Origin of New SpeciesStreaming Video - 2015
When species exchange genes by interbreeding their morphological and genetic variation increases. Unusual or extreme variants are produced that could be the starting point of a new evolutionary trajectory leading to the formation of a new species. This program illustrates this with finches on Daphne. A hybrid male from the nearby island of Santa Cruz immigrated to Daphne. It was larger than the parental species, Medium Ground and Cactus Finches, it sang a unique song, and had a rare genetic marker. It bred with locally hatched Medium Ground Finches. After several years all members of this new lineage died in a severe and prolonged drought, except for a brother and a sister. These bred with each other, and so did their offspring. The new lineage is behaving as a new species by not breeding with any of the other finches on the island. It has retained the characteristics of large size, unique male song, and the rare genetic marker. After seven generations its future is uncertain in this strongly fluctuating environment, but it serves as an illustration of how hybridization can contribute to the formation of new phenotypes and the development of a new species.
Publisher: [Place of publication not identified] : Peter and Rosemary Grant, 
Copyright Date: ©2015
Characteristics: 1 online resource (1 video file (12 min., 50 sec.)) : sound, color.