100 extinctions per million species per year

Started by PopeyesPappy, September 04, 2014, 11:28:28 PM

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PopeyesPappy

QuoteThe gravity of the world's current extinction rate becomes clearer upon knowing what it was before people came along. A new estimate finds that species die off as much as 1,000 times more frequently nowadays than they used to. That's 10 times worse than the old estimate of 100 times.

It's hard to comprehend how bad the current rate of species extinction around the world has become without knowing what it was before people came along. The newest estimate is that the pre-human rate was 10 times lower than scientists had thought, which means that the current level is 10 times worse.

Extinctions are about 1,000 times more frequent now than in the 60 million years before people came along. The explanation from lead author Jurriaan de Vos, a Brown University postdoctoral researcher, senior author Stuart Pimm, a Duke University professor, and their team appears online in the journal Conservation Biology.

"This reinforces the urgency to conserve what is left and to try to reduce our impacts," said de Vos, who began the work while at the University of Zurich. "It was very, very different before humans entered the scene."

In absolute, albeit rough, terms the paper calculates a "normal background rate" of extinction of 0.1 extinctions per million species per year. That revises the figure of 1 extinction per million species per year that Pimm estimated in prior work in the 1990s. By contrast, the current extinction rate is more on the order of 100 extinctions per million species per year.

Orders of magnitude, rather than precise numbers are about the best any method can do for a global extinction rate, de Vos said. "That's just being honest about the uncertainty there is in these type of analyses."

http://www.sciencedaily.com/releases/2014/09/140902151125.htm
Save a life. Adopt a Greyhound.

stromboli

Just the example of the differences made by one species, the wolf in Yellowstone Park, is enough to show how big an impact a species loss can make. The park was literally reshaped for decades because the Buffalo and Elk were allowed to roam at will, turning forest into greasslands. Reintroduction reversed that in jsut a decade or so.

Loss of a single top species like the African Elephant would cause a significant loss on the environment. One species breaks up thorn bushes, pulls down trees and create open grasslands for other species. They dig water holes in dry river beds, cause the spread of plants with their droppings and so on. Anything that impacts the environment ultimately impacts man. Protecting species and ecosystems is vital to all species at every level.

Hydra009

Quote from: Solitary on September 05, 2014, 11:18:00 AMIf just one species becomes extinct, like bees, we will too.  :eek: :boohoo:
Nitpick:  there are many thousands of known species of bees, several of which are economically important pollinators, with the European honey bee (Apis mellifera) as the most important.

We wouldn't necessarily go extinct from that particular species going extinct, but it would certainly hurt our harvests.

Jason78

Winner of WitchSabrinas Best Advice Award 2012


We can easily forgive a child who is afraid of the dark; the real
tragedy of life is when men are afraid of the light. -Plato

Mermaid

Every species of living thing affects others. That's the larger picture of what I learned during graduate school. The wolf example is very tangible, but there are billions of such interactions between and among species happening all the time. Life is very delicate and amazing.


A cynical habit of thought and speech, a readiness to criticise work which the critic himself never tries to perform, an intellectual aloofness which will not accept contact with life’s realities â€" all these are marks, not as the possessor would fain to think, of superiority but of weakness. -TR


josephpalazzo

The extinctions are part of God's plan. Who the fuck do you think you are to criticize?

Hydra009

 :eh:  Each bee in the picture is of a separate species.

Hydra009

One of us didn't.  I can assure you that biologists do not class all bees as the same species, hence the many different species names.  I though you were joking about that at first, but it seems you'd rather be wrong than be corrected.

PopeyesPappy

Bee isn’t a species any more than cat is. Lions (Panthera leo) and tigers (Panthera tigris) are separate species just as eastern honey bees (Apis cerana) and western honey bees (Apis mellifera) are. Lions and tigers are both members of the genus Panthera. Eastern and western honey bees are members of the genus Apis. Same genus. Different species.
Save a life. Adopt a Greyhound.

Solitary

From Wikipedia:


Now to make it even more complicated: Difficulty of defining "species" and identifying particular species
Main article: Species problem

It is surprisingly difficult to define the word "species" in a way that applies to all naturally occurring organisms, and the debate among biologists about how to define "species" and how to identify actual species is called the species problem. Over two dozen distinct definitions of "species" are in use amongst biologists.

Most textbooks follow Ernst Mayr's definition, known as the Biological Species Concept (BSC) of a species as "groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups". It has been argued that this definition of species is not only a useful formulation, but is also a natural consequence of the effect of sexual reproduction on the dynamics of natural selection.(Also see Speciation.)

