heritability

Examples of heritability in the following topics:

• Genetic and Environmental Impacts on Intelligence

  • Some traits, like eye color, are highly heritable and can be easily traced.
  • However, even highly heritable traits are subject to environmental influences during development.
  • However, the heritability of IQ in juvenile twins is much lower at 0.45.
  • Thus, despite the high heritability of IQ, we can determine that there is an environmental influence as well.
  • This chart illustrates patterns in studies of heritability of traits in certain individuals.

• Nature vs. Nurture

  • Individual development, even of highly heritable traits such as eye color, depends not only on heritability but on a range of environmental factors, such as the other genes present in the organism and the temperature and oxygen levels during development.
  • However, some traits which reflect underlying talents and temperaments—such as how proficient at a language, how religious, or how liberal or conservative—can be partially heritable.
  • Trait A shows a high sibling correlation but little heritability (illustrating the importance of environment).
  • Trait B shows a high heritability, since the correlation of the trait rises sharply with the degree of genetic similarity.
  • Trait C shows low heritability as well as low correlation generally, suggesting that the degree to which individuals display trait C has little to do with either genes or predictable environmental factors.

• Gene-Environment Correlations: Nature or Nurture?

  • Parents create a home environment that is influenced by their own heritable characteristics.
  • Since intelligence is moderately heritable, it can be argued that intelligence in the child is inherited rather than a factor of the home environment created by the parents.
  • Evocative gene-environment correlation happens when an individual's (heritable) behavior evokes an environmental response.
  • Studies of adult twins are used to investigate which traits are heritable.

• Genetics, the Brain, and Personality

  • These findings suggest the heritability of some personality traits, implying that some aspects of our personalities are largely controlled by genetics.
  • Twin studies have shown that heritable factors are not the only predictor of personality or even diseases such as schizophrenia; the biological perspective does not fully address non-heritable factors.

• The Influence of Genes on Behavior

  • Behavioral genetics studies heritability of behavioral traits, and it overlaps with genetics, psychology, and ethology (the scientific study of human and animal behavior).

• Genetically Engineered Vaccines

  • Genetic engineering alters the genetic makeup of an organism using techniques that remove heritable material, or that introduce DNA prepared outside the organism either directly into the host or into a cell that is then fused or hybridized with the host.
  • This involves using recombinant nucleic acid (DNA or RNA) techniques to form new combinations of heritable genetic material, followed by the incorporation of that material either indirectly through a vector system or directly through micro-injection, macro-injection and micro-encapsulation techniques.

• Processes and Patterns of Evolution

  • A heritable trait that aids the survival and reproduction of an organism in its present environment is called an adaptation.
  • Explain why only heritable variation can be acted upon by natural selection

• Defining Population Evolution

  • Mutations occur spontaneously, but not all mutations are heritable; they are passed down to offspring only if the mutations occur in the gametes.
  • These heritable mutations are responsible for the rise of new traits in a population.

• Genetic Analysis

  • Mutation is random, undirected, heritable variation caused by alteration in nucleotide sequence at some point of DNA.

• Congenital Defects

  • Most of these are single gene defects, usually heritable.