explain how Marthe Kiendrebeogo and her team created a potential solution to tackle the rising issue of microplastics.

This research team found that the process of anodic oxidation breaks down microplastics efficiently. Anodic oxidation involves a lot of chemistry, but the main thing to know is that it creates hydroxyl radicals (OH-) without adding extra chemicals into the water. These hydroxyl radicals are very good at attacking and breaking down microplastics. The full mechanism is in the article for those interested. This study found that with their proposed mechanism, 58 ± 21% of microplastics broke down in 1 hour which reached approximately 80% in 3 hours. 

I think that the most significant result in this study is that 58 ± 21% of polystyrene was degraded in 1 hour because an hour is close to the time of a normal laundry cycle. A laundry cycle puts a lot of stress on clothing fabrics which leads to the release of microplastics. In fact, a recent study has estimated that 35% of microplastics in oceans can be contributed to laundry. Thus, this mechanism would be very effective at decreasing the amount of microplastic production if it was implemented into laundry machines.

The addition of this treatment into laundry machines can limit the number of microplastics released at the initial source.

Credit: unsplash.com/scottsweb

Based on the results of this study, the future of treatments for microplastics sounds more promising. Nevertheless, there still is a lot of work to be done. The next step for this promising treatment would be to test the effectiveness of the proposed mechanism on samples consisting of other microplastics. 

-Karnvir Dhillon