AP Biology class blog for discussing current research in Biology

Author: nyrsoccer

Epigenetics – Exercise Runs In The Family

It is common fact that people who exercise frequently are more likely to live a longer healthier life, but now new studies show that if a person exercises it can also result in a better life for his or her children and even grandchildren. Before the study of epigenetics people always thought the genome they are born with it the genome they are stuck with. However new science has shown exercise not only changes the outward appearance of our muscles and overall physical health, but also changes our DNA.

Exercise, astonishingly, can effect gene shape, function, and turn them on and off. Scientists now know that genes can actually be quieted or amplified through exercise because biochemical signals are sent out every time a person exercises. This is where epigenetics comes in. Epigenetics doesn’t simply change the gene all together, but instead works its magic on the outside of each gene through a process called methylation. A cluster of atoms surround the genes either denying or amplifying biochemical signals. Scientists believe that even one day of exercise can change methylation patterns.


One study done by scientists at the Karolinska Institute in Stockholm put the theory of exercise and epigenetic’s to the test. They studied 23 young and healthy men and women. They asked all the participants to work out half of their lower body for three months. This way each member of the study was his or her own control and experimental group. Obviously, after the three months each members leg that was worked out was stronger than the other, but what was much more intriguing was the results at the molecular level. The scientists found significant methylation changes in the cells of the leg that were worked out, averaging 5,000 sights on the genome where there was a new methylation pattern. Many of these methylation patterns were changed on enhancers, which are important for amplifying gene expression. The genes that were most affected were those that play a role in energy metabolism, insulin response, and inflammation within muscles. Exercise, along with many other healthy lifestyle tasks, has shown to cause changes in a persons epigenome. Changes that make a person healthier, but perhaps even more significantly, can make his or her children and grandchildren healthier.


Trust Your Eyes?

How do illusions deceive people into seeing false perceptions of what is actually in front of them? Illusions are caused from a misunderstanding between eyes and the brain. All illusions start with the eyes. The light that bounces off an object enters the cornea of the eye. The cornea refracts the light through the pupil. The light rays then go through the lens towards the retina where the nerve cells are present. The cells, commonly called rods or cones, which are the two types of cells that  send the light through the optic nerve for the brain to interpret. Illusions are set up in a particular way with patterns, images or colors that trick the brain.

Illusions sometimes occur due to familiarity of the situation we are falsely perceiving. The whole process of interpreting information takes fractions of a second, so often times the brain quickly notices a familiar situation and is hard wired into coming to a conclusion. The link below displays a picture providing an example of this phenomena. The second picture consists of what seems to be simply a nature photo, but with a closer look actually shows the outline of a women’s face. Naturally the brain quickly perceives just trees becasue it is the “normal” understanding of the photo.

Another type of illusion, called a physiological illusion, occurs from a certain type of light, color, and position. This type of illusion occurs when the stimuli that are sent to the brain are so intensive or repetitive that it causes some sort of jam that creates a misperception. The picture below seems to be moving side to side. The reason this illusion works is becasue the repetition that the eyes can’t fully digest and an over stimulation occurs.



Sometimes simply context can confuse the mind. The illusion below shows two groups of circles. The middle ones on both sides are surprisingly the same size. It is extremely shocking because the one on the left looks much bigger than the one on the right. This happens becasue the brain groups each part of the image separately and compares those circles. The circle on the left is big compared to the others while the one on the right is smaller than the others. This shows how the brain analyses some situations. The brain simply compares each circle to the other and gives it a general big or small association.


Essentially illusions come from the false information and trickery our eyes send to the brain. Our eyes and brain work to process information in fractions of a second. Because of this optimization and simplicity is key. Rather than fully grasping all of the information many comparisons and quick conclusions can be made. The brain is forced to take shortcuts with comparisons such as light and dark, big and small, and shape to quickly adapt and react to what the eyes see.

Invasive Rabbitfish

A team of researchers, lead by Dr. Adriana Vergés and Dr. Fiona Tomas, has recently discovered a species of tropical fish that “poses a major threat to the entire Mediterranean basin.” The species, called a rabbitfish has greatly harmed the algal forests in the Mediterranean Sea, primarily the eastern portion. The rabbitfish arrived in the waters of the Mediterranean through the Suez Canal. The rabbitfish are not indigenous to the Mediterranean waters, which makes them so dangerous to the ecosystem. This phenomenon has also been observed in lionfish, snakehead fish, and other organisms that are not indigenous to the location that they are harming. The rabbitfish have been eating seaweed and other ocean plants, which provide shelter and food for other species.


The scientists conducted their study by examining 1000 kilometers of coastline in the eastern Mediterranean specifically Turkey and Greece. Both places two separate species of rabbitfish have come to inhabit. The two areas focused upon were warm and cold regions. In the warmer regions the rabbitfish were present while in the colder regions they were not. The warmer regions filled with rabbitfish had a much lower abundance of seaweeds, and were mostly barren rocky bottoms. On the other hand the colder climates had a thriving ecosystem. There was a 60% reduction in algae and invertebrates and 40% reduction in overall species present in the warm rabbitfish filled environment. After filming rabbitfish as well as indigenous species scientists realized that rabbitfish didn’t actually eat more algae than other fish. However, the distinction was that rabbitfish ate both young and adult algae while indigenous species only ate adults. Eating the young and growing algae before it has a chance for reproduction quickly reduces the overall population.

This topic interested me not only because of my love for marine biology, but also because marine sustainability is extremely important to humans. Without oceans there would be no human life on Earth. The abundance of water is what separates a lush green planet like Earth from the rest of the planets in our solar system. In addition the marine ecosystems are very important, and there have become more and more invasive species due to changes in the environment. Fish such as the rabbitfish threaten whole ecosystems as well as hundreds or even thousands of species that rely on those ecosystems.

Should humans attempt to stop this infestation of rabbitfish? If so, what should be done?



Powered by WordPress & Theme by Anders Norén

Skip to toolbar