John Blatchford's Blog

Posted by John Blatchford

The Common Cuckoo (Cuculus canorus) is having a hard time in England, with only an estimated ten to twenty thousand pairs left in the year 2000 – about a 60% drop since the 1960’s.

The cause might a reduction in insect numbers, either as suitable insect food for the cuckoos, or as food for the Dunnocks, Meadow Pipits, and Reed Warblers that cuckoos usually choose as hosts (cuckoos are brood parasites – laying their eggs in the nests of other birds).

Whatever the reason for the worrying crash in the cuckoo population, it is almost certainly due to human activities.

Creationism and Evolutionists

Creationists would probably see the Common Cuckoo as a bird specially created for life in England, while those who believe in evolution by natural selection would understand it as a species that has evolved over time to fill a niche in the English countryside.

Human Activities and Species Decline

Maybe creationists would see human beings as having every right to influence their environment in a way that is detrimental to other creatures, and maybe evolutionists would see human beings as just one more species – one capable of influencing the distribution (and in many cases survival) of other others. But surely the real issue is that mankind is impoverishing the natural environment – whichever view is held.

Our grandchildren, or their children, might well grow up in a land where the cuckoo rarely heralds the English spring, and they will certainly see fewer wild species than our parents and grandparents.

In my own view this is something to be taken very seriously indeed. While it can be argued that humans have always exerted a similar effect on their immediate environment, that environment now spans the globe. Pollution is worldwide, habitats are being destroyed at an ever-increasing rate, and climates are changing.

• If all life was created specially, then we are systematically destroying a large part of it.

• If all living things evolved gradually over time, then we are changing the environment too fast for most species to adapt.

Mass extinction due to human activities is very close, and – however the living world came to be – there is little time to address the problem. The creationist/evolutionist debate pales into insignificance in the face of this crisis.

Posted by John Blatchford

Habitat loss is bringing many species close to extinction. Urban and industrial development, pollution, and climate change all play their part, and often the combination of effects is greater than predicted.

Some of my recent articles look at specific cases to show how this all works.

Royal Society Lecture 2009

The coral reef crisis shows the enormous effects that increasing levels of atmospheric carbon dioxide can have on the marine environment. ('Coralline algae' looks in a bit more detail at what might happen soon.)

The full report can be downloaded as a pdf and read at leisure – it makes scary reading!

The talk Professor John Veron gave to the Royal Society is also available as a webcast – ‘Is the Great Barrier Reef on deathrow?’.

Carbon dioxide enters the oceans through the recently discovered ocean surface film, and the implications of this on water acidification are not yet understood.

Urban Development

The wild axolotl is close to extinction, largely due to the fact that its only habitat is now surrounded by Mexico City. It could easily be reintroduced from captive stocks, but this might not be a good idea (explained in ‘Reintroducing endangered species often dangerous’).

Loss of mangrove forests worldwide is another serious problem, and selecting a suitable ‘flagship species’ is suggested (in this case the Proboscis Monkey).

Illegal logging is responsible for loss of forest habitats, and it is an ironic fact that many newly discovered rainforest species are endangered the moment they are discovered. My Kipunji article looks at this in a bit more detail.

Climate Change

Increasing temperatures affect the distribution of many creatures, and sometimes seemingly trivial changes can have surprising effects. The relationship between an ant and the Large Blue butterfly show one such unexpected consequence. See also my article about the effects of climate change in the arctic tundra.

Synergies

Very often it is difficult to point to any single factor that is causing habitat loss or endangering a species. This is because the accumulation of many small changes can add up to a crisis – the small stresses work together ‘synergistically’. In other words the combined effect is greater than would be expected from simply adding all the small effects together.

This is very well explained in the document produced by the working party studying the coral reef crisis. It is essential reading – download it!

Posted by John Blatchford

Complex ecosystems have evolved over long periods ot time, and while concentrating on particualr 'flagship species' to help conserve them is useful, it is essential that their full complexity is understood if they are to remain intact.

