September 30, 2010
Plants As Threatened With Extinction As Animals

Habitats keep shrinking with no end in sight.

A global analysis of extinction risk for the world's plants, conducted by the Royal Botanic Gardens, Kew together with the Natural History Museum, London and the International Union for the Conservation of Nature (IUCN), has revealed that the world's plants are as threatened as mammals, with one in five of the world's plant species threatened with extinction. The study is a major baseline for plant conservation and is the first time that the true extent of the threat to the world's estimated 380,000 plant species is known, announced as governments are to meet in Nagoya, Japan in mid-October 2010 to set new targets at the United Nations Biodiversity Summit.

Some highlights:

  • Of almost 4,000 species that have been carefully assessed, over one fifth (22%) are classed as Threatened

  • Plants are more threatened than birds, as threatened as mammals and less threatened than amphibians or corals

  • Gymnosperms (the plant group including conifers and cycads) are the most threatened group

  • The most threatened habitat is tropical rain forest.

  • Most threatened plant species are found in the tropics

  • The most threatening process is man-induced habitat loss, mostly the conversion of natural habitats for agriculture or livestock use

Population growth and industrialization will both accelerate the conversion of habitats to agriculture. The next couple billion growth in human population will much more environmental damage than the previous two billion because the reserves have shrunk so far. Plant and animals that could still survive in, say, half the original area can't survive in a tenth the area or after their natural environment is totally gone.

Share |      Randall Parker, 2010 September 30 10:42 PM  Trends Extinction


Comments
PacRim Jim said at September 30, 2010 11:09 PM:

Humanity has placed its bet on nanotechnology to clean up the environment, both by reducing industrial pollution and bioremediation.

Engineer-Poet said at October 1, 2010 6:21 AM:

Placed a bet?  Looks more like near-total neglect to me.

It reminds me of this old joke:

Q:  How many hardware engineers does it take to fix a lightbulb?
A:  We'll fix it in software.

Q:  How many software engineers does it take to fix a lightbulb?
A:  We'll put it in the manual.

Q:  How many tech writers does it take to fix a lightbulb?
A:  The user can figure it out.

Bruce said at October 1, 2010 8:16 AM:

Don't take stories like this seriously. Its just trolling for grant money.

"Conservationists are overestimating the number of species that have been driven to extinction, scientists have said.
A study has found that a third of all mammal species declared extinct in the past few centuries have turned up alive and well.

Some of the more reclusive creatures managed to hide from sight for 80 years only to reappear within four years of being officially named extinct in the wild."


http://www.dailymail.co.uk/sciencetech/article-1315964/One-extinct-animals-turn-again.html

Chris T said at October 1, 2010 9:25 AM:

I've personally become somewhat skeptical of announcements that x species are endangered. The definition of species has never been particular definite and genetics has revealed that the idea of discrete species doesn't really hold water.

Chris T said at October 1, 2010 9:30 AM:

To illustrate the problem, depending on your definition, there can be less than ten million species on Earth to over 100 million. Endangered estimates tend to use more liberal definitions.

PacRim Jim said at October 1, 2010 3:17 PM:

I promise that, as soon as the Sony BioGen 1000 becomes available, I'll sit in my attic and use it to churn out dozens of new species every day. Bioengineering will cure extinction.

JP Straley said at October 1, 2010 4:18 PM:

In late September of this year I travelled through southern Italy. I was in the agricultural areas as well as the tourist area of the west coast, south of Naples. Guess what. No birds. Even on cliff sites facing the Med, no sea birds. These ought to be prime nesting areas.) We ate outdoors a lot, great food & wonderful ambiance. Guess what. No flies. Italy was deforested by the Romans, and it remains deforested. It's a man-created environment. And there are no birds. Yes, the habitat destruction is a major factor in the absence of birds. But there's got to be a lot of toxicity around for flies to disappear.

JP Straley

Russ said at October 1, 2010 5:46 PM:

I noticed the lack of birds years ago in Italy, it's nothing new. Hopped from Italy to Greece and was shocked to hear songbirds again.

