Tuesday, 29 May 2007

Around The World Today

To many weird stories to blog about today so here are some links:

Poland inquiry to probe 'gay' teletubbies
Poland's conservative government sees the teletubbies as homosexual propaganda on the small screen, and is taking aim at Tinky Winky and his friends. Ewa Sowinska, government-appointed children rights watchdog, told a local magazine published on Monday she was concerned the popular BBC children's show promoted homosexuality.

Bonnethead Sharks and Komodo Dragons reproduce without sex
Sex is not necessary for all members of the animal kingdom. Of course it has its advantages, primarily, combining genetic material adds to the diversity of a species and makes it more ‘hardy’. But in vertebrates, organisms that are considered ‘more complex’ (ie. fish, amphibians, reptiles, birds and mammals) asexual reproductions is extremely rare and is thought to be limited because of the complexity of vertebrate genetics and body plans.

New Zealand cows produce skimmed milk
Experts at a biotechnology company in New Zealand have discovered that some cows have a gene giving them a natural ability to produce skimmed milk. The finding could be used to develop a dairy herd that produces low-fat milk. A cow with the "skimmed milk" gene was identified in 2001, and the team have since been able to breed calves that also produce the low-fat variety.

Outcry over TV kidney competition
The show comes from Big Brother creators Endemol. A Dutch TV station says it will go ahead with a programme in which a terminally ill woman selects one of three patients to receive her kidneys. Political parties have called for The Big Donor Show to be scrapped, but broadcaster BNN says it will highlight the country's shortage of organ donors.

Monday, 28 May 2007

Spiders on Drugs: Part 2

Some of you may recall the 'Hinterland Who's Who' parody that I posted back in March about spiders on drugs. Well Shelley Batts of Retrospectacle actually found an article on the effects of psychoactive drugs on the web-building activities of spiders published in NASA Tech Brief. Click on the image below to enlarge it and see the crazy webs stoned spiders make.

And in case you missed the HWW parody, here it is:

Friday, 25 May 2007

Snake explodes after swallowing alligator

Thanks to Janine for pointing out this story of a python which burst open after gobbling up a Florida gator.

The strange scene was found by park rangers in the Everglades National Park. The Burmese python is likely an escaped pet or perhaps a descendant of one. In recent years many guilt-ridden owners release their exotic pets into the hot and wet swampy environment because they are no longer able to take care of them and do not want them put down.

Because pythons are not natural to the environment, the rangers suspect that they challenge the alligators' position as apex predators in the food chain. Frank Mazzotti, a University of Florida wildlife professor, says "Encounters like that are almost never seen in the wild. They were probably evenly matched in size. If the python got a good grip on the alligator before the alligator got a good grip on him, he could win." He also suggested that the alligator may have clawed at the python's stomach, leading it to burst.

This is not the first encounter between the two giant reptiles, at least three other similar incidents have been recorded in the past.

The picture (click to enlarge) depicts a 2m long alligator partially swallowed by 4m long python, whose belly ruptured during the process. The victim's tail and hindlimbs are protruding from the predator’s burst abdomen. The head of the python was missing, perhaps due to scavenging by other wildlife.

Thursday, 24 May 2007

Fossil tracks suggest dinosaurs could swim

Ancient footprints have provided compelling evidence that some dinosaurs were able to swim. The 15m (50ft) trackway was discovered in the Cameros Basin in Spain, which, 125 million years ago, in the Early Cretaceous was a vast lake.

The unusual-shaped prints suggest the animal clawed at sediment on the lake bottom as it swam in about 3m (10ft) of water. Though it has been suggested that large sauropods occasionally waded through shallow waters, it is thought that these tracks were left by a large, bipedal, carnivorous dinosaur that was not wading, but rather was using the water to support its body.

Dr Loic Costeur, a palaeontologist at the University of Nantes, France, says "The Cameros Basin has thousands of walking footprints from diverse dinosaur fauna, but when we saw these it was obvious straightaway that this was a swimming dinosaur."

The underwater trackway is well-preserved in sandstone and is made up of 12 consecutive prints each consisting of two to three scratch marks. Ripple marks around the track suggest the dinosaur was swimming against a current, attempting to keep a straight path. Dr Costeur also stated that "The dinosaur swam with alternating movements of the two hind limbs: a pelvic paddle swimming motion."

