50 Inherited Traits Examples

Inherited traits refer to the physical or behavioral features transferred from parents to offspring through genes. They are juxtaposed to acquired traits, which we develop through environmental, social, and contextual factors.

The process of transmission occurs during reproduction, where genes—the basic units of heredity—located in the DNA of each parent combine to form the genetic make-up of the offspring (Malmir, Farhud, & Khan Ahmadi, 2016).

These traits include features like height, eye color, hair color, and the susceptibility to certain diseases.

Trait inheritance is the foundation of evolution. Short and straightforward, evolution is a process driven by genetic variation and natural selection. Variations are created by genes, and these variations are passed between generations.

Through the process of natural selection, traits that enhance survival and reproduction tend to prevail (Jantsch, 2019).

Inherited Traits Examples

How Hereditary Traits Work

In humans, the inheritance of traits is a complex process (Stansfield, 2011). For instance, traits like skin color are polygenic (determined by more than one gene), leading to a wide range of variations within the population.

Furthermore, recent research suggests that the environment can cause alterations in gene expression, a concept often referred to as epigenetics (Cabej, 2012).

It is essential to understand this nuance. Traits do not pop up out of thin air. They are controlled by genes that are passed down from one generation to the next, and these genes can only have come from a parent (Berent, 2020).

One common misconception about inherited traits is that they are solely dependent on one’s parents. Although parents greatly influence the traits of their offspring, variation also comes from mutations, sexual recombination, and potentially from the external environment (Cabej, 2012).

Example: Consider the heredity of eye color. Parents carry genes for eye color. If both parents carry the gene for blue eyes, their child is likely to have blue eyes (Stansfield, 2011). However, if one parent carries a gene for brown eyes—which is dominant over blue eyes—the child could feasibly have brown eyes. Additionally, an unexpected mutation could introduce a unique color variation not present in the parent genes.

Humans have made significant strides in understanding inheritance. Now, modern technological advancements are allowing us to look even deeper at the molecular level. Understanding the flow of hereditary information, Darwin’s theory from 150 years ago, is still fundamental in today’s biological research (Liu & Chen, 2018).

Today, researchers are working to understand how variations at the molecular level can affect phenotype expression and cause diseases. Shaping our understanding of human nature, these inherited traits provide a comprehensive narrative of our physical and psychological make-up (Berent, 2020).

Dominant vs Recessive Inherited Traits

Dominant and recessive refer to how specific traits, diseases, or conditions are handed down from parents to their offspring through genetic codes.

Each cell in the body contains 23 pairs of chromosomes, half from the mother and half from the father, resulting in a total of 46 chromosomes. These chromosomes carry genes, which are responsible for influencing traits in a person (Stansfield, 2011).

Dominant traits are those that are expressed when at least one copy of the dominant allele (a version of a gene) is present in the genotype (the individual’s genetic make-up). In other words, if an individual inherits a dominant allele from either parent, the dominant trait will be expressed (Malmir, Farhud, & Khan Ahmadi, 2016).

For example, in the case of eye color, the allele for brown eyes is dominant. This means that if a person has one allele for brown eyes and one for blue eyes, the person will have brown eyes (Stansfield, 2011).

Recessive traits, on the other hand, require two copies of the recessive allele in order to be expressed. If an individual only has one copy of the recessive allele, the trait will not be visible, although the person will be a carrier of that trait and can pass it on to their offspring. For example, as blue eyes are a recessive trait, both parents must contribute a blue-eye gene for the child to have blue eyes (Liu & Chen, 2018).

Another instance of this dominance-recessive relationship is observable in the genetic transmission of certain diseases. Cystic fibrosis, for instance, is a recessive genetic disorder. This means that an individual must inherit two copies of the abnormal CF gene (one from each parent) to have the disease (Stansfield, 2011).

Example: If both parents are carriers of the cystic fibrosis gene but do not have the disease (as they each have only one copy of the gene), there is a 25% chance that their child will inherit two copies of the abnormal gene and thus have cystic fibrosis. There’s a 50% chance that their child will be a carrier like them (inherit one abnormal gene and one normal gene), and a 25% chance that the child will neither be a carrier nor have the disease (inherit two normal genes).

Though the mechanics may seem simple, trait inheritance is far from straightforward. Many traits are influenced by multiple genes, a feature not captured in simple dominant-recessive models. Furthermore, research is revealing that we can’t entirely predict how genes behave, as they can interact with other genes and the environment in ways that scientists are still uncovering (Berent, 2020).

