Accelerated modern human–induced species losses: Entering the sixth mass extinction

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Science Advances  19 Jun 2015:
Vol. 1, no. 5, e1400253
DOI: 10.1126/sciadv.1400253

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  • RE: Accelerated modern human-induced species losses: Enteringthe sixth mass extinction
    • John C. Briggs, Professor Emeritus, Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97333, USA

    Is a Sixth Global Mass Extinction Underway?

    John C. Briggs*
    In their recent article, published in Sciences Advances, Ceballos et al. (19 June 2015) endeavored to demonstrate that species extinctions by humans have caused the world to enter into its sixth mass extinction. As evidence, they compared extinction rates, among terrestrial vertebrates for the past few centuries, to the historical rate from the geological record. However, the historical rate was calculated only from data on mammal extinctions. The authors assumed that the historical mammal rate could be applied to all the other vertebrates (birds, reptiles, amphibians, and fishes). Using the mammal data, the authors determined that, without human influence, only nine vertebrate extinctions would have been expected since the year 1900.
    According to the Red List (IUCN, 2014), 198 extinctions were recorded for all terrestrial vertebrates since the year 1900. Compared to the expected nine extinctions during that time (Caballos et al., 2015), an increase of 189 appears to indicate a disastrous human influence. Extending back to the year 1500, a total of 338 were documented by the Red List. In addition to these numbers, the authors recognized 279 more species under “extinct in the wild” and “possibly extinct” categories. These figures produced a grand total 617 vertebrate species lost or presumed lost since 1500. These impressive numbers persuaded...

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    Competing Interests: None declared.
  • Are we nearing “Dooms Day”?
    • Amit Kumar Banerjee, Researcher, CSIR-Indian Institute of Chemical Technology, Hyderbad, India
    • Other Contributors:
      • Neelima Arora, Postdoctoral Fellow, Alumnous, CSIR-Indian Institute of Chemical Technology, Hyderbad, India

    Is human species who considered himself at the pedestal of superiority is inviting its own end? This is suggested in the present study by Ceballos et al. where they attempted to identify the next mass extinction. The pace at which species are getting extinct is alarming. Though there were reports earlier about the high rate of extinction of species in post industrialization era, yet lack of conclusive parameters and estimates always diluted the effect it should have on the policy makers and public. Comparison of “highly conservative modern extinction rate” and “background extinction rate” in this study provides a clear picture of rapid extinction of species. Man’s consumerist approach has been responsible for bringing on the possibility of sixth mass extinction that could very well have been avoided by adopting small measures in light of knowledge of ecology and modern science.
    Various anthropogenic factors like deforestation, aggressive exploitation of natural resources, mining and mindless dumping toxic wastes in natural environment may have plausible role for massive extinction. While we are trying to explore life on other planets, forgetting to concentrate to take measures to save our own planet. Man has lost the touch with nature and has become oblivious of his role of just a co-habitant on Earth not its master. Small steps like supporting the local animals and birds and separating solid wastes can go a long way in this direction. If we learn to appreciate t...

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    Competing Interests: None declared.
  • RE: Accelerated modern human–induced species losses: Entering the sixth mass extinction

    The article brings some interesting statistics showing the increase rate of extinctions among mammal and vertebrate. The over population of humans is obviously a great problem and has been for years. The population of humans in the early 1960s was around 3 billion and today over 7 billion and projected to be around 10 billion by 2020. No matter what mankind does that kind of overpopulation will put a stress on earth's ecosystems and animals and bio-systems. I remember scientists in the 1970s warning of overpopulation.. it is the fundamental basis for all the environmental problems. This article, if the stats are correct, bring this more to light.
    However this article's very important point looses credibility with statements like: "All of these are related to human population size and growth, which increases consumption (especially among the rich), and economic inequity". Over population increases consumption - period. Consumption of resources is world wide and is effected by population increases world wide, not just the rich ( and I assume you meant rich countries). And population increases are happening more rapidly in the less "rich" countries. "Overexploitation for economic gain" is minor compared to just the sheer volume of people living on the earth that consume air and food and resources and create waste. The destruction of the rain forest in South America since the 1940s to make cheap farming land for the poor has probab...

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    Competing Interests: None declared.
  • RE: Figure 2 legend reversed?

    Possibly it is my lack of understanding, but should the MORE conservative figure result in a smaller equivalent time to extinction?

    Looking at Table S2 "1900 to 2014 Highly Conservative" F/E for Amphibians (for example) shows '22'
    Looking at Table S2 "1900 to 2014 Conservative" F/E for Amphibians shows '100'.

    This is reversed from Figure 2, which shows "Very Conservative" for Amphibians at 10,000 years and "Conservative" for Amphibians at 2,200 years.

    Competing Interests: None declared.

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