Archives par mot-clé : Biodiversity

“Global climate change” does not cause species extinctions

by Paul Berth, March 22, 2019 in ScienceClimatEnergie


Contrary to what the media tries to make you believe, global climate change is not a major cause of species extinction. A recent study published in March 2019 in Frontiers in Ecology and the Environment shows that the major cause of extinction is the introduction of invasive alien species (IAS) into ecosystems. This phenomenon, well known to biologists and confirmed by the IUCN (International Union for the Conservation of Nature), is unfortunately little known to the general public.

Figure 1. Number of recent animal extinctions (IUCN categories “extinct” [EX] and “extinct in the wild” [EW]) for different groups of animals (figures from IUCN Table 3a). The colors provide information on the causes of the extinctions (“Driver”); for example dark purple is used for IAS (“Alien”), extinctions caused by local species (“Native”) are light purple. The category “Neither” includes other causes of extinction or unknown causes (source, Blackburn et al., 2019).

 

 

Global Warming off the hook? Alien species are primary cause of recent global extinctions

by University College London, March 3, 2019 in WUWT


Alien species are the main driver of recent extinctions in both animals and plants, according to a new study by UCL researchers.

They found that since 1500, alien species have been solely responsible for 126 extinctions, 13% of the total number studied.

Of 953 global extinctions, 300 happened in some part because of alien species, and of those 300, 42% had alien species alone listed as the cause of their demise.

The study, published today in Frontiers in Ecology and the Environment, used data from the 2017 IUCN Red List on the total numbers of species that are considered to have gone extinct globally since 1500.

In total, 261 out of 782 animal species (33.4%) and 39 out of 153 plant species (25.5%) listed aliens as one of their extinction drivers. In contrast, native species impacts were associated with only 2.7% of animal extinctions and 4.6% of plant extinctions.

 

 

The sixth mass genesis? New species are coming into existence faster than ever thanks to humans

by Prof. Chris D. Thomas, July 10, 2017 in TheConversation


Animals and plants are seemingly disappearing faster than at any time since the dinosaurs died out, 66m years ago. The death knell tolls for life on Earth. Rhinos will soon be gone unless we defend them, Mexico’s final few Vaquita porpoises are drowning in fishing nets, and in America, Franklin trees survive only in parks and gardens.

Yet the survivors are taking advantage of new opportunities created by humans. Many are spreading into new parts of the world, adapting to new conditions, and even evolving into new species … (…)

A new estimate of biodiversity on Earth

by University of Chicago Press Journals, August 30, 2017 in ScienceDaily


To date, about 1.5 million species have been formally described in the scientific literature, most of them insects. Proportionally, bacteria comprise less than 1% of all described species.

In a new paper published in The Quarterly Review of Biology (September 2017), researchers from the University of Arizona have estimated that there are roughly 2 billion living species on Earth, over a thousand times more than the current number of described species.