Biobob said at October 1, 2010 9:01 PM:

PacRim Jim, it's simply not a matter of pollution. Rather, plant species extinction is almost entirely a matter of habitat destruction, human spread of plant diseases and introduction of exotic species of plant and plant feeding species. Certainly nanotech is in it's infancy, has good potential, but I would not count on it for anything in particular at this point.

Chris T has a point - just not the one he intends. The definition of species is quite definite; however far too many biologists ignore it since it does not fit their narrative. A species is a discrete breeding unit of life that does not normally exchange genetic material with any other species; when genetic material IS exchanged with another species, any surviving offspring are sterile/non-viable. There certainly are major issues with bacterial "species" since widely separate previous defined "taxa" promiscuously share/exchange genetic material and remain viable. And a good example, certainly dogs, wolves and coyotes are all one species, etc. We have no accurate idea of the number of species present on earth since minimal funding is directed at finding and describing the many species present in tropical regions. In addition, many species can only be determined by genetic analysis and such analysis of the millions of species is in its infancy.

Certainly species will continue to be rubbed out by human conversion of habitat and other activities and I doubt anything useful will be done about it, by in large, except activities like cleaning house while it burns.

Chris T said at October 2, 2010 9:11 AM:

Biobob - The species definition you suggest also breaks down when applied to plants. Plants with very different phenotypes can hybridize to produce viable offspring.

Geographic isolation is frequently used to differentiate different species even if the two groups could freely interbreed if brought together. As you said, we simply don't have the resources or inclination to find out. Hence my skepticism of the high numbers frequently promulgated.

Biobob said at October 2, 2010 12:02 PM:

Chris T, if organism can hybridize in nature (without human intervention) and can produce viable offspring, then they are NOT species. It's that simple. There is no breakdown in the definition, merely in what the human biologist concluded were species. The breakdown is in human assumption, as usual, not in the definition.

If the populations are truly geographically isolated in "genetic time" as well as in human referenced time, then I would agree they are species. Many species supposedly isolated from each other are actually NOT if the proper time reference is used. Human assumptions about species mobility are often flawed, as evidenced by the recently discovered and sometimes global dispersal of insects/spiders via atmospheric drift. Eventually the isolation, if complete will result in true species formation in fact as well as by inference, as is the nature of genetic drift and natural selection.

BTW, we have the resources, they are just not being allocated to such 'frivolous' aims, lol.


Ortu Kan said at October 2, 2010 6:26 PM:

To illustrate the problem, depending on your definition, there can be less than ten million species on Earth to over 100 million. Endangered estimates tend to use more liberal definitions.

These delimitations suffer from arbitrariness, absolutely. Distinct binomial designations (“species” in the practical sense) have no guarantee of concordance with hybrid incompatibility or monophyly, and there’s certainly nothing like a minimum bright-line for genetic distances (or a maximum for intra-specific variability). Why? For most taxa, formal descriptions were predicated largely on morphological disparity from the most similar known forms, and the vagaries of lumping and splitting, combined with incompleteness of specimen sampling, etc., means no necessary correspondence to these other measures of integrity. Biobob has underlined the merits of the biological species concept sensu Ernst Mayr (not the only one retaining serious currency, but I won’t go into that), but you’re also right to recognize the fact that reproductive isolation recognizes units that are often at odds with patterns of phenotypic disparity, ecological function, and common intuition about “clearly different kinds.” A number of other issues were touched upon (the conundrums posed by bacteria with frequent horizontal gene transfer – and asexual forms in general; temporal nature of species) … suffice it to say that they remain contentious.

All that said, it’s incorrect to attribute the wide variance in total species estimates (derived from summations of specialists’ min/max/midline estimates for their own groups of interest) to nit-picking over how we ought to cut a pie of known size. More proximate are the undescribed forms – lineages that haven’t been graced with any formal description, that have perhaps never even been collected (and may well depart the scene without the barest of scientific recognitions).

Randall Parker said at October 2, 2010 9:08 PM:

Biobob,

The ability to hybridize in nature is not a reliable way to draw species boundaries. For example, there is at least one bird species on the US East Coast where the birds in Maine can mate with the ones in Massachusetts can mate with the ones in Rhode Island and so on at each interval down the coast. But the ones in Maine can't mate with the ones in Delaware and the ones in Connecticut can't mate with the ones in Virginia. At least that's what a visiting biologist from SUNY Stony Brook once said in a seminar I attended years ago.

