Inheritance for aliens

Imagine that humans have established communication with beings from another planet that neither age nor reproduce. Your task is to draw diagrams or schemas that convey to them how your parents contributed to you having the height or intelligence you have at 20 or so years. (The aliens have learnt English so you can use words on your diagrams.) The explanation conveyed in your diagrams or schemas might include genes, DNA, gene expression, embryology, environmental influences on your growth and development, and so on. Try to help the aliens by identifying what is left unexplained.

These beings are very intelligent themselves and are also scientific skeptics. If there is a hole in your explanation they will find it. You might want to preempt them by marking where you feel you need to find out more about how human inheritance works. You should also note that these aliens have received some information previously that emphasized meiosis and formation of the single-cell zygote. In return, they commented that zygotes have no height or intelligence and re-emphasized that they want to know how offspring get to have a height or intelligence similar (or not) to their parents.

The aim of this exercise is for you to think through something often avoided in biology, namely, the limitations of what most biologists actually know and don't know about inheritance.

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After you have tried this for yourself, review some phrases students used in a past class.