Edward is a seven-year-old boy who has difficulty reading. His teacher refers him to the school psychologist to evaluate for a learning disability. The psychologist’s report concludes that Edward has dyslexia and mild central nervous system impairment.
Edward’s mother asks if the report means that her son has brain damage. The psychologist says, “He has impairments, but I wouldn’t say that he is brain-damaged.”
How would you explain this answer? What is dyslexia?
What are the different nuances of meaning associated with the expressions brain damage and central nervous system impairment?
Are we overly sensitive and fearful about the idea of brain damage in our culture?
Is this fear justified?
The human appendix, a vestigal extension off the large intestine, is homologous to a structure called a caecum, generally larger than our appendix, and houses bacteria that aid in digesting cellulose, the main component of plants.
Explain how the presence of the appendix might be used to show our common ancestry with other mammals, and determine what it might tell us about the dietary history of humans. Provide an example with your response.
Geneticists compare DNA base sequences among organisms and from this data determine a gene’s rate of evolution. Different genes have been found to evolve at different rates.
Explain why some genes might have faster rates of evolution than other genes as populations adapt to their environments, and give an example with your explanation.