All posts by sdhana3

An Evolutionary Perspective: Why Babies Cry

An article I read looked at a study published in Evolution, Medicine and Public Health, proposed an evolutionary reasoning as to why babies cry at night. The research proposed that babies consciously or unconsciously cry to their mother to prevent the birth of a new sibling that would ultimately end up mean competing for resources, and subsequent survival.  Apparently this sort of behavior does have an effect on mothers: nursing a child, especially at night, can stop women for resuming ovulation as essential for reproduction.  In this case, the baby is somehow employing a “survival of the fittest” mentality. Of course, many doctors do not agree, and argue that on the contrary, the nightly breast feeding may be cooperation as both baby and mother may benefit nutritionally and in terms of general health.

I personally jumped to Bonita’s presentation today about possible evolutionary theories behind anxiety, and I think the basis of attachment theory – the attachment a child has for his or her mother – causes anxiety may be the only basis of the child’s crying. It may be an anxiety of an inset fear of being separated from the mother, even if she is nearby that could cause crying fits, and as a child matures that anxiety is quelled with logic and understanding. Otherwise, looking at the theory proposed by the study, I do not see why a baby would EVER stop crying even after it matures into a child or older, at least until 15 or 16. Up to that point, it would still have a certain concern of competing for resources or attention and would not stop crying at night until it no longer was dependent on the mother for resources or survival. Of course, I am not an evolutionary biologist, so the theory might not be as ridiculous as it sounds to me, but I would personally need to see a LOT more research before I believed this one.

 

REFERENCES:

The Surprising Reason Babies Cry at Night. (n.d.). Care2. Retrieved April 24, 2014, from http://www.care2.com/greenliving/the-surprising-reason-babies-cry-at-night.htmlcry

Many Americans Skeptical of Evolution

Interestingly, I saw an article that actually ended up startling me than giving me the confidence I had hoped. According to a survey, most Americans are skeptic of evolution rather than having confidence in it as a concept. 31% of respondents said they were very confident that “life on earth, including human beings, evolved through a process of natural selection” whereas 42% said they were not at all confident. These results are surprising to me as I had largely hoped that Evolutionary medicine would be a part of undergraduate education. I had always known that evolution was a controversial topic, especially growing up in the South, but it surprised me just how much of a majority of Americans have no confidence at all. This makes it tough in the trajectory of Darwinian Medicine being implemented into medical practice, as the essential framework of the practice could contradict the beliefs of a large portion of Americans.

The article continues to highlight that these numbers are due to politics and religion, where once more science seems to be at odds with faith. Further, it also highlights that the implications of this rift are that many children will not be vaccinated and spread diseases because of the generalized distrust of certain scientific concepts. In the same survey, 15 % of Americans said they were not at all confident that childhood vaccines were safe and effective and 30% were not sure. 15% may not seem like a lot, but considering the number of Americans that amounts to it is a much larger number than I expected.

These sorts of differing views on evolutionary concepts may make it much tougher for evolutionary biologists and supporters of Darwinian Medicine to see their visions implemented in American education.

 

References:

Poll shows Americans not confident Big Bang, climate change or evolution is real. (n.d.). CBSNews. Retrieved April 24, 2014, from http://www.cbsnews.com/news/americans-big-bang-evolution-ap-poll/

A Step in the Right Direction For Evolutionary Medicine in Education

Considering it’s the last day of classes, I have been a little retrospective about our time this semester, and considering the importance of this course in general. I think it is great that this course is a part of Emory’s curriculum, and that many other universities are also adapting this kind of course in its biological education. What I found extremely exciting in terms of introducing Darwinian Medicine into undergraduate pre-medical education was how UCLA announced that since Fall 2013, they started Evolutionary Medicine as a minor for undergraduate students. This to me, is a great step forward for UCLA and a step towards the right direction for many other universities (such as ours) to follow in its footsteps.

Looking at the basic requirements, the minor would require 3 core classes:

1)      Evolution, Ecology and Biodiversity

2)      Intro to Ecology and Behavior

3)      Evolutionary Medicine

Apart from that, there would be 4 to 5 courses chosen from an incredibly diverse array of classes. These range from anthropology and physiological science to Community Health and Sociology. Other areas of elective courses include genetics, philosophy, sociology, and social welfare. The minor also has a research or internship requirement for an additional semester.

