The Tree Room : Trees matter :
In other cases, we may need to find the long lost relatives of a familiar species. Phylogenies help us do just that. For example, wild species that are closely related to domestic crops often carry variations on genes that have been lost in the highly bred and artificially selected crop species. These genes can affect pest resistance, disease resistance, yield, fruit quality, and any number of other plant traits. Once the handy genes are discovered in wild plants, they can be introduced to the crop plant via breeding or genetic engineering. By helping us identify these wild relatives, phylogenetics pinpoints new sources of potentially useful genes for agriculture. If you've eaten a salad recently, odds are that you've enjoyed lettuce grown with the help of genes from wild relatives!3
Identifying the wild relatives of the domestic tomato (Solanum) has helped us find new genes to improve our crops.