Do you think that all of our body’s structures are adaptations produced by natural selection? How do you explain the presence of nipples in males? Is natural selection the only driving force behind evolution? Does natural selection always favor complex structures over simple ones? Find some current answers to all these questions and more in NewScientist.com’s guide to 24 Myths and Misconceptions about Evolution.
In class today, a student from Cs asked how blood cells travel into the bloodstream if they are created in the bone marrow found at the center of long bones. Take a look at the pic below, notice that blood vessels (red and blue tubes) lead into the center of the bone (spongy bone). Blood cells can travel into the bloodstream using these pathways.