Define genetic diversity and use the example of the potato blight in Ireland to explain the importance of genetic diversity to a population.

Genetic diversity refers to the variety of genes within a population, species, or ecosystem. It is an essential component of biodiversity, and it contributes to the ability of a population or ecosystem to adapt and respond to environmental changes. High genetic diversity enables species to better survive and thrive in various environmental conditions, while low genetic diversity can make them more susceptible to diseases and other threats.

The Great Irish Famine, which occurred between 1845 and 1849, was caused by a potato disease called potato blight (Phytophthora infestans). This disease devastated the Irish potato crop, which was a staple food for a large portion of the population. As a result, over a million people died, and another million were forced to emigrate.

The Irish potato famine serves as a potent example of the importance of genetic diversity within a population. In this case, the potato crops in Ireland had very low genetic diversity, as they were primarily composed of a single potato variety called the "Lumper." This lack of genetic variation made the entire potato crop susceptible to the disease. With little to no resistance to the blight, the disease quickly spread and devastated the crops. If there had been higher genetic diversity among the potato varieties grown in Ireland, it is likely that some of the potato plants would have had natural resistance to the disease. This resistance would have slowed the spread of the disease, reducing its impact on the overall population. Therefore, this example demonstrates the importance of genetic diversity for a population in the face of potentially devastating environmental changes, such as the introduction of a new disease. Maintaining genetic diversity within populations plays a vital role in ensuring the long-term survival and adaptability of species in our constantly changing world.