I guess it was a sort of a prehistoric doggie paddle:)

Lion vs. Buffalo vs. Croc

Check out this amazing video: a lionesses snags a water buffalo calf but ends up having to fight over it when a hungry croc decides he wants his piece.

Tuesday, 22 May 2007

A story about a polydactyl cat

Well, I have caught a bad cold and been stuck in bed for almost a week. So since I haven't been able to blog much, I thought I would take advantage of Benj Arriola's comment about a polydactyl cat he had when he was young, left in response to my blog about the evolution of five fingers and toes. Benj Arriola writes Global Warming Awareness and off-handedly mentioned that his comment was good enough as a blog post, I agree so I hope you don’t mind me stealing your writing, Benj :)

Benj Arriola writes…
I'm back and was searching about the ostrich people, and found it on Wikipedia. And in my search for photos, I also found this site with a page on polydactyl cats. I remember my own cat having an extra useless "thumb." Useless because they were like dead and was just hanging there. But I think that cat was a real genetic disorder in many ways, since one paw had an extra "thumb." The other paw had two nails on one digit. The cat was pure white that his eyes were very noticeable. One was blue and the other was green.

But just a background on it... when it was still a kitten, it was a stray kitten that took a ride in our car, that seemed to climb under the car and ended it's way near an area near the car battery and was securely there until we got home from a bowling trip that was just about 1 kilometer away. He was kitten although he was big enough not to depend on his mother. For me he was the best cat I had. I had cats since 1978 up to today.

When ever we go back to the bowling alley we kept going to... I noticed by the side of the building, is a big trash can and some trash dumps near it where several stay cats go to. I am not surprised if my cat's mother was probably one of them feeding on all these trash while she was pregnant.

WOW! Is this the longest comment I made in history? Hahaha. This is good enough as a blog post. Haha. Well I guess there is no other place to share it but here.

Monday, 14 May 2007

Sarda sarda

This morning my friend John Orcutt sent me this great picture of a boat he and his Dad spotted while wine-touring along the Oregon coast.

Seeing my name always catches my attention because it is so unusual (on account of my Dad misspelling it on my birth certificate). However the boat is probably not named after me but rather Sarda sarda, a species of fish that is commonly called the Atlantic Bonito. It is my understanding that this fish received its name from the island of Sardinia around which it was caught but these days it is more commonly caught by commercial fishermen around New York's coast.

Sarda sarda is often used in cuisine, especially in Japanese food. It has a cosmopolitan distribution though the globe and to my knowledge is not currently threatened or endangered by overfishing.

Thursday, 10 May 2007

Complete Book of Life from Aardvarks to Zorilla

The Encyclopedia of Life project will detail 1.8 million known plant and animal species in the format of an online archive. Each species will have its own page with descriptions, photographs, videos, and maps, compiled by experts.

It is hoped that the $100m USD (£50m GBP) archive will be complete in 10 years and that in addition to an educational tool, the archive will have value for conservation efforts.

The project will begin by harvesting information from existing databases, such as FishBase, which contains details of 29,900 extant fish species. Data input will begin with animals, then plants, fungi and microbes last. It is not clear when fossil species will be added.

Encyclopedia of Life began development January 2006 and is reminiscent of other ventures such as the Tree of Life, Catalogue of Life and Consortium for the Barcode of Life. The last was launched in 2005 and is attempting to identify all species through unique genetic markers (called ‘barcodes’) found in the mitochondria of cells. This project has so far identified more than 27,000 species.

Proponents claim the Encyclopedia of Life will be much more through and flexible in regards to structure compared to its predecessors and will include dynamic features such as live searches. Fast internet technology has meant that such a large-scale endeavor has only recently become possible.

It is unknown how many species currently live on our planet but estimate range form a modest 2 million to 100 million.

Wednesday, 9 May 2007

Life on Land: The evolution of five fingers and toes

Well it didn’t take long for avid readers to spot the oddity in Friday’s posted picture of the early tetrapod, Acanthostega. This strange animal did not have the ‘usual’ number of digits, instead it had eight. Having more than five fingers or toes is called polydactyly and is a rare condition.

Few examples of polydactyly occur in the animal kingdom today, the panda’s thumb though, is one classic example. The panda has five digits on its paw plus an opposable 'thumb' but this thumb is not a sixth digit like the others, but actually an unusual outgrowth of a wrist bone. Thus even the panda’s thumb is not truly an example of more than five digits.