Flagship Species

A single animal (or plant) species, usually rare and charismatic in some way, is often chosen to ‘front’ conservation efforts to save habitats and ecosystems.

The Giant Panda focuses attention on preserving China’s wild mountain bamboo ecosystems – but people ‘miss the point’ if they think that keeping a lot of pandas alive and well in zoos addresses the same issue (unless habitat restoration and eventual liberation back into the wild is the plan).

Preserving a threatened habitat will help the entire ecosystem, and in this way the well-known flagship species will thrive – indicating the success of the venture.

Complexity of Ecosystems

There is always ‘more than meets the eye’ to an ecosystem. Take the case of the red ants necessary for the survival of the Large Blue Butterfly as an example. Heath grassland, which looks good to human eyes, might be just a little bit too long (due to a decline in grazing by rabbits and sheep) for one particular species of red ant upon which the butterfly depends for survival. Understand this and management is possible – ignore it and a nice-looking, but impoverished, ecosystem will be produced.

Global Warming

As climates change around the world many species are extending their range. The European Carpenter Bee, for example, now seems to be moving north into Britain. Surely this means that many stable ecosystems are being invaded by, what are (in effect) ‘invasive species’.

Habitats have always been changing, and ecosystems adapting to the changes – but human effects (of habitat destruction and global warming) are forcing change at an unprecedented rate.

Posted by John Blatchford

Taxonomists give strange animals their own group until evidence of relationships is found.

When a new animal is discovered it is usually possible to see where it fits in the ‘tree of life’, but occasionally something weird turns up. Taxonomists (people who decide how to classify living things) often use body plans to decide how animals are related, and when something novel, or very simple, is found, it is sometimes given its own phylum. Further research (often molecular studies) usually either confirms the novelty, or suggests unforeseen relatives.

Echiura or Spoon Worms

The Spoon Worms were originally give their own phylum (Echiura), but evidence from studies of their DNA suggests that they are related to the annelids and modern practice is to include them in the phylum Annelida.

Entoprocts or Goblet Worms

The Goblet Worms are still problematic – some consider them to be a kind of bryozoan (ectoproct). Others consider the fact that the exit from their alimentary canal is located within the ring of their cilia (as opposed to the ectoprocts, where it is outside the ring) is sufficient to show that these animals are not closely related.

Acoelomorpha

Very simple creatures that look like small blobs! They are so simple that they all look alike – there may be one species or hundreds. Even so, many taxonomists think they are probably a type of highly simplified flatworm (phylum Platyhelminthes).

Taxonomy (how things are classified) reflects the evidence available, and how different specialists interpret it. Some prefer to ‘lump’ all sorts of animals together whenever there is a whiff of kinship (the ‘Lumpers’), while others keep them in separate groups until there is overwhelming evidence of relationships (the ‘Splitters’).

Posted by John Blatchford

Annelids are the ‘True Worms’, and most are long thin and wiggly and the nematodes (or ‘Round Worms’) look similar. Many other phyla share this body shape and are called ‘worms’ of one type or another.

• Flatworms are mostly parasitic, and as the name suggests are typically flat rather than round. Horsehair Worms are also parasites, as are the Spiny-headed Worms, and these two phyla are capable of modifying their host’s behaviour (see ‘Horsehair Snakes’ ) – sometimes called ‘brain jacking’.

• Most ‘Arrow Worms’ are active predators in the plankton, swimming efficiently and capturing small animals with their hunting spines that act like teeth, and most ‘Ribbonworms’ hunt on the sea bed.

• All the other ‘worms’ (jaw worms, acorn worms, horseshoe worms, rude worms, and peanut worms) either scrape food or filter feed.

There are hundreds of thousands of species of animals called ‘worms’, but all the different phyla have in common is the body shape. With the exception of the earthworms (annelids that most people will have seen) these phyla are unfamiliar to all but specialists, and the details of their evolutionary relationships with one-another are not at all clear. Their soft bodies rarely leave fossil evidence, and it will be necessary to study molecular details (DNA in particular) to clarify these matters.