So for these birds how many species are there?

Another example: sterile hybrids. If two species can produce offspring that are sterile are they separate species or not? What if most of of the offspring are sterile but a small percentage are not sterile? Separate species?

Another example: species that won't mate in nature due to genetic differences in courting rituals and attraction yet will produce viable offspring that will mate with each other. Separate species or not?

Another example: Homo sapiens and Neanderthals: They probably produced viable offspring a few tens of thousands of years ago. But they are widely regarded as separate species for compelling reasons. They evolved separately and became quite different from each other.

There's no bright line between species. At the genetic level speciation is many steps. The term species has to be defined practically. There is no one authoritative definition of species.

ASPIRANT said at October 3, 2010 2:24 AM:

We may not be losing discrete species, but we still might be losing a lot of genetic diversity that will be hard if not nearly impossible to recover. If we reduce a species to 10% of its original population, even if we subsequently repopulate it and return it to 100%, the damage will be done. Populations will be more vulnerable to disease and less adaptable in the future.

Chris T said at October 3, 2010 11:31 AM:

I accept that significant amounts of biodiversity is being lost. I just have a problem with promoting large numbers when the truth is that we have no idea what the numbers are. It's the same problem I have with a lot of climate change damage estimates; large numbers get promoted when there is very little basis in reality for them.

Biobob said at October 3, 2010 11:38 AM:

"So for these birds how many species are there?"

One. You have fallen into the human time scale issue or inaccurate conclusions by that biologist. Even if such a bird species does NOT migrate any distance at all, which is extremely unlikely, individuals seeking new territory and situational strays move in a normal curve of distance and then breed; some not far, some quite far. As long as there is enough migration of genetic material in "genetic time", it's one species, and one/a few individual(s) per period less than 25 generations is likely enough. This kind of race formation is extremely common after environmental//genetic perturbation like the last ice age. I doubt any biologist has the inclination or funding to track individual bird movements for 50 years, which is how long it would take to demonstrate with bird species with year 2 age to 1st reproduction. And any biologist would have no doubt that any persistent genetic isolation of races would result in new species formation. That's how speciation works.

If populations do NOT EVER breed in nature due to courting etc whatever then they are species since no genetic exchange occurs in nature PERIOD. I fail to see any issue whatever. If we stick nuclear material in a gamete and raise an individual, that has absolutely nothing to do with a species definition. We are perfectly capable of putting mice genes in humans and vice-versa - SO WHAT? Are you suggesting that mice and humans are not separate species as a result?

If offspring are 100% sterile then they are species, if less than 100% then NOT species; any genetic exchange between populations means there are NOT separate species. You are splitting hairs, Randall.

Neandethal and Homo sapiens breeding = speculation. Look, Randall, they may not even have gotten a reliable mDNA sample from neanderthals, the data is so bad. Let them clone one and try reproduction with H. sapiens in some way shape or form and let the chips fall where they may. There IS a dividing line between species, but it's too often the case that we humans are not bright enough to see the line, LOL.


Randall Parker said at October 3, 2010 12:22 PM:

Biobob,

There's not a single agreed on definition of species among biologists. The Species Problem has attracted countless books and articles.

As for Neanderthal mtDNA: I am told that Svante Pääbo and the people who work with him are very careful. One can tell by a variety of ways whether it is correct. For example, they got samples from 3 bones. So they had the ability to cross check. Also, some sequences are not reasonable. We are only talking about 15k letters. One can look at that small amount very carefully and compare to many other mtDNA samples from other species.

Biobob said at October 3, 2010 3:02 PM:

And who ultimately cares about and defines species? the individuals of the populations involved, of course. The problem is that the biologists are stuck playing catch-up, lol, and therefore can NOT come to a single conclusion, or can not gather the information required to draw correct conclusions (the usual problem).

Randall, I understand your difficulty with the issue but as far as the species problem is concerned, only humans have issues with these facts / definitions, not the breeding units.

IMO, even with asexual reproduction, the sad truth is 100% parthenogenetic lineages are all species in and of themselves by definition and fact; and all prokaryotes that gratuitously exchange genetic material become one species, by definition and fact.