So what about Acanthostega and his buddies? The Late Devonian was a busy time, plant life was diversifying and insect life was gaining ground on land. Tetrapods, were making their first steps on to land and living semi-aquatic lifestyles about 375 million years ago. These animals had many characteristics advantageous to aquatic life, such as streamlined bodies, webbed feet and tail fins. But they also had weight-bearing limbs with which they could lift themselves out of the water. Acanthostega had eight digits on its front and hind limbs and two other early tetrapods, Ichthyostega and Tulerpeton, also had more than five digits.

So how could these animals have had such a wide variety of limb structures when all of their descendants seem to have a variation upon the five digit structure? It is thought that pentadactyly evolved in an animal that was ancestral to all present day tetrapods (amphibians, reptiles, birds and mammals) and that this event event happened 340 million years ago in the Lower Carboniferous (about 35 million years after the first tetrapods evolved).

To be honest, we don#t understand how these animals could have been so experimental while their descendants were so conventional. And why 5 anyway? No one knows. And we have no examples to examine. There are few animals who have extra digits. The most common is the novelty polydactyl cat, but this species is the result of selective breeding of animals with a genetic anomaly.

In a general sense, we know that it easier to ‘lose’ a trait then to gain it, hence the large number of animals who have reduced digits. But the striking lack of polydactyl examples in the long history of tetrapods since the Devonian implies there may be an evolutionary constraint at work. For example, pleiotropy is the multiple effects of genes on more than one physical characteristic. Hand-Foot-Genital syndrome illustrates such a condition. This rare disorder malforms limbs and the urinary system because the same defective genes pattern both systems. So perhaps the constraint on tetrapod limb structure is part of a greater pattern.

Tuesday, 8 May 2007

Sorry I have been absent....

Sorry I have taken so long to add my Palaeozoic post but it will be up sometime tomorrow. Thanks for your enthusiastic responses to my Friday post.

BTW I have been posting some of my old posts on the Scientific Blogging website, which you should definitely check out. One of my posts, unfortunately not one of my more intelligent pieces, on T. rex eating coconuts was posted to Digg and racked up a whopping 35,000 hits. Fame and fortune may yet be mine, I just hope it doesn't go to my head!

Friday, 4 May 2007

My Research into Palaeozoic Communities

Yesterday I began writing a little bit about what I do, so if you want to catch up check out Part 1. My goal while I’m at Bristol is to compile a community-level study of tetrapod diversity and to compare it to Mike Benton’s global pattern of tetrapod diversity. I hope that my research will aid our understanding of some ‘big’ questions such as:
1) Is global diversity a reasonable measure of true biodiversity?
2) How did tetrapods diversify? Did they conquer new niches or expand into new habitats?
3) How did mass extinction events effect community structure?

But even more interestingly, this study has an application to our present situation. We are witnessing a biodiversity crisis right now and it is not clear whether it is simply a part of Earth’s natural cycle or massive impact by human presence (though to be honest I lean towards the latter). Studying past communities helps us understand more about our present situation.

The first part of my research covered the Palaeozoic, from the origin of tetrapods about 375 million years ago to about 250 million years ago. At this time there were no birds, no mammals and no dinosaurs. The landscape was dominated by large amphibians and the first reptiles. Amphibians at the time were not like frogs but more like very large salamanders, and the largest of these superficially resembled crocodiles (For example, see my post of Parotosuchus). This period of time ended with the largest mass extinction event, in Earth’s history, the Permo-Triassic event 251 million years ago, when over 90% of Earth’s species went extinct.

During the 125 million years though, a lot of changes took place. I realize this post has gotten long already so I will continue more next week starting with a look at the first tetrapods, who possessed a strange oddity that we rarely see today and one that has changed our understanding of the evolution of life on land. Can you spot this oddity in the image to the right?

Click to view a larger image at http://universe-review.ca/I10-72-Acanthostega.jpg

Thursday, 3 May 2007

A little bit about my job…

I’m a palaeontologist at the University of Bristol, currently in the (yikes!) third year of my PhD. But what exactly DO I DO?!?!? Well I don’t fit into the stereotypes of Jurassic Park and Ross from Friends. I don’t spend most of my days in the hot Mongolian desert carefully brushing sand away to reveal amazing and perfectly intact dinosaur skeletons. Sometimes I wish I did though, because to be honest I spend most of my time in the office, counting.

