Genetics and Gene Development

LO 3.1.A – Behavioral Genetics and DNA

  1. What is the difference between genes and chromosomes?

    • Genes are specific sequences of DNA that encode instructions to produce proteins or RNA. Chromosomes are structures made up of tightly coiled DNA and proteins, containing many genes.

  2. Explain the role of non-coding DNA in the genome.

    • Non-coding DNA regulates gene expression, maintains chromosome structure, produces non-coding RNAs (like microRNAs), and plays a role in evolutionary adaptation. Although it doesn't code for proteins, it is crucial for the proper functioning of genes and cellular processes. Regulating gene expression, maintaining genome structure, and facilitating important cellular processes by acting as control switches that determine when and where genes are turned on or off

  3. How do genome-wide association studies (GWAS) help us understand genetic influences on behavior?

    • Genome:  The full set of genes in each cell of an organism (with the exception of sperm and egg cells), together with noncoding DNA located outside the genes

    • GWAS identify genetic variations across individuals in a population and correlate them with specific traits or behaviors. This helps researchers find potential genetic risk factors or markers associated with complex behaviors or diseases.

  4. Define genetic markers and their relevance in genetic research.

    • Genetic markers are specific DNA sequences that vary among individuals and can be associated with certain traits or diseases. They help researchers track the inheritance of genes and study genetic predispositions.

LO 3.1.B – Epigenetics

  1. What is epigenetics and how does it influence the expression of genes related to behavior?

    • Epigenetics refers to changes in gene expression caused by mechanisms other than changes in the DNA sequence itself, such as DNA methylation or histone modification. These changes can be influenced by environmental factors and can affect behavior, potentially being passed down across generations.

  2. Provide an example of how environmental factors might alter gene expression through epigenetics.

    • Environmental factors such as stress, diet, and toxins can alter epigenetic marks on DNA, potentially leading to changes in gene expression. For example, chronic stress can lead to methylation of genes that regulate stress responses, affecting how an individual responds to future stressors.

LO 3.2.A – Natural Selection and Evolution

  1. How does natural selection lead to changes in gene frequencies within a population?

    • Natural selection favors individuals with advantageous traits that increase their chances of survival and reproduction. Over time, these traits become more common in the population, leading to changes in gene frequencies.

  2. Define evolutionary psychology and provide an example of how it explains human behavior.

    • Evolutionary psychology studies how human behavior is influenced by evolutionary pressures. For example, human preferences for certain foods may have evolved due to their nutritional value and the survival benefits they offered in ancestral environments.

  3. What are mental modules in the context of evolutionary psychology?

    • Mental modules are specialized, evolved mental mechanisms that are designed to solve specific adaptive problems. These modules helped our ancestors survive and reproduce in their environments.

    • Mental Modules include ​​inborn reflexes, such as an attraction to novelty, a motive to explore and manipulate objects, an impulse to play, and the capacity for certain basic cognitive skills, including a rudimentary understanding of numbers

LO 3.2.B – Innate Human Characteristics

  1. What are some examples of innate human characteristics, and how do they contribute to survival and reproduction?

  • Examples include infant reflexes, an interest in novelty, a desire to explore and manipulate objects, an impulse to play and fool around, and basic cognitive abilities. These characteristics contribute to survival by helping humans navigate social interactions, communicate, and respond to threats.

LO 3.3.A, B – Sociobiology and Sexual Strategies

  1. How do males and females differ in their sexual strategies from a sociobiological perspective?

  • Males often adopt an approach focused on quantity, seeking to maximize reproductive success through mating with multiple partners. Females tend to invest more in each offspring and therefore may be more selective in choosing mates based on traits that signal genetic quality or the ability to provide resources.

  • Males generally want sex more often than females do; males are often fickle and promiscuous, whereas females are usually devoted and faithful; males are drawn to sexual novelty, whereas females want stability and security; males are relatively undiscriminating in their choice of sexual partners, whereas females are cautious and choosy; and males are competitive and concerned about dominance, whereas females are less so.

  1. What are some common challenges to the evolutionary view of human sexual strategies?

  • Critics argue that human sexual behavior is influenced by social, cultural, and environmental factors rather than purely evolutionary forces. Additionally, human behavior is more complex than the binary distinction between male and female strategies, with a wide range of individual variations.

  • Sociobiologists contend that evolution has bred into each of us a tendency to act in ways that maximize our chances of passing on our genes and to help our close biological relatives (with whom we share many genes) do the same.

  • Stereotypes versus actual behavior, What people say versus what they do, Convenience versus representative samples, The Pleistocene period is over(no need to place so much emphasis on that)

LO 3.4.A – Heritability of Behavior

  1. What does the concept of heritability refer to in the context of behavioral genetics?

  • Heritability refers to the proportion of variation in a trait within a population that is attributable to genetic differences. It does not apply to individuals but rather to the population level.

  • How differences in genes account for differences in traits 

  • Heritability: An estimate of the proportion of the total variance in a trait that is attributable to genetic variation within a group

  1. What are some key points to keep in mind when discussing heritability and genetic contributions to behavior?

  • Heritability is context-dependent and varies across different populations and environments. It is also important to remember that high heritability does not mean behavior is determined entirely by genes; environmental factors play a significant role.

LO 3.4.B – Heritability Studies with Twins and Adoptees

  1. How do monozygotic twins differ from dizygotic twins, and what does this difference reveal about the heritability of behavior?

  • Monozygotic (identical) twins share 100% of their genes, while dizygotic (fraternal) twins share 50%. Comparing the similarities in behavior between these types of twins helps determine the influence of genetics versus environment.

  1. Describe a basic design for a heritability study that involves both twins and adoptees.

  • A common study design compares the behaviors of monozygotic twins raised together, monozygotic twins raised apart, and dizygotic twins raised together, as well as adopted children raised by non-biological parents, to estimate the influence of genetics and environment.

LO 3.5.A, B – Intelligence Heritability and Interpretation

  1. To what extent is intelligence considered heritable?

  • Studies suggest that intelligence is moderately heritable, with estimates typically around 50%. Genetics play a significant role, but environmental factors, such as education and socioeconomic status, also contribute to intellectual development.

  1. How should group differences in intelligence be interpreted in light of genetic and environmental factors?

  • Group differences in intelligence should be interpreted carefully, considering the complex interaction between genetics, environment, culture, and socio-economic factors. It is essential not to attribute differences solely to genetics.

LO 3.5.C, D – Genes, Environment, and Intellectual Development

  1. How can the environment either hinder or promote intellectual development?

  • The environment can promote intellectual development through factors like access to education, nutritious food, and cognitive stimulation. Conversely, it can hinder development through poverty, malnutrition, or a lack of educational opportunities.

  1. Discuss the roles of nature and nurture in shaping behavior and intelligence.

  • Both nature (genetics) and nurture (environment) interact to shape behavior and intelligence. Genetic predispositions may set a baseline for intellectual potential, but environmental factors, such as upbringing and experiences, significantly influence how those potentials are realized.