Just wondering today. As we evolved into higher beings..from archea, to fungi, to homosapiens, our genome grew due to new requirements and survival.

Is our genome at this time expanding at all. I would think it has to, as there's a flux in certain genes favored by natural selection. Some simply die off (tail)

some increase (brain size?). Is there any reason as to why it would shrink?

 

~ee

It is incorrect to assume that complex organism acquired new genetic functions. In fact, eukaryotes have lost a lot in terms of metabolic capabilities. In turn regulatory and signaling function have become more complex in eukaryotes. For example, the nematode Caenorhabditis elegans has about the same number (or slightly more) than humans. Most of the genome are not genes but are remnants of our evolutionary history (e.g. viral sequences), though it is quite unclear how relevant they are for normal cell/tissue/organismal functions. 

Well if we're talking about shear physical size of the genome, couldn't we assume it increases via viral insertion, after every generation?

Now relative to the functioning/usefull gene sequences, that number could go up or down.?...

Or stay the same?