Survival of the fittest must mean that some species will inevitably fail. So isn’t this something we should just accept? I love pandas, but will it really matter on a global scale if we don’t have them any more? We seem to be surviving ok without the dinosaurs.
This is a question that could cause a very long debate - it seems a simple question, but the issues involved are not!
First the science - yes, we know from the fossil record that extinction happens naturally - there have been several mass extinctions in the last 4 billion years in which huge numbers of species in existence at those times vanished. Natural selection explains how evolution happens - and why some individuals, population and species thrive and avoid extinction.
But does it matter? That's not really a scientific question, but is based on human values and interests.
From a practical point of view, we know that we need ecosystems to survive - we rely on them for food, natural resources and all sorts of other things. The Millennium Ecosystem Assessment dealt thoroughly with these issues. If there are changes to the sizes of populations or the number of species as a result of our activities, ecosystems change, and the services that they provide to us will also change - and we may suffer as a result - sometimes financially, sometimes in other ways. Sometimes changes are so gradual that future generations will suffer - we can see this to some extent with climate change.
The disappearance of one species from an ecosystem may not be noticed, or may not have an immediate apparent effect. However, there has been a lot of concern on numbers of pollinating insects in recent years - reductions in numbers leads to lower crop yields. This is not extinction as such, but complete disappearance of some pollinating insects would have a bigger effect. And it could lead to a knock-on effect - we would see problems with crops, but wild plants would also be affected, with potential effects on other insects and birds.
But our practical needs, or those of other species, are not the only issue. You love pandas - and it would matter to you if they disappear. And this is a serious point, because you can see that the way in which people feel about these issues changes policy - it might be their personal feelings, or might be a moral issue to some. The history of nature conservation in the UK and elsewhere is often about the decision of groups of people - the wildlife trusts, for example, or various bird conservation charities - that they want to protect various species or places because they matter to them.
Having said this, what matters to one person may be a difficult choice for another - and where people are poor, they may feel a need to grow food or make money to stay alive even when this means the gradual and inintended destruction of habitats. Similarly for those of us in richer countries - we may make choices about consumption or lifestyle that, unintentionally or otherwise, do not take account of impacts on biodiversity in other places, now or in the future. So conserving biodiversity must be seen in a wider context of economics, development and politics, persuasion, collaboration and incentives - conserving biodiversity is essential, but not simple.
Don't forget, the dinosaurs died from a natural cause, so you could say it was 'meant to be'. We have to think about the number of species going extinct NOT because of natural selection, but because of our actions - sport hunting and poaching, CO2 pumped into the atmosphere and fossil fuels dug up from underground, and habitat destruction, for example. These activities are putting extra pressure on species to have to adapt quickly to the changes or die out.
Now you could also say that it is 'natural and meant to be' that we have evolved this far and are doing these things so it doesnt matter if it continues. Well, I would like to think that our highly evolved moral conscious would make us stop, take a look at what we are doing and stop for the sake of biodiversity that would otherwise not be as threatened and would be thriving, and natural selection alone would dictate what goes extinct and when.
Let us assume that we could kill the mosquito vectors of malaria. It would of course be easier to kill all mosquitoes (and every time one is bitten the temptation springs to mind). However, what might be the impact? Mosquito larvae feed on bacteria and algae, so we might expect increased growth of both in water without the mozzies. The larvae also are food for fish and other predatory aquatic animals, like dragonfly larvae, water beetles, other aquatic fly larvae, water bugs and copepods. They might be particularly important in small ecosystems like tree-holes and some plant reservoirs like bromeliads. The adults are food for birds, bats, dragonflies, spiders etc. So, if we removed mosquitoes from the system, we impact on a lot of other species as well, and predicting what that impact might be is probably beyond us right now. It is a good question, of course – in the long term (and the short term, come to that) in the only way species (and ecosystems) are going to survive is if we make a decision about each one, rather than just let things happen.
Fairydance's original post and the reply address a very difficult set of questions. Humanity is actively trying to drive a few disease-causing organisms to extinction for justified reasons.
There are some global programmes to make some organisms completely extinct (eradication), but as yet smallpox, a virus, is the only one where this seems to have been achieved. Others, such as polio, are meeting with some degrees of success. Smallpox and polio are transmitted between humans, and vaccination has been the key factor in successful control. Achieving this is expensive (in terms of total cost, if not individual) and difficult, but achieves great benefits in terms of human life and well-being, and no direct biodiversity impact beyond the particular pathogen.