Posted by John Blatchford

A Fruit Bat settled on the fuel tank of Discovery just before the launch into space on 15 March 2009. Maybe the poor creature was trying to prove that bats are every bit as tough as Water Bears (Tardigrades), but he missed the point! The tardigrades were inside the spaceship until they reached their destination, and furthermore they were already in suspended animation. It appears that the bat simply became a bit more ‘space debris’.

Water Bears Crawling

Tardigrades move relatively slowly (watch YouTube video), unless, of course, they are being sent into space! There is not much need to move fast when you spend your whole life ambling between grains of sand. Presumably this way of life also determines the size of Water Bears (they are usually less than a millimetre long), and keeps them reasonably short.

Fossil Tardigrades

My blog about Beorn leggi describes the rather whimsical naming of the first fossil specimen ever found – but does not even begin to tackle the question of ‘how does an animal that usually lives in the sea between sand grains get trapped half-way up a tree in resin?’. If any reader can enlighten me with a comment about this I would be grateful!

Bats and Moles

I had not intended to write any articles about mammals for a while, having decided that my first articles in the ‘Zoology’ section would cover a few of the less well-known animal phyla. In my first four articles I stuck to this plan, but then I got side-tracked into writing about Chordates and the evolution of the vertebrates and modern scientific classification.

I just couldn’t resist mentioning the bat that tried to get into space – and a few recent questions (from my wife about how moles breathe when they are underground burrowing away feverishly) tempts me to try to answer with an article about mole adaptations. Before that, or alongside that, I will try to stick to my original plan for a bit longer. Maybe ‘Velvet Worms’ (Onychophora) next – unless any reader has a specific request.

Posted by John Blatchford

The first fossil tardigrade was named after a character in one of J. R. R. Tolkien’s books.

Fossil in Amber

Beorn was a ‘skinshifter’ who could turn from human form into a bear. Kenneth W. Cooper found the first fossil tardigrade in amber from western Canada (Journal of Entomology 1964), and used Tolkien’s mythical creature’s name for the genus. The specific name (leggi) was chosen for one of Cooper’s students (William M. Legg) – although personally I wonder if he was also alluding to the eight stumpy legs!

Discovery of Tardigrades

Goeze (in 1773) was the first to describe a living Water Bear, although some people think that Anton van Leeuwenhoek was actually the first to see them. Leeuwenhoek took some dried dust and added distilled water – things came to life! (This sounds very much like tardigrades to me.)

DNA and RNA Studies

• Modern research (looking at sequences of DNA) suggests that the tardigrades are closely related to the arthropods, and also to a ‘sister phylum’ the Onychophora. This seems to fit well with the way they look – all are segmented, and the stumpy little legs look remarkably like those of the Onychophora and the ‘prolegs’ of caterpillars.

• Things get more confusing when RNA is studied – this seems to suggest that the tardigrades also share a relationship with the nematodes (roundworms), and not the annelids (segmented worms) as previously thought. It is true that the mouthparts of tardigrades are a bit ‘nematode-like’, but the fact that they are segmented makes them look like annelid allies. Further research is needed.

Family Trees

Modern animal classification tries to group animals in a way that shows evolutionary relationships, and it relies more and more on molecular research. Many zoologists are now pointing out that ‘lateral DNA and RNA transfer between species’ is known to occur on occasion (regularly in bacteria, and occasionally when a virus moves from one species to another) – and they urge caution when using molecular similarities to infer evolutionary relationships. Some have gone so far as to suggest that we should stop thinking in a ‘tree-like’ way and imagine ‘webs’ of relationships. (See ‘Mesozoan Orthonectids and Rhombozoans’ , which adds to this debate.)

Posted by John Blatchford

My first articles as Feature Writer for ‘Zoology’ look at four of the least known animal phyla. I intend to continue this theme for a while, exploring some of the other weird beasts that few people have ever heard of – let alone seen.

