BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: diversity

Unnatural Selection: The Future of The Future?

By

On March 20, 2022

In Student Post

Imagine it’s Saturday night, you are snowed in until the morning and you need a way to pass the time. Like many people, you resort to Netflix. Upon browsing through the vast selection of horror, comedy, and romantic films, you decide you are in the mood for a documentary. Scrolling through the options, you stop at a title that grabs your attention: Unnatural Selection.

Since you are an AP Biology student, you immediately connect the words “Natural Selection” to the work of Charles Darwin, the study of genetics, and most importantly: evolution. In brief, natural selection is the survival and reproduction of the fittest, the idea that organisms with traits better suited to living in a specific environment will survive to reproduce offspring with similar traits. Those with unfavorable traits may not be able to reproduce, and therefore those traits are no longer passed down through that species. Natural selection is a mechanism for genetic diversity in evolution, and it is how species adapt to certain environments over many generations.

If genetic diversity enables natural selection, then what enables unnatural selection? Well, If natural selection eradicates unfavorable traits naturally, then unnatural selection essentially eradicates unfavorable traits or promotes favorable traits artificially.

The Netflix docuseries “Unnatural Selection” focuses on the emergence of a new gene-editing technology named CRISPR (an acronym for “Clustered regularly interspaced short palindromic repeats”). CRISPR is a revolutionary new method of DNA editing, which could help cure both patients with genetic diseases and patients who are at risk of inheriting unwanted genetic diseases. The two pioneers of this technology, Emmanuelle Charpentier and Jennifer Doudna, recently won Nobel Prizes in Chemistry for their work on CRISPR.

CRISPR illustration gif animation 1

Animation of CRISPR using guide RNA to identify where to cut the DNA, and cutting the DNA using the Cas9 enzyme

CRISPR works with the Cas9 enzyme to locate and cut a specific segment of DNA. Scientists first identify the sequence of the human genome, and locates a specific region that needs to be altered. Using that sequence, they design a guide RNA strand that will help the Cas9 enzyme, otherwise known as the “molecular scissors” to locate the specific gene, and then make precision cuts. With the affected region removed, scientists can now insert a correct sequence in its place.

Using the bacterial quirk that is CRISPR, scientists have essentially given anyone with a micropipette and an internet connection the power to manipulate the genetic code of any living thing.

Megan Molteni / WIRED

CRISPR is just the beginning of gene editing, introducing a new field of potential gene editing research and applications. But with great power comes great responsibility — and great controversy. Aside from the obvious concerns, people speculating the safety, research, and trials of this new treatment, CRISPR headlines are dominated by a hefty ethical dilemma. On one hand, treating a patient for sickle cell anemia will rid them of pain and suffering, and allows their offspring to enjoy a normal life as well. However, by eliminating the passing down of this trait, sickle cell anemia is slowly eliminated from the human gene pool. Rather than natural selection choosing the path of human evolution — we are. We are selecting which traits we deem “abnormal” and are removing them scientifically. Although CRISPR treatment is intended to help people enjoy normal lives and have equally as happy children, putting evolution into the hands of those evolving can result in more drastic effects in the future.

For our generation, CRISPR seems like a magical cure for genetic diseases. But for future generations, CRISPR could very well be seen as the source of many problems such as overpopulation, low genetic diversity, and future alterations such as “designer babies.” Humans have reached the point where we are capable of our future. Is CRISPR going to solve all of our problems, or put an end to the diverse human race as we know it? Comment how you feel down in the comments.

 

Is Racial Bias Ruining Science?

By

On March 10, 2021

In Student Post

In this video posted by Wonder Collective on Youtube, Dr.Esteban Bruchard gives a general overview of how racial biases have been implemented into medicine and general science. Primarily, Dr.Esteban Bruchard shed light on the exclusion of minorities from clinical research. By doing this the scientific conclusions had to be generalized to other groups who haven’t been included in the research. Specifically, a graphic that was shown in the video, showed that a drastic 81% of the participants of a “Recent genome study” were European.  Other races making up only 19% of the participants. The underrepresentation of other races will cause an inability to properly assess certain situations regarding other races. An example of this, as touched upon in the video, was how a difference in gene frequency in Blacks caused many African-Americans to be misdiagnosed with an enlarged heart.

Black patient getting attended to by a doctor

This isn’t the only instance of racial biases affecting science and medicine. In an article by Mathieu Rees, the topic of racism in healthcare is further discussed. Rees, dives into how certain aspects such as pregnancy, emergency care, pain treatment, etc. One thing that Rees highlights in his summary is that these racial biases can lead to inaccurate diagnoses. Rees also uses some statistics to show the racial disparities in healthcare. A specific statistic that I found alarming was a study that was conducted with white medical students in 2016. In this study, “73% held at least one false belief about the biological differences between races”. Examples of some of their beliefs were “Black people having thicker skin, less sensitive nerve endings, or stronger immune systems.” Not only are these biases alarming because of the obvious racial assumptions, but it is also so problematic because the people with these preconceived notions are those who will potentially be leading the healthcare of the future.

Going forward there are many steps that need to be taken to prevent the prevalence of racial biases in healthcare and sciences. One big step that can be taken is the involvement of more POC in the science world. Not only in hospitals as leading figures like doctors and physicians, but also as participants in things like clinical trials, advanced studies, etc. Also, the acknowledgment of various “social factors that affect health outcomes“. Finally, addressing these biases head on is one of the best ways to avoid them from being prominent in the line of work and in the development of science.

Diet Tip #1: Hang Out with Skinny People and Go on a Low Calorie Diet

By

On November 16, 2014

In Student Post

labrat

Microbiomes are incredibly vast and mysterious; we don’t quite know how they work. However, with a few experiments, we have come to a few conclusions.