Yes, counting, This is what I do, count animals form different parts of Earths’ past and from all over the world. But to what end? I’m a ‘Macroevolutionist’ so I like to think about the ‘Big picture’, which sounds grand but to be honest can be a bit tedious because big picture stuff often means gathering lots of data, compiling it, and producing graphs. To add a little excitement to my day sometimes I add colour to my graphs and occasionally throw in a pie chart just to be a little crazy.

Seriously though, my supervisor, Mike Benton, has spent a lot of his career counting and has come up with some pretty intriguing insights about biodiversity and Earth’s past. One of his biggest contributions has been the this graph, which is a count of the all of the tetrapods (amphibians, reptiles, mammals and birds) that we have found in the fossil record, from their origin, almost 400 million years ago to the present. As you can see the diversity of tetrapods has risen almost exponentially since their origin to the present day, punctuated occasionally by a mass extinction event, such as the Permo-Triassic event 250 million years ago, when over 90% of Earth’s species went extinct.

But the trouble with this graph is that counting the number of fossils we have from different times is Earth’s history reveals a similar pattern, so it is difficult to say whether Mike’s graph is a true reflection of diversity or simply an artifact of the rock record. This is where my research comes in. I am studying the diversity within communities through time, a study that is independent of these artifacts so I will see if community diversity is similar to global diversity and what the implications are. If you’re still with me and haven’t fallen asleep, tomorrow I will discuss some of early research, including (just for you Will:), Romer’s Gap.

Wednesday, 2 May 2007

Prehistoric Location, Location, Location

Human nature doesn’t change. Tour any archeological site and you will find necessities, desires and comforts of life common to all people. In particular this applies to the place we call home. A house buyer today views properties with a mental checklist of desired features and according to recent researchers, prehistoric cave-dwelling Britons did the same thousands of years ago.

A survey of over 400 caves in Northern England shows that people living in this area from 4,000 to 2,000 B.C. selected their homes based on five important features. Caves were favoured if they

*Were located at a higher altitude
*Had an east or west facing entrances
*Had large entrances
*Included deep passages
*Had a level area just outside of the entrance

Archaeologists discovered that the Peak District, a productive area for agriculture today, attracted more prehistoric cave users than the Yorkshire Dales. But caves were also used for more transitory purposes: sometimes caves were employed like roadside motels, where travellers would stop in for a few nights to rest before continuing their journeys

The benefits of this project include the discovery of many previously unexplored caves throughout Britain, a well-practiced methodology for surveying archeological sites, and an excellent compilation of data that will aid future researchers.

Blogroll Additions

Last week’s call for blogs has resulted in some great additions! Check out:

A California Nature Photographers Journal
Find out where, what, and how to photograph nature in California.

Interrogating Nature
A sensible and critical approach to all sorts of biology related topics.

Secret Sex Lives of Animals
A weekly column on the bizarre, wonderful, colourful and sometimes shocking world of animal mating habits.

The Domestic Minx
A deliciously dysfunctional diary about domestic living.

The Dragon's Tales
A great mix of science and current events from all over the globe.

Tuesday, 1 May 2007

Lonesome George isn’t alone anymore

Lonesome George, the giant Galapagos tortoise that has become a conservation icon may not be the last of his kind after all. George was thought to be the only survivor of a Geochelone abingdoni, a species of tortoise native to the Pinta isle.

But this week, Current Biology has reported a hybrid of the Pinta tortoise and another species discovered on Isabela isle. So the new tortoise, though not completely like George, is proof that hybrids are possible and the future of the George’s species doesn’t look as bleak anymore.

The new turtle is male so can not mate with George, who seems happy as a hermit. George has snubbed the many opportunities he has been given to mate with female tortoises of closely related species.

Researchers hope that a more thorough sampling of the 2,000 tortoises living on the island could reveal another of Georg’s species but are cautious as the project may be expensive and time-consuming.

It is thought that the collapse of the giant tortoise population on Pinta is due in large part to whaling activities in the Pacific during the 18th and 19th Centuries when sailors would take tortoises to store as food on their ships. They pefered the females, which were smaller and easier targets in lowland areas during the egg-laying season. By the middle of the 20th Century, only one giant tortoise was left on Pinta: George who is thought to have been born in the 1920s.