Minor Phyla and Evolution

While the animals covered in these articles will rarely be of major significance to most people, they all help illustrate the challenges of classification and the way that our understanding of evolution is being deepened by research in molecular biology and genetics. Where possible I point to recent research and hint at where things might be going.

• Trichoplax adhaerans shows how a very simple body-plan might hide a complex ancestry.

• Symbion species show how very similar-looking animals might be very different from one-another when they are studied at the molecular level.

• Loriciferans open up the whole new world of ‘life between the sand grains’ and hint that many new phyla are probably waiting to be discovered (new species turn up here every day!).

• Horsehair Snakes are also pretty strange, and, while little is known about their genetics, the study of the way that these parasitic animals are able to influence the behaviour of their hosts is of potential value where human parasitic diseases are concerned.

Future Articles

I plan to write a few more articles about these unusual animal groups before moving on to some of the better-known ones, and, as usual, I would welcome any comments you might have. If you find any group of animal particularly fascinating then let me know, and I will put it on my todo list.

Posted by John Blatchford

All animal life will be here - eventually!

New to Zoology

I have just become the Feature Writer for Zoology, and have posted my first article as such: ‘The simplest animal on the planet’.

What I Intend to Write

I have written many articles in the past (in other sections of Suite101), which could easily have been put in ‘Zoology’, but here I am starting from scratch. I intend to spend a few of the early weeks looking at some of the simplest of animals – those that are least familiar to the general public. In doing so I will highlight recent research, and maybe show just how fascinating some of them are.

Section Image

I chose a picture of a barnacle as my section image, partly because they have always fascinated me, and partly because they were also very important to Charles Darwin – the founder of modern zoology. I hope to show how recent work has built on his ideas and now lets us see how many are related (in an evolutionary sense).

Past Articles

If you are interested in zoology, but find my articles here a little ‘thin on the ground’ you might like to browse through a list of all my previous stuff - there are a lot about the various whale species and their evolution, and some about a number of other weird and wonderful creatures.

Comment and Criticism

As always I welcome comments and criticism – so just sign in and say what you think.

Posted by John Blatchford

In an attempt to engage more members of the general public (i.e. not only the specialists and ‘nerds’ referred to in my last blog) I have decided to write about important exhibitions, particular species, habitats and environmental problems found in some of the better known tourist locations around the world.

Here are five recent examples:

• Tempting Readers to Find Out About the Darwin Exhibition

I used the famous Marine Iguanas of the Galapagos Islands to try to get more people to look at what is on offer at the Natural History Museum in London this year.

• Engaging Readers with Climate Change

The attractions of Venice and the controversial Mose Project seemed a good way to get people thinking about Climate Change issues and Global Warming.

• Making the Link Between Pollution and Health

Taking recent scares about the safety of some French oysters seemed a good way to suggest the important link between our pollution of the environment and the potential health risks we are exposing ourselves to.

• Eating Intelligent Animals

Looking at the octopus and indicating how intelligent it is thought to be raises ethical questions about what we eat. I like grilled octopus – but maybe it is wrong to catch, kill and eat sentient beings?

• Flagship Species and Conservation

I use the Seychelles, and particularly Aldabra Atoll, to show how one ‘flagship species’ (in this case the Aldabra Giant Tortoise) can be used to publicise conservation efforts which preserve entire ecosystems. A similar article could have been written about Giant Pandas, Mountain Gorillas, Polar bears, Blue Whales etc. etc. – but I chose the tortoises because of the link with a well-known tourist destination.

Search Engines

These five recent articles are an experiment to see how much the reference to holiday resorts and tourist destinations influences the number of readers finding my articles through search engines. The hope is that members of the general public might ‘stumble upon’ these articles while idly browsing their vacation plans, and that having found them they might actually read a bit and think about the issues!

Posted by John Blatchford

How can I write about complex issues for a number of different audiences at the same time? It is crucial to get the science right – but what beyond that?

Writing for Specialists

They know already, and if they do happen to read one of my articles it is probably only to check that I have ‘got it right’. If they are kind enough they will correct any errors (with an email or as a comment on the article) – or they might add a ‘dimension’ that I did not cover (as happened with the first comment on 'Venice Italy Mose Project and the Lagoon').

