Naturally Selected Haikus

Scikus dedicated to the proposition that all living things vary…

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Genes

Written in our genes
that bind and separate us,
Evolution sleeps.

We are all bound by the DNA in our cells into a single book of humanity, a single species. Yet the genes and other information encoded in DNA also spell out the tremendous differences we see in each other — in our sex, skin color, height, hair, personality, down to many of the diseases that plague us. Those variations are the raw materials on which natural selection acts to evolve new species.

But even the simplest characteristics are complex genetically. For example, sex appears to us like a simple dichotomy: male and female. Simple to control by a single genetic switch, right?

Contrary to common sense, our sex is built by a complicated choreography of genes and biological processes.

Here is a chart showing some of the genes involved in just one step of sex-determination, the development of testis in mouse:

Genes and pathways for developing testis in mouse (Figure 2 in Eggers and Sinclair, 2012, Creative Commons)