Feature	Dominant Trait	Recessive Trait
Definition	Trait that appears when at least one dominant allele is present	Trait that appears only when two recessive alleles are present
Representation	Typically denoted by a capital letter (e.g., ‘A’)	Typically denoted by a lowercase letter (e.g., ‘a’)
Phenotype Expression	Appears even if only one parent passes on the allele	Appears only if both parents pass on the allele
Example: Eye Color	Brown Eyes (B)	Blue Eyes (b)
Example: Tongue Rolling	Ability to roll tongue (R)	Inability to roll tongue (r)
Example: Earlobes	Free earlobes (E)	Attached earlobes (e)
Example: Hair Type	Curly hair (C)	Straight hair (c)
Genetic Combination	Homozygous dominant (AA) or Heterozygous (Aa)	Homozygous recessive (aa)
Inheritance	At least one parent must have the dominant allele	Both parents either need to be carriers or express the recessive trait

Inherited Traits vs Acquired Traits

Inherited traits and acquired traits constitute two classifications of traits that characterize an organism’s phenotype.

Inherited traits result from the genetic material passed down from parents to offspring (Malmir, Farhud, & Khan Ahmadi, 2016).

Acquired traits, on the other hand, do not stem from the parent’s genetic contribution. Instead, they originate during an organism’s lifespan as a result of environmental influences or the organism’s experiences (Stansfield, 2011). These might involve physical changes, like a person’s muscles becoming stronger through regular exercise, or behavioral changes, such as learning to play a musical instrument.

Note that while acquired traits can influence an organism’s physiology or ability, they are fundamentally not passed down through generations via genes.

It’s a fine line that we tread. Inherited traits are determined by our genes, which we have at birth. On the opposite side, acquired traits are largely influenced by environmental factors or experiences. For instance, a child might inherit a predisposition for musical talent (an inherited trait) from their parents, but the ability to play Beethoven’s Symphony No. 9 on the piano is an acquired trait, resulting from dedicated practice and instruction.

Historically, there has been substantial debate over inherited and acquired traits, especially over whether acquired traits can become inherited. The concept that acquired traits could be inherited was buoyed by Jean-Baptiste Lamarck in the early 19th century. However, this idea—known as Lamarckism—has largely been debunked by modern genetics, which asserted that DNA, not experience, determines inherited traits (Stansfield, 2011).

However, it’s not as simple a distinction as it might initially seem. In recent years, our understanding of inheritance has deepened, and the boundary between inherited and acquired traits is not as firm as once thought. The realm of epigenetics has blurred the line, suggesting that environmental influences can, in fact, alter gene expression and potentially be passed onto future generations (Cabej, 2012).

This idea doesn’t indicate that Lamarckism is correct but simply demonstrates that our understanding of inheritance and acquired traits continues to evolve.

Feature	Acquired Traits	Inherited Traits
Definition	Traits developed during an individual’s lifetime due to environmental factors, experiences, or learned behaviors.	Traits passed from one generation to the next through genes.
Origin	Result from an individual’s experiences and environment.	Result from genetic information passed down by parents.
Examples	Learning a language, acquiring a skill like playing an instrument, or getting a scar from an injury (see: examples of acquired traits).	Eye color, hair texture, certain genetic diseases, height (though environment can play a role too).
Transmission to Offspring	Not passed down to offspring through genes.	Passed down to offspring through genes.
Duration	Can change over an individual’s lifetime.	Typically remain constant over an individual’s lifetime, though some may only manifest at certain ages.
Impact of Environment	Directly influenced by the environment, experiences, and learning.	Largely unaffected by individual experiences, but the expression can sometimes be influenced by the environment (e.g., nutrition affecting height).

Conclusion

The nuances of inherited traits and their classifications as dominant or recessive underpin our understanding of how we, and all living organisms, evolve and exhibit the physical and behavioral traits we do. This knowledge, steeped in the pioneering work of Gregor Mendel and elaborated through modern genetics and the intriguing field of epigenetics, continues to evolve. While our understanding of the mechanics of inheritance becomes deeper and more intricate, the essential facts remain the same: our traits are a direct product of our genes, shaped subtly by our experiences and the world around us. Our continued exploration into the science of inheritance promises not only greater self-understanding, but also holds the prospects for exciting advances in medicine, anthropology, and various other fields.

References

Berent, I. (2020). The blind storyteller: How we reason about human nature. Oxford University Press.

Cabej, N. (2012). Epigenetic principles of evolution. London: Elsevier.

Jantsch, E. (2019). Unifying principles of evolution. In The evolutionary vision (pp. 83-115). Routledge.

Liu, Y., & Chen, Q. (2018). 150 years of Darwin’s theory of intercellular flow of hereditary information. Nature Reviews Molecular Cell Biology, 19(12), 749-750.

Malmir, M., Farhud, D., & Khan Ahmadi, M. (2016). . Inheritance of Acquired Traits: Expression of Happiness and Violence Genes. Laboratory & Diagnosis, 7(30), 27-34.

Stansfield, W. D. (2011). Acquired traits revisited. The american biology Teacher, 73(2), 86-89.