Various parts of this definition serve to exclude some unusual or artificial matings:

    Those that occur only in captivity (when the animal's normal mating partners may not be available) or as a result of deliberate human action
    Animals that may be physically and physiologically capable of mating but, for various reasons, do not normally do so in the wild

The typical textbook definition above works well for most multi-celled organisms, but there are several types of situations in which it breaks down:

    By definition it applies only to organisms that reproduce sexually. So it does not work for asexually reproducing single-celled organisms and for the relatively few parthenogenetic or apomictic multi-celled organisms. The term "phylotype" is often applied to such organisms.

    Biologists frequently do not know whether two morphologically similar groups of organisms are "potentially" capable of interbreeding.

    There is considerable variation in the degree to which hybridization may succeed under natural conditions, or even in the degree to which some organisms use sexual reproduction between individuals to breed.

    In ring species, members of adjacent populations interbreed successfully but members of some non-adjacent populations do not.

    In a few cases it may be physically impossible for animals that are members of the same species to mate. However, these are cases, such as in breeds of dogs, in which human intervention has caused gross morphological changes, and are therefore excluded by the biological species concept.[dubious â€" discuss]

Horizontal gene transfer makes it even more difficult to define the word "species". There is strong evidence of horizontal gene transfer between very dissimilar groups of prokaryotes, and at least occasionally between dissimilar groups of eukaryotes; and Williamson argues that there is evidence for it in some crustaceans and echinoderms. All definitions of the word "species" assume that an organism gets all its genes from one or two parents that are very like that organism, but horizontal gene transfer makes that assumption false.

Charles Darwin wrote in chapter II of On the Origin of Species:

    No one definition has satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of a species. Generally the term includes the unknown element of a distinct act of creation.

But later, in The Descent of Man, when addressing "The question whether mankind consists of one or several species", Darwin revised his opinion to say:

    it is a hopeless endeavour to decide this point on sound grounds, until some definition of the term "species" is generally accepted; and the definition must not include an element that cannot possibly be ascertained, such as an act of creation.  :wall: :confused2: Solitary
There is nothing more frightful than ignorance in action.

Hydra009

Quote from: SolitaryI'm not joking!
Like I keep saying to no avail, encyclopedias are better for learning about a term than dictionaries.  As for bee species, [lmgtfy=number of bee species in the world]look it up[/lmgtfy].

QuotePlease explain what the other species of bees they are if they are not bees.
Not even wrong.

Okay, you know how the term "bird" refers to lots of different species of birds?  Yeah, it's like that.  Bee is a general term for lots of different species of bees.  So, you essentially commented that you're worried that the bird species might go extinct and then when someone corrected you and posted a chart containing many different bird species, you seriously argued that all birds are the same species because they have nearly the same characteristics apparently based on a very poor dictionary understanding of the term.

It's really hard for me to take something like that seriously.

Hydra009

Quote from: Solitary on September 06, 2014, 12:25:28 PMThat definition I gave is wrong I guess. You are correct! I stand corrected
Yay! Thank you.  Now we can get back to the topic at hand.

Solitary

Not so fast! We still have to agree on the definition of species to determine if all bees were destroyed mankind would die off. Which of the 24 different definitions do you want to use?

http://evolution.berkeley.edu/evosite/evo101/VADefiningSpecies.shtml
Quote


Over two dozen distinct definitions of "species" are in use amongst biologists.

A species is often defined as a group of individuals that actually or potentially interbreed in nature. In this sense, a species is the biggest gene pool possible under natural conditions.

For example, these happy face spiders look different, but since they can interbreed, they are considered the same species: Theridion grallator.

That definition of a species might seem cut and dried, but it is notâ€"in nature, there are lots of places where it is difficult to apply this definition. For example, many bacteria reproduce mainly asexually. The bacterium shown at right is reproducing asexually, by binary fission. The definition of a species as a group of interbreeding individuals cannot be easily applied to organisms that reproduce only or mainly asexually.       a dividing streptococcus bacterium

Also, many plants, and some animals, form hybrids in nature. Hooded crows and carrion crows look different, and largely mate within their own groupsâ€"but in some areas, they hybridize. Should they be considered the same species or separate species?

If two lineages of oak look quite different, but occasionally form hybrids with each other, should we count them as different species? There are lots of other places where the boundary of a species is blurred. It’s not so surprising that these blurry places existâ€"after all, the idea of a species is something that we humans invented for our own convenience!
Why is this getting like reading the Bible? It's because even science is ambiguous with definitions because they are all made up for our use, depending on what we want them to mean. Solitary
There is nothing more frightful than ignorance in action.

josephpalazzo

Here's the most general definition:

A species is often described as the largest group of organisms capable of interbreeding and producing fertile offspring.