3 whole samples of mDNA vs the entire genome !! i am totally impressed [NOT]. Get back to me when they have a statistically valid number of samples needed to come to some sort of conclusions that neanderthals were not Homo sapiens in fact, or conclusively demonstrate that the contemporaneous populations interbred or not. The major portion of the species problem results from inadequate sampling and the limits of human "knowing".

The unit of selection is the breeding individual, and the genetic unit is the entire population; all parts of the population that pass along and share that genetic material with its results of selective pressure forms a species. The species knows, but we may not. But that is how things have worked out in the billions of years history of life on earth.

We certainly can argue about the nature and definition of life, but once an organism starts down the pathway of evolution, only the concept of species and natural selection makes sense of it all. And getting back to the issue at hand, mankind is certainly considerably simplifying the issue by reducing the diversity of life on planet earth.

Chris T said at October 3, 2010 7:01 PM:

And who ultimately cares about and defines species? the individuals of the populations involved, of course.

This is a tad bizarre; the classification of life is a purely human concept and endeavor. We're the only known organism that cares.

Randall, I understand your difficulty with the issue but as far as the species problem is concerned, only humans have issues with these facts / definitions, not the breeding units.

All definitions are human constructs; if we don't agree on the definition, than there is no concrete definition.

Biobob said at October 3, 2010 7:32 PM:

Chris, you need to step back and think. Do you think evolution will stop if humans do not exist? Do you think that species will not exist without humans and that individuals, populations, and species will not evolve as the result of selection, with the lucky ones forming new species and the "unfit" ones going extinct ? Pigeonholing species into a hierarchy is certainly a human construct but it's one that attempts to reconstruct the evolutionary history of species.

Species "KNOW" the definition of species; they live it and the physical and biotic boundaries of individuals and populations which are the limits of that species. These interactions define the species, and it does not matter if humans are there to observe and define. The genetics of that species, its populations & individuals hold the definition, history and future of that species. The definition of a species is simple as previously stated and every species on earth "knows" it, except perhaps humans.

Randall Parker said at October 3, 2010 8:23 PM:

Biobob,

Whether two populations are distinct species or not what is important in the context of this blog post is loss of genetic diversity. If a subpopulation that is adapted to a particular ecological niche gets wiped out and that subpop is uniquely adapted to that niche then whether or not it is a unique species its genetic adaptations are lost.

Look at the great extinction events of the past. When Siberia erupted into a supervolcano 250 million years ago and wiped out the vast majority of existing species on land and in the oceans even after the eruptions stopped it took a long time for the amount of biomass to be restored by mutations that generated new species to fill in various niches. We probably aren't going to do so much harm to the biosphere that all life dies out. But we could so reduce the number of existing species that productivity of various areas drops substantially.

Biobob said at October 3, 2010 10:11 PM:

I have to agree with you there, Randall.

And we are only shooting ourselves in the foot when we destroy/fragment habitats, extirpate species through over harvest, etc. Evolution results in the approach to optimal energetic efficiency if frequent perturbation of habitat and biota is avoided. Until recently, we restricted our worst damage to temperate and arctic zones which have more or less evolved to deal with instability (winter/ice ages). But now we truly are the bull in the tropical china shop, lol. I suspect we will either learn and put into practice the required lessons evolution has to teach or suffer the consequences of our hubris.

It's the same old story - live within your means or go "bankrupt", spreading misery in your wake.

fmarke said at October 4, 2010 10:26 PM:

Oh please, we have no denominator so any estimate of "what's extinct" is just plain wrong.

Biobob said at October 5, 2010 4:28 AM:

fmarke,

It's actually "we have no denominator nor do we have any numerator". Yes, we have no clue cuz we are so uber !! LOL

Biobob said at October 5, 2010 4:36 AM:

Oh, and Randall, I am not all that terribly concerned long term about the diversity issue. Diversity will eventually regenerate and so will species, and likely more quickly than you think. However our loss will be immediate and, in human terms, forever, since to us 1,000 years is a long time. That value of information encoded in species DNA is priceless, and that particular "informational instance" is lost forever.

Engineer-Poet said at October 11, 2010 6:14 AM:

Diversity will regenerate, but the species which disappear can include higher primates.

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