In terms of public ethics in healthcare, this approach is justified - we remove a cause of significant harm (and death) to many individual people: the disappearance of these particular species is accceptable. There is going to be discussion on the ethics of where you put healthcare resources, but the disappearance of the pathogen species is going to be effectively uncontroversial. There might be reasons to keep small stocks of the pathogen alive - but this again is justified by direct human interest in medicine.
Malaria is more complex. There are discussions going on about eradicating the disease, which kills almost one million people each year, most of them small children. The focus is on eradicating a few species of the parasite Plasmodium, which are carried by some mosquito species.
Those of us living in the UK, Europe and the eastern US are not threatened by malaria because of past control and ongoing monitoring - a combination of the use of quinine to remove the Plasmodium in humans, draining marshes and, for some countries where it persisted after the second World War, use of DDT in huge quantities to remove the mosquitoes broke the cycle of transmission. Use of the pesticides had big effects on biodiversity, as Pipers says, but there was a lot of agricultural use of those pesticides at that time that would make it difficult to assess the real impact. There are Anopheles species in the UK, but the last proper malaria outbreak was many decades ago. There is more concern on West Nile Virus - a recent interesting report looks at the picture for London.
For the rest of the world the approach has moved on to much more focused intervention where possible - wiping out mosquitoes has proved almost impossible for practical and financial reasons, in addition to the side effects on biodiversity. The emphasis is on a mixture of local control of mosquitoes in human habitats - so low-level use of DDT in houses, and pesticide-impregnated nets - with the use of effective drug treatement. Also there is talk of a vaccine, with quite a lot of research but no effective clinical product yet. The scale of deaths and wider morbidity shows that we have a long way to go.
Additional interest on the origins of malaria in humans - Plasmodium falciparum has the most serious impacts, and a paper in Nature yesterday suggests that it is a parasite that has made the jump from Gorillas to humans in the distant past. The news commentary in Nature is easiest to read - Nature Volume:467, Pages: 404–405 Date published:(23 September 2010) DOI:doi:10.1038/467404a
Why is this of interest? Shows that some human diseases need to be understood, and controlled, with good understanding of wider biodiversity patterns - a species that we protect - the Gorilla - is closely linked with other organisms that we are not so keen on - Plasmodium. It is known that new species and strains of malaria appear in particular people from time to time - again from other animal hosts
Great question bluebird. We think it really does matter when plant species go extinct. Here's why...
Today, 60,000 to 100,000 species of plant are faced with the threat of extinction. We need plants, because plants are useful. Plants provide the air we breathe, they provide clean water, fuel, building materials, fibres, resins and we all rely on plants for food and medicine too. Plants also play a vital role in combating climate change. They maintain the atmosphere and counteract climate change by absorbing carbon dioxide, turning it into plant material.
We already know of thousands of plants that are useful to people, but many more have the potential to be useful in the future. Over 30,000 species of plant are edible, but we use only a tiny fraction of these in commercial agriculture. In the future we may well need a much greater range of species, particularly if climate change alters growing seasons or the world’s population continues to increase and we run out of prime agricultural land. Plants are also vital for medicine. About 70% of the world’s population relies on traditional plant remedies for medicine. Only one in five plant species have been screened for use in medicine. Cures for diseases could lie in many of these unscreened plant species.
We can't afford to let these plants, and the potential they hold, die out. Plants are dying out largely due to the activities of people. Clearing of primary vegetation, over-exploitation and climate change are all causing species losses.
By 2020, Kew's Millennium Seed Bank aims to secure the safe storage of seed from 25% of the world’s plants. We target plants and regions most at risk from climate change and the ever-increasing impact of human activities. We also save the seeds of the world's plant life faced with the threat of extinction, and those that could be of most use in the future.
Check out our Adopt a Seed, Save a Species campaign to find out how you can get involved - http://www.kew.org/support-kew/adopt-a-seed/index.htm
A global analysis of extinction risk for the world's plants, recently conducted by Kew together with the Natural History Museum, London and the International Union for 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, entitled Sampled Red List Index for Plants, 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. Below is a list of information and resources on Kew's website that you might find useful.
Explore plants at risk using Kew's interactive maps and graphs
Plant groups and example species
Five major groups of plants were included in the IUCN Sampled Red List Index for Plants. It is possible to say for the first time which plants are more threatened, where and why. Find out more about each group and the threat level facing them here.
We hope this helps.
I think that it is up to you say it was your favourite animal then you would be devastated, right? But if it was an animal that you didn't really like then you wouldn't be so bothered. So I think it is entirely up to you.
Hope you find this information useful, bluebird,