When someone informs you that it (whatever “it” is) is in their genes – so forget asking them to grow up and accept some responsibility – show them this article:
…. new large-scale studies of DNA are causing her and many of her colleagues to rethink the very nature of genes. They no longer conceive of a typical gene as a single chunk of DNA encoding a single protein. “It cannot work that way,” Dr. Prohaska said. There are simply too many exceptions to the conventional rules for genes.
It turns out, for example, that several different proteins may be produced from a single stretch of DNA. Most of the molecules produced from DNA may not even be proteins, but another chemical known as RNA. The familiar double helix of DNA no longer has a monopoly on heredity. Other molecules clinging to DNA can produce striking differences between two organisms with the same genes. And those molecules can be inherited along with DNA.
The gene, in other words, is in an identity crisis. – “Now the Rest of the Genome” by Carl Zimmer (New York Times, November 10, 2008)
And will somebody please text Lamarck, and tell him he’s being rehabilitated?