What is the basis of Herman Muller's Ratchet theory?
A. That parthenogenesis does not increase genetic variability.
B. That once harmful mutations arise, asexual populations have no way of eliminating them.
C. That meiosis reduces the chromosome number in half.
D. That synapsis must occur for crossing over to take place.
E. That evolution is due to mutations, not crossing over.
Answer: B
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