The teacher firstly explain the difficulty of pooving natural selection. Indeed, he menctions that most of the clear examples we can use are man-made! But he explains that natural selection in nature takes a long time.

He uses an hypothethical example about bacteria, and abaout how a single modification in the cell wall of a bacteria could enable that single individual to survive and reproduce while the others perished due to a medicine.

Then he tells us an example, a true story we’ve already menctioned in the classroom: the case of the pepper moths.

In a forest of white trees, peppered moths were less likely to survive than white moths, whick were better camouflaged and fitter; but some years after, in the industrial revolution, polution darkened the colour of the trees, making the white moths more easy to eat for birds and giving an advantage to black moths.

Finally he tells us to always ask the question “Why?” to our surroundings, like for example “Why is that horn curvy?” or “Why is there a spot on this fish head?” and searching or reasoning an answer.

Video: http://www.5min.com/Video/Natural-Selection-in-Action-150610695

Cheers 🙂

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