Assertion 4.19: No one has ever seen one species arise from another.
Analysis:
(i) As one example, in 1964, Dr. D. J. Reish removed 5 or 6 polychaetes (Nereis acuminata) from Los Angeles/Long Beach Harbor, and grew his sample to a size of thousands. in 1986, four pairs from this group were brought to Woods Hole Oceanographic Institution; the population at Woods Hole thus had gone through two bottlenecks, which are supposed to help drive evolution through genetic drift. In 1977-1978, two new cultures of N. acuminata were gathered from nearby Long Beach and Newport Beach, and grown under the same conditions as the Woods Hole sample. The three populations were later crossed, and it was found that the only crosses that would not produce viable offspring were the crosses involving the Woods Hole culture and the two new cultures. This signifies nothing less than speciation, and all in the laboratory as well. (Weinberg et al. 1992)
(ii) The young-earth creationist organization Answers in Genesis has has declared this an argument that "should definitely not be used."
References
Weinberg JR et al. 1992. Evidence for rapid speciation following a founder event in the laboratory. Science 46(4):1214-1220.