Step 1: Read
https://learn.genetics.utah.edu/content/epigenetics/rats/
Step 2: Read Sources
https://learn.genetics.utah.edu/content/epigenetics/twins/
https://learn.genetics.utah.edu/content/epigenetics/nutrition/
https://learn.genetics.utah.edu/content/epigenetics/brain/
https://learn.genetics.utah.edu/content/epigenetics/brain/
Answer Questions- word count does not matter
1. Various environmental factors, such as diet/nutrition, parental care, and social interaction have been shown to influence the epigenome and ultimately behavior in many different species, including insects, rodents, and humans. Choose a specific behavior that probably evolved biologically but varies in different people. Suggest at least one environmental factor that could account for variation in this behavior. Is there evidence to support an epigenetic link to variations in this behavior?
2. Gene by environment interactions (or gene x environment interactions) are ways in which specific genotypes, after exposure to different environmental factors, show variation in the phenotype. For example, different alleles of the serotonin transporter are associated with individual stress susceptibility and risk of developing mood-related disorders (e.g., depression, anxiety). Why do you think the environment can modulate genes associated with brain structure and function? Comment on whether these interactions evolved to enhance our survival.
Give a brief 75 word response to the two examples below
Example 1
1. Childhood neglect causes rats to have more anxiety. High-nurturing mothers raise high-nurturing pups, and low-nurturing mothers raise low-nurturing pups because of her behavior, not her dna. Low nurtured rats are less likely to lower their guard in a high danger environment saving them from getting eaten by a predator but in a low danger environment like how humans live, low nurtured rats have a higher risk of diabetes and heart disease (Lick Your Rats, n.d.). This helps the species survive when there is scarce food and there is a lot of predators. Mothers in dangerous environment pass down the epigenetic pattern that kept them alive.
2. Differences in protein synthesis are found in depressed patients as well as patients with Alzheimer’s. Higher methylation in the brain is associated in people who were abused and committed suicide vs different causes of death like a car accident. Genes and brain signals are factors that can change how methylation affects an individual. Another factor is childhood abuse. People who were abused and committed suicide share a certain methylation not found in people who were not abused and committed suicide (Epigenetics & the human brain n.d.).
The brain alteration in methylation could be to protect the brain from further abuse and extend our survival, this alteration also appears in rats who were neglected as pups (Lick Your Rats, n.d.). The suicide could be a byproduct like how different alleles of serotonin transporters are associated with individuals with stress susceptibility and a higher risk of developing depression and other mood disorders.
Example 2
- The behavior I chose to focus on is severe anxiety. I used to be able to just get on any roller coaster in my teens without having to think about it or hesitate. Now I am in my early twenties, and I am terrified of thinking about the feeling of getting on a roller coaster. The last time I went on a roller coaster was 2 years ago and I was crying before it even took off. My mother struggles with severe anxiety and panic attacks, so, unfortunately, she passed it on to me. and her mom passed it on to her. As I grew up, I realized that I was aware of my anxiety, and I had to learn to live with it. In the article, “What is Severe Anxiety” it states, “Severe anxiety occurs when the body’s natural responses to anticipated stress exceed healthy levels. The symptoms—a racing heart, changes in breathing, and headaches—can hinder your ability to carry out day-to-day tasks. The mind and body naturally perceive and react to potential threats automatically, to stay safe. This is often helpful and means your body is working the way it should. Anxiety is a way of preparing for future stress or possible negative experiences. Long-term or recurrent severe anxiety can be a sign of an anxiety disorder. Left untreated, it can lead to chronic health problems, including heart disease” (Porrey, 2023).
- The brain is particularly responsive to experiences and environments during early development. External experiences spark signals between neurons, which respond by producing proteins. These gene regulatory proteins head to the nucleus of the neural cell, where they either attract or repel enzymes that can attach them to the genes. Positive experiences, such as exposure to rich learning opportunities, and negative influences, such as malnutrition or environmental toxins, can change the chemistry that encodes genes in brain cells — a change that can be temporary or permanent. This process is called epigenetic modification (Harvard University, 2015) In conclusion, our brain naturally develops a survival mode to keep us safe, therefore I do believe that these interactions have evolved to enhance our survival instincts.
