Oh I also think that scientific theories/things that interest you can be thrown in here as well, might make it a bit more open.
Now here’s something I find interesting.
The tree of life:
http://upload.wikimedia.org/wikipedia/commons/1/11/Tree_of_life_SVG.svgThat is the tree of life only showing organisms that we have mapped the genome of.
The Blue is bacteria; the green is archaea, which make up the prokaryotic forms of life (prokaryote means without a nucleus) and the pink colour are the eukaryotes (cells with a nucleus) such as animals, plants, fungi and protists.
Notice how the eukaryotes are more closely related to the archaea then to the bacteria.
Much like animals are more related to fungi than to plants.
This more simplified one shows general groupings:
http://upload.wikimedia.org/wikipedia/commons/7/70/Phylogenetic_tree.svgNow that’s just a general overview, but this follows on to some of the most interesting findings in evolutionary history, which can be shown with this diagram here.
http://en.wikipedia.org/wiki/File:Horizental-gene-transfer.jpgThat diagram shows horizontal gene transfer, this is something found in the prokaryotes which causes the tree model to well become more like a tangled mess of roots in those sections, horizontal gene transfer is the transfer of genes between organisms and even species, this is compared to vertical gene transfer, or what we'd usually call reproduction, the passing of genes to offspring.
That isn't the most interesting part though; you may have noticed the horizontal gene transfer between the bacteria and the eukaryotes.
Well this is where it does get interesting, as this isn't just standard horizontal gene transfer, this is endosymbiosis.
Now what is endosymbiosis you ask?
Well it's the theory that some bacteria incorporated themselves into other cells essentially becoming a component of the cell, now the theory is that mitochondria (sometimes referred to as the factory of the cell, as it is involved in the energy production of the cell), and plastids (organelles such as chloroplasts) were initially bacteria that incorporated themselves inside the cell.
Now Over time these bacteria became major components, to the point that some of their genes were incorporated into the nucleus (some were not, if you wish to learn more look at this
http://en.wikipedia.org/wiki/CoRR_Hypothesis).
Well what does this show us?
Well it shows us that our entire existence depended on several different forms of life forming together and producing an utterly new form of life, and along side this and the theory of how the nucleus came to be it is helping to explain how life went from unicellular to multicellular, and if that isn't important, I don't know what is.
