Yes, DNA can be changed after birth, but not in the way many people initially think. While the fundamental sequence of the DNA building blocks (A, T, C, G) remains largely constant, changes can occur in the structure of DNA and in its expression. This is a crucial distinction.
Types of DNA Changes After Birth:
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Structural Changes: These involve rearrangements within the DNA itself. Pieces of DNA can be moved, duplicated, or deleted. These structural changes can happen in any cell after birth. [Source: MedlinePlus Genetics: Structural changes can occur during the formation of egg or sperm cells, in early fetal development, or in any cell after birth. Pieces of DNA can be rearranged within one chromosome or transferred between two or more chromosomes.] This type of change directly alters the DNA sequence.
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Epigenetic Changes: These changes don't alter the DNA sequence itself but affect how genes are expressed. Think of it like changing the volume on a gene – turning it up or down, rather than changing the song itself. These modifications can be influenced by environmental factors and experiences. These changes are heritable, meaning they can be passed down through generations, however this does not alter the underlying DNA code. [Source: Harvard's Developing Child: When experiences during development rearrange the epigenetic marks that govern gene expression after birth, provides powerful experiences that can help shape the course of development.] [Source: BBC Future: This is the process of epigenetics, where the readability, or expression, of genes is modified without changing the DNA code itself.]
It is important to differentiate between changes to the DNA sequence and changes to the way DNA is expressed. Changing a birth certificate, for example, does not change the DNA sequence itself. [Source: NC Vital Records: After acceptance for registration by the State Registrar, no birth certificate can be altered or changed except by a request to the state office.]
Misconceptions:
A common misconception is that environmental factors directly change the DNA sequence. While the environment significantly influences epigenetic changes, affecting how genes are expressed, it doesn’t directly alter the underlying DNA code. [Source: Duke Alumni Magazine: Perhaps one of the only things we remember from eighth-grade biology is that DNA doesn't change. The 3 billion letters that make up your...]
Conclusion:
While the core DNA sequence remains largely stable after birth, structural changes and epigenetic modifications can occur, impacting gene expression and potentially an individual's health and traits.