1) Microbiomes determine your weight.

Scientists extracted bacteria from the intenstines of human twins, one lean and one larger. The injected these microbiomes into twin mice. The mouse who received the large twin’s microbiome gained fat and the mouse who received the lean twin’s microbiome remained small.

2) Fat microbiomes can be influenced by a skinny microbiome.

A fat mouse placed in a cage of skinny mice lost weight.*

3) Skinny microbiomes cannot be changed.

A skinny mouse placed in a cage of fat mice remained skinny.*

4) With the correct diet, you can become skinny.

Fat mice eating healthy food made them skinny but when they ate junk food, they stayed fat. A different group of scientists replicated this experiment with overweight humans and a low calorie diet. Their microbiotic diversity was low and increased significantly, leading to weight loss.

5) Diet does not affect skinny people.

Regardless of which diet the skinny mice ate, they stayed skinny. A different group of scientists replicated this experiment with skinny people and a low calorie diet. Their microbiotic diversity was already high and did not change much.

*read the full study here

Why?

Fat microbiomes tend to be more efficient at extracting nutrients from food and storing the excess, so whenever someone with an efficient microbiome eats, he/she stores a lot of the nutrients. Skinny microbiomes, on the other hand, are not as efficient at extracting nutrients so there is less energy to store after a meal. Going on a low calorie diet if you want to lose weight could solve the problem because whatever can be extracted from the food will be used for day to day functions. Considering that skinny people already are not extremely efficient at extracting nutrients, a low calorie diet will not necessarily cause any significant changes.

This source performed a study (humans) where they discovered that obese people typically have lower genetic diversity than lean people. Obese people who went on a low calorie diet had a higher genetic diversity at the end of the experiment than those who did not go on a low calorie diet, and obese people who continued to have a low genetic diversity gained significantly more weight over nine years. Lean people who went on a low calorie diet did not have a significant increase in microbiotic diversity compared to lean people who did not go on that diet. However, this correlation does not imply causation because some obese people have a high genetic diversity. Scientists believe that a low genetic diversity is linked to metabolic disorders, which could cause obesity, but that obesity in and of itself is not always caused by low genetic diversity.

Whenever you touch, breathe, or eat something, bacteria is entering your body and interacting with the native bacteria. So, when fat mice interact with skinny mice, it’s possible that the fat mice pick up diverse bacteria from skinny mice, contributing to their increase in microbiotic diversity, and when skinny mice interact with fat mice, they can’t lose genetic diversity but also have nothing really to gain from mice with low genetic diversity.

Conclusion: If you have a metabolic disorder, it could be beneficial to surround yourself with skinny people and eat low calorie foods because you’re more likely to absorb diverse types of bacteria while also storing less energy from food.

Echinacea’s Habitat Decline

By

On February 28, 2014

In Student Post

The plant that is commonly used to treat flu and cold symptoms, Echinacea, is beginning to suffer from a disappearing habitat. A flowering plant part of the daisy family, Echinacea grows in central and North America in mostly dry, wooded areas. As one of the “top five” herbal remedies sold in retail stores, the coneflower is regarded as an American staple to relieve suffers’ of the cold and flu. However, their habitat is in decline from human activities, bees, and deadly aphids

EchinaceaPurpureaMaxima1a.UME          Certain human activities have caused wildlands to shrink and splintered the landscape. As one of the most endangered habitats in the world, tailgrass prairie is throughly studied by scientists in order to track how Echinacea reacting to its changing environment and they are also working to save these prairie patches.

Bees have been known by scientists to pollinate the coneflower plant, Dr. Wagenius says “A bee might have been able to fly across a hundred mile expanse of coneflowers. Could it still do that today? No way.” Pollination for these plants is not at all where it should be, as bees can only pollinate these plants up to short distances.

Coneflower plants are now becoming genetically related in the prairies. If a bee brings pollen to these different plant siblings, the plant may reject the pollen. Therefore, there are no new seeds and populations decrease. A new danger to the coneflower is aphids; they devour prairies of Echinacea. As well, scientists urge prairie farmers to set fire to habitats (since they are necessary to these ecosystems). By inducing the plant to flower, new genetic diversity may be reached.

Coral Reef Bleaching Puts Fish’s Ability to “Just Keep Swimming” in Danger

By

On October 7, 2013

In Student Post

Coral reefs are vital sources of life for many sea creatures. The diversity of the underwater ecosystems surrounding coral reefs are, unfortunately, being put in danger because of coral bleaching. According to the National Ocean Service, coral bleaching is due in part by a process that is the result of damaged chloroplasts in coral cells which produce “toxic, highly reactive oxygen molecules during photosynthesis.” The main cause of this issue, is temperature; the coral respond to the drastic changes in temperature, whether they be hot or cold, by releasing the symbiotic algae that dwell in their tissues, which result in the coral taking on a white, “bleached” color.

Found on Flickr, Licensed under Creative Commons Licensing

Coral bleaching has both negative internal and external effects. Internally, the coral’s ecosystems are placed at risk because they “rely on live coral for food, shelter, or recruitment habitat.” This is a major issue, as we have the potential to lose certain, diverse, species that live off of and around coral reefs, which, in turn, could negatively influence the food chain. The external effect is that there will not be tourism revenue brought in from people who scuba dive to the coral reefs affected by bleaching. This is due to the fact that they will no longer be aesthetically appealing. Thus, leading to a negative economic state in tourism hot spots.

Unfortunately, the temperature of the Earth is out of human control, so there is little we can do to prevent coral bleaching, but we can use the rapidity of the bleaching as a marker to gauge the temperature of the world.

Archives

Powered by WordPress & Theme by Anders Norén

Skip to toolbar