Jump to content

Recommended Posts

Species count put at 8.7 million


By Richard Black

Environment correspondent, BBC News


The black-capped woodnymph of Colombia was identified as recently as 2009

The natural world contains about 8.7 million species, according to a new estimate described by scientists as the most accurate ever.

But the vast majority have not been identified - and cataloguing them all could take more than 1,000 years.

The number comes from studying relationships between the branches and leaves of the "family tree of life".

The team warns in the journal PLoS Biologythat many species will become extinct before they can be studied.

Although the number of species on the planet might seem an obvious figure to know, a way to calculate it with confidence has been elusive.

In a commentary also carried in PLoS Biology, former Royal Society president Lord (Robert) May observes: "It is a remarkable testament to humanity's narcissism that we know the number of books in the US Library of Congress on 1 February 2011 was 22,194,656, but cannot tell you - to within an order of magnitude - how many distinct species of plants and animals we share our world with."

Now, it appears, we can.

"We've been thinking about this for several years now - we've had a look at a number of different approaches, and didn't have any success," one of the research team, Derek Tittensor, told BBC News.

"So this was basically our last chance, the last thing we tried, and it seems to work."

Dr Tittensor, who is based at the UN Environment Programme's World Conservation Monitoring Centre (Unep-WCMC) and Microsoft Research in Cambridge, UK, worked on the project alongside peers from Dalhousie University in Canada and the University of Hawaii.

The vast majority of the 8.7 million are animals, with progressively smaller numbers of fungi, plants, protozoa (a group of single-celled organisms) and chromists (algae and other micro-organisms).

The figure excludes bacteria and some other types of micro-organism.

About 1.2 million species have been formally described, the vast majority from the land rather than the oceans.

The natural world in numbers

  • Animals: 7.77 million (12% described)
  • Fungi: 0.61 million (7% described)
  • Plants: 0.30 million (70% described)
  • Protozoa: 0.04 million (22% described)
  • Chromists: 0.03 million (50% described)

Linnaean stepsThe trick this team used was to look at the relationship between species and the broader groupings to which they belong.

In 1758, Swedish biologist Carl Linnaeus developed a comprehensive system of taxonomy, as the field is known, which is still - with modifications - in use today.

Groups of closely related species belong to the same genus, which in turn are clustered into families, then orders, then classes, then phyla, and finally into kingdoms (such as the animal kingdom).

The higher up this hierarchical tree of life you look, the rarer new discoveries become - hardly surprising, as a discovery of a new species will be much more common than the discovery of a totally new phylum or class.

The researchers quantified the relationship between the discovery of new species and the discovery of new higher groups such as phyla and orders, and then used it to predict how many species there are likely to be.

"We discovered that, using numbers from the higher taxonomic groups, we can predict the number of species," said Dalhousie researcher Sina Adl.

"The approach accurately predicted the number of species in several well-studied groups such as mammals, fishes and birds, providing confidence in the method."

And the number came out as 8.7 million - plus or minus about a million.

Muddied watersIf this is correct, then only 14% of the world's species have yet been identified - and only 9% of those in the oceans.


The rate of species discovery has remained about even ever since Haeckel compiled his Kunstformen der Natur (Art Forms of Nature) a century ago"The rest are primarily going to be smaller organisms, and a large proportion of them will be dwelling in places that are hard to reach or hard to sample, like the deep oceans," said Dr Tittensor.

"When we think of species we tend to think of mammals or birds, which are pretty well known.

"But when you go to a tropical rainforest, it's easy to find new insects, and when you go to the deep sea and pull up a trawl, 90% of what you get can be undiscovered species."

At current rates of discovery, completing the catalogue would take over 1,000 years - but new techniques such as DNA bar-coding could speed things up.

The scientists say they do not expect their calculations to mark the end of this line of inquiry, and are looking to peers to refine methods and conclusions.

One who has already looked through the paper is Professor Jonathan Baillie, director of conservation programmes at the Zoological Society of London (ZSL).

"I think it's definitely a creative and innovative approach, but like every other method there are potential biases and I think it's probably a conservative figure," he told BBC News.

"But it's such a high figure that it wouldn't really matter if it's out by one or two million either way.

"It is really picking up this point that we know very little about the species with which we share the planet; and we are converting the Earth's natural landscapes so quickly, with total ignorance of our impact on the life in them."

Follow Richard on Twitter

Link to post
Share on other sites


I have thought about this and have following thoughts on this subject:

1) Species don't equal joonees. Within human there can be many life-forms e.g., the life of a Vesva (prostitute) has been considered a jooni as per Bhagat Trilochan jee's shabad (Ree Baayee, Gobind Naam matt Veesrai).

2) 8.4 million life forms are listed but it does not say that all 8.4 million life forms stay active at all times. I have a feeling that some life-forms stay dormant for some time and as per the will of Vaheguru, become active at the time desired by Vaheguru jee. Nothing becomes extinct from this world it just becomes dormant or goes out of our site but nothing is lost or becomes extinct.

Kulbir Singh

Link to post
Share on other sites

The classification that the Guru's used is obviously different to the ones that these scientists have used, that is all.

Who you going to follow your Guru or a scientist ?

Theories are always changing, at one time the universe was thought to be static, another theory is that once the universe has expanded it will then start to contract, now they say it will continue to expand for ever.

In chaupai Sahib Guru Ji says that all manifest world came out of God and it will merge back into God, sometimes it is interpreted as when God breathed out all manifest world emerged (as in big bang) and when He breathes back in all will merge back into Him, so who we going to believe ?

Link to post
Share on other sites

84 or Chauras!i I understand was a unit of measurement like we have the metric or the imperial system today. As we now measure metric units to 10,100,1000 and so on, but years ago the unit of measurement in the Punjab region was rounded of to 84. Hence 84 lakh or 84 man has also been used a example to measure weight. So the units are just an example of how vast the number of species there are. It's like saying that there are millions of life forms

Link to post
Share on other sites

After further research I have learned that the number '84' used for units of past measurement is flawed and disputed. Units similar to the metric system have been used in Punjab region for centuries. So the 84 lakh literally means 8.4 million species as stated in Sri Guru Granth Sahib. This is an amazing assessmen and this figure is more credible than the 8.7 million as it is from the supreme creator. I apologise for my previous flawed post, but hey I'm only a mortal!

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • advertisement_alt
  • advertisement_alt
  • advertisement_alt

  • Create New...

Important Information

Terms of Use