Before I read this book my understanding of genetics was quite
naive, I thought DNA made proteins, and if there are mutations
in the DNA code then that leads to trouble, such as cancer. But
only 2% of the human genome makes protein - what is the other
98% for? Also consider this: A caterpillar that becomes a
butterfly has exactly the same DNA - so why do they look so
different? The answer is 'epigenetics'. Whenever two genetically
identical individuals are non-identical in some way we can
measure, this is called epigenetics. This also includes an
individual at different point in their life. For example why
does horrendous abuse as a child often lead to problems later in
life - is it psychological or is it embedded in the very genes
of the person? In the following sentence, before I read this
book, I mostly understood the word 'within'. "Histone
Acetylation and DNA methylation within a CpG motif in the
promoter region mediates gene expression ...." By half way
through this book I understood what this meant. Th