Writing for Nerds

I heard an interesting piece on the radio this morning. It pointed out that many people (among the ‘general public’) hold jobs unrelated to their academic training (maybe a political figure who was initially trained as a geneticist). These were called ‘nerds’ in the program, and it pointed out that there is no need to simplify the science for this cohort – indeed it would insult their intelligence. Again, for these people it is important to ‘get things right’, but here it is also useful to point towards unmentioned complexities with phrases like ‘further work on DNA analysis is helping to resolve this problem’ - to show that I am aware that what I am saying represents an older point of view, and know that things are changing.

Writing for the Scientifically Illiterate

Many of the general public (maybe the majority?) have little or no scientific training, and this poses the greatest challenge – how to encapsulate the salient points in a brief article without assuming specialist knowledge. For these readers I try to add hyperlinks to websites which themselves lead further into the subject.

Help from Readers

I am trying to reach all three groups with my articles in ‘Marine Biology and Oceanography’, and I would be grateful for any comments from readers about how I might do this better.

Posted by John Blatchford

If you build a city at sea level you must expect to get wet from time to time!

Venice Flooding in 2005 and 2008

Venice has always experienced occasional floods, but serious inundations are now a regular phenomenon (watch one video of the flood in 2005, and another from 2008). Things are getting steadily worse, and if the city is to be saved the waters must be kept at bay.

Mose Project Dams to Stop Flooding

Enormous structures are being built on the seabed at the three points where water enters the lagoon from the Adriatic Sea (watch a video – in Italian – which shows details of mose the project). The barrier will rest on the sea floor until needed, then rise up to hold back the water when sea-level gets to a dangerous level. Ships will still be able to gain access to and from the lagoon through locks, and the flow of seawater will only be interrupted occasionally (the flow of water through the lagoon is essential for removing pollutants).

Financial and Ecological Costs of the Mose Project

Huge structures come at a huge cost. Some oppose the Mose (Modulo Sperimentale Elettromeccanico) project on purely financial grounds, while others point out that any interference with the natural flushing of the lagoon will lead to problems. Venice is an industrial centre, with all the associated pollution problems, as well as a World Class tourist attraction. Some worry about mercury levels, others about zinc (see ‘Venice Italy Mose Project and the Lagoon’) – while yet others point out that Venice has no sewage treatment and relies on the flow of water to keep the canals clean. Watch a video (again in Italian) which summarises the causes of concern.

Read also a ‘Times Online’ summary of the situation from 2007

Posted by John Blatchford

I thought I should write a 'big' article for my 200th - so I have tried a brief history of life in the oceans.

Earth History in 400 Words

Of course this is an impossible task! - so I limited myself to the briefest of sketches and only mentioned the major events. Anyway, I suppose that any more detailed review of past life in the sea would rightfully come under 'palaentology' and not 'marine biology.

The only three links that I used were to coelacanths, marine reptiles, and marine mammals - I did not even mention the birds (penguins) due to lack of space.

It would have been interesting to talk a bit more about the nature of the five mass extinctions: how asteroid impacts, global warming and global cooling have all played their part. There just was not space.

The Early Fossils

Among the most enigmatic of the early multicellular marine animals are the 'ediacarans' - strange experiments in the manufacture of a complex animal. These were all wiped out, so I left them alone!

Modern Oceans

I suppose that most of my writing on Suite101 (as FW for Marine Biology and Oceanography) is about life in the sea in modern times, so all I did in this article was to point out the damage humans are doing. (This is a common theme through most of my articles, where I try to spell out exactly what the problems are.)

Darwin 200

Charles Darwin was born 200 years ago. He gave us an explanation of evolutionary change over time, in a way that was accessible to the literate public of his time. His views changed the world, and it can be argued that he created modern biology. It is ironic that 150 years after he descibed so many creatures, and suggested how they might have evolved, we are busy wiping them out!