21 - 30 of 44 Answers
May 6, 2010:
Where do new genes come from?
January 13, 2010:
Is it true that in earlier times humans were all O blood type (in ABO blood group) and that A, B and AB blood type occurred later by mutation of the O blood type gene?
December 11, 2008: I've read that humans gained about 200cc of brain capacity some 100,000 years ago. Is this true? Also, how did human brains get to be so big?
October 23, 2008:
Hypothetically, if all the dogs in the world could somehow run wild, how many generations would it take before they all looked the same?
May 8, 2008:
You stated in an earlier answer that human chromosome 2 is made up of two fused chromosomes from the common human-chimp ancestor. This fused chromosome then spread throughout the human population. Could common design be an alternative explanation? What specifically RULES out common design for the fused chromosome?
December 6, 2007:
What causes changes in DNA? Do accumulative changes in DNA lead to evolution? Could you explain that process to me. How does the DNA know that it needs to adapt? It is my understanding that the germ cells that pass traits to the next generation are isolated from the cells that are affected by the environment. How does that knowledge and or adaptation get passed to the next generation?
November 30, 2007: The field of evo-devo has started showing that big evolutionary changes can happen with only limited genetic changes. Changes in genes that control the expression of other genes can have dramatic effects on an organism. A small change in the expression of one protein can create a much larger and different beak in a bird, for example. So evolution does not require invention of entirely new genes -- just tinkering with expression of the ones already in existence.
Question: Is there any indication that these control genes might be unusually susceptible to mutation? Or maybe there are lots more versions of these control genes, creating more places for selection to act on? If so, this would help explain why evolution sometimes occurs very rapidly.
August 29, 2007:
If evolutionary theories hold true, how did the leap from 24 to 23 chromosome pairs occur from 'apes' to humans? How is it possible for two chromosomes to merge into one, and for the resulting species to survive to breed?
March 30, 2007:
How do we know that evolution isn't a hoax?
December 15, 2006:
Due to slight changes in their genetic makeup, bacteria have been able to successfully develop antibiotic resistance. Would it be possible for humans to develop this kind of resistance as well? Could we make this process work for us and become resistant to, for example, the mutations caused by cigarette smoke or UV light?