[Biology Class Notes] on Difference Between Acquired and Inherited Traits Pdf

Charles Darwin and Jean-Baptiste Lamarck were both pioneering evolutionary scientists but they had different ideas about exactly how organisms could change over time. In this lesson find out more about Darwin’s and Lamarck ‘s ideas!

What is Evolution?

Have you ever seen a giraffe sticking out its long neck to touch some leaves on a tall branch of the tree and asking how long its neck was? Most people believed many years ago that traits, like the long neck of the giraffe, just existed and didn’t change with time. 

Inherited and Acquired Traits 

The Traits acquired are the ones a person develops during his lifetime. Those aren’t passed from generation to generation. On the other hand, hereditary characteristics have been present in the individual since his birth and are passed on from one generation to the next.

Acquired Traits

The character developed in an individual as a consequence of environmental influence is an Acquired Trait. These characteristics are not coded in a living organism’s DNA, and can not, therefore, be passed onto future generations.

Examples of Acquired Trait

• When a person learns to ride a bike, it is an acquired trait. 

• Reading books, developing skills etc are examples of Acquired traits.

• Acquired behavior traits are commonly seen in tasks such as playing musical instruments, training dogs (teaching him tricks). 

• Acquired behavior traits can also be seen when a student studies.

• Scars are also an example of acquired physical traits.

• Hormonal changes during puberty are also examples of acquired traits which cannot be passed to the future generation.

• Muscles developed after bodybuilding and working out are examples of acquired traits.

Acquired Characteristics 

Acquired and Inherited traits

1. Traits acquired by organisms during their lifetime

2. Not passed from one generation to another

1. Traits controlled by genes.

2. Passed on from one generation to the next.

Purchased Traits

1. Somatics is variable.

2. Acquired features developed due to the effects of environmental factors, the use and disguise of organs, and special (conscious) efforts. 

3. Throughout an individual’s lifetime, these features develop, and that individual’s with death. 

Example: learning dance, music, and so on, and the muscular body of a wrestler.

Inherited Traits

1. Those are variations in genetics. 

2. Inherited features evolve due to genetic material rearrangement and mutation. 

3. The parents transfer those traits (inherited) to their offspring. These aren’t dying but passed on to the next generation. 

Example: earlobe attached or free, and curly hair.

Darwin, Lamarck and Acquired Traits

Initially, Lamarck hypothesized that the acquired traits could be transmitted from parents to offspring, thus making the organism more environmentally appropriate. Darwin later removed this hypothesis from his publication – Theory of Evolution, once he had sufficient evidence to prove that the traits acquired are not passed from one generation to the next. 

For example, a bodybuilder-born offspring does not necessarily need to have extremely large muscles. This is because the bodybuilder had developed the muscles during his lifetime.

Inherited Traits

These are the traits that are inherited from parents to offspring. Hair, skin, the color of the eyes, a form of the body, height, and susceptibility to other diseases are some of the examples of human inherited traits. An individual’s inherited characteristics are determined by his/her genes. 

In a human body, one single cell contains 25,000 to 35,000 genes. These genes carry the traits that an individual has inherited from his parents. 

In his studies with the pea plant, Gregor Mendel clarified the idea of inherited traits. He depicted that the traits visible in the phenotype are called the dominant traits, while the non-visible traits are known as recessive traits.

Examples of Inherited Traits

• Curly hairs, Dimples and other physical features are commonly seen as inherited traits. These traits are passed to further generations. Also, these acquired traits are in control of the human being.

• Inheritance can also be responsible for Green/Red Color Blindness. If a person is suffering from color blindness, c
  hances arise that the child will also suffer from the same.

• Eye color, skin tone, Blood group etc. are also inherited from a parent to the child.

• In some cases, height is also an inherited trait. But, according to some studies, height should not be considered an inherited trait. This is because height is a combination of more than 700 genes in the human body. Therefore, it is not appropriate to consider height as inherited on the basis of just one gene. 

Mendel Clarified The Inherited Characteristics By The Following Inheritance Laws

1. Law of Dominance: When there are two alternative types of character in an adult, only one form expresses itself in the offspring of F1 and is called the dominant trait, while the form which does not express itself is called the recessive trait.

2. Segregation Law: The alleles show no mixing and are recovered as such in the F2 generation, although one of them is not seen in the F1 generation. 

3. Law of Independent Assortment: When two pairs of traits are recombined, the segregation of one pair of characters during gamete formation is independent of the other pairs of characters. 

Difference between Lamarckism and Neo–Lamarckism