What, to me, sets this minor apart from the other minors that I have seen, is first a class directly geared towards medical practice and framework, and second the vast array of disciplines the minor covers. We as a class have discovered that evolutionary medicine includes a plethora of disciplines but to see that students will truly experience this interdisciplinary education is truly exciting. What other minor/major can allow you to choose from 17 different disciplines? Emory, take note!

References:

https://www.eeb.ucla.edu/images/EVMED_MINOR.pdf

UCLA introduces new evolutionary medicine minor. (n.d.). Daily Bruin. Retrieved April 24, 2014, from http://dailybruin.com/2013/09/30/ucla-introduces-new-evolutionary-medicine-minor/

Blue-eyed Humans have a Common Ancestor

A team at the University of Copenhagen were able to track down a genetic mutation that took place 6 to 10,000 years ago in the OCA2 gene that was able to create a “switch” which turned off the ability to produce brown eyes, by limiting the action of the gene to produce melanin in the iris, and dilute brown eyes to blue. Further, there is limited genetic and phenotypic variation in the eyes of blue – eyed people. For example, variation in melanin causes the differences in brown and green eye color, but blue-eyed individuals exhibit very little variation in the amount of melanin in their eyes, and also have inherited the same mutation at the exact same locus on their DNA, lending to the theory that all blue-eyed individuals have a common ancestor and the mutation is found to be passed maternally. Mitochondrial DNA was examined from diverse countries such as Jordan, Denmark, and Turkey (1).

However, the question most people, at least when it comes to our class, have is what does this mean in the context of evolution and natural selection? The answer: depends on who you ask. Some articles (1) claim that the mutation of brown eyes is neither a positive or negative mutation. Just as other mutations (hair color, baldness, etc.) do not increase or decrease a human’s chance of survival; hence nature has attempted to merely switch up the genome in this cocktail theory. It is interesting from a student perspective, to remind ourselves that sometimes nature does not necessarily directly work in favor of increased fitness.

On the other hand, others assert (2) that the mutation arose through the mechanism of sex selection, which we in our previous class understood as “ornamental demonstration” where in an area of increased competition for reproduction, males and females will choose their mates due to one peculiarity or phenotypic variance (such as with seen in the demonstration of male peacocks) in an effort to diversify genes and subsequently increase fitness.

Though, I agree much additional research is needed regarding the mechanism and the common – ancestor theory itself, it is an interesting topic, and increased studies across multiple population – types may be helpful.

Evolution Under Pressure

(from article - see link)
(from Wired Science)

Interestingly enough, this article entitled, Does Evolution Evolve Under Pressure?, in Wired Science magazine discusses a slight departure in the topics discussed Tuesday in class regarding understanding the concept of evolution and natural selection.  According to the article, Susan Rosenberg theorized that bacteria can self- mutate in the sense that they can, under pressure, induce increased rates of mutations in the hopes of finding an “escape route”.  This sort of theory straddles the lines between Darwinian and Lamarckian realms of thought: the grey area between self-mutation and trial and error. Some may argue that this is a form of artificial selection because the general course of evolution is not occurring – it is being tampered with by the organism itself. This then also begs the question that if this theory holds to be true, then what does this indicate for certain realms of study such as antibiotic resistance and the evolution of cancer? If scientists or researchers could somehow try to control for stressors that induce mutations in the first place, could that somehow impede the process of evolving antibiotic resistance and further change the practice of medicine and oncology? Ideally, if this theory holds to be true and applicable, evolution could not only be important to understand in medical education as an important framework and understanding why, but now could have direct implications to preventative medicine in terms of determining how. Doctors could advise against certain stressors that induce certain mutations in some bacterial infections or certain tumors (that can also develop antibiotic resistance).  The article also goes into further detail describing studies that were able to create conditions that induce organisms to mutate at higher frequencies. This theory largely remains controversial, and it would be interesting to look into how critics explain a reasoning behind the successes of these mentioned experiments. A link is provided to the article below: http://www.wired.com/wiredscience/2014/01/evolution-evolves-under-pressure/