A+Population+of+Billions+May+Have+Contributed+to+This+Bird's+Extinction

A Population of Billions May Have Contributed to This Bird's Extinction Steph Yin November 16, 2017 https://www.nytimes.com/2017/11/16/science/passenger-pigeons-extinction.html?rref=collection%2Fsectioncollection%2Fscience&action=click&contentCollection=science®ion=rank&module=package&version=highlights&contentPlacement=2&pgtype=sectionfront

Bailey Library and Archives, Denver Museum of Nature and Science

Summary: Passenger pigeons were among the most abundant birds until the early 20th century. In fact, whenever they migrated, they would do it in such a big volume that they would block out the Sun. As stated in the previous sentence, they have been extinct since the early 20th century. Most people think that it is because of human activity; however, there is another possible reason for their extinction: natural selection. Recent research has shown that natural selection was extremely efficient in flocks of birds, but it was not efficient for small groups. In fact, in large groups, natural selection took an extremely big toll on the population of pigeons since it reduced genetic diversity. While examining the genome of the passenger pigeon, researchers found that there was high genetic diversity in the sections that get rearranged between generations, and low diversity in those who don't. However, further research indicates that passenger pigeon populations were stable for the past 20,000 years. Most of these researches suggest that passenger pigeons hyper-adapted to such a large population.

Relation to Class: The themes of genetic diversity and extinction have been mention a few times in APES, particularly in chapter 6 pages 146-150 and chapter 25 pages 684-690. These two chapters focus on the causes of extinction. Chapter 25 particularly explains how much damage humans have done to species, while chapter 6 focuses on the more natural parts of extinction. However, this article points out that it was not solely human activities that lead to the extinction of the passenger pigeon.

Opinion: It interests me that this article mentions human activities minimally and instead focuses about the mistakes of the pigeons' genetics. It was also interesting that the researches contradicted the current scientific status quo by saying that in large groups, natural selection sometimes does more harm than good, and they have specific evidence to back this unorthodox claim up. It is also intriguing that there are certain sections in a pigeon's DNA that can change across generations, but there are other sections of DNA that remain virtually static.

Law: Although the passenger pigeon was eradicated before the enactment of this law, there still is some relevance today. The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend. It is administered by the U.S. Fish and Wildlife Service (Service) and the Commerce Department's National Marine Fisheries Service (NMFS). The Service has primary responsibility for terrestrial and freshwater organisms, while the responsibilities of NMFS are mainly marine wildlife such as whales and anadromons fish such as salmon. Under the ESA, species may be listed as either endangered or threatened. "Endangered" means a species is in danger of extinction throughout all or a significant portion of its range. "Threatened" means a species is likely to become endangered within the foreseeable future. All species of plants and animals, except pest insects, are eligible for listing as endangered or threatened. For the purposes of the ESA, Congress defined species to include subspecies, varieties, and, for vertebrates, distinct population segments.