Between 1957 and 1961, thousands of expectant women in 30 different nations ingested a common antinausea drug of the time known as thalidomide. A study of found that if the thalidomide was ingested only after day 54, then no harm occurred to the fetus, but if ingested prior to day 54 the fetus could be born with malformed or absent limbs.

A study of those newborn babies

Explanation:  

Studying the infants from these pregnant women lead the researchers to find out that this drug interfered with the process of limb formation if the pregnant woman had taken this drug anytime during the 26 days critical for limb formation and development. In this way, it makes for an instance where nurture had disrupted nature.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

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