Extinction. The last of the Tasmanian Tigers.

The sun is setting. The air is chilling. Winter feels to be not far away. It is a time of great loneliness for me. It is a time between light and dark, life and death.

I heave a heavy sigh and a wide yawn, wide enough to almost lock my mouth open. The wide yawn and the somberness of the encroaching dark awake in my minds eye the wide wide yawn of the last Tasmanian Tiger as captured on grainy black and white movie film years ago.

Her yawn was a cry to the universe and to all of us that can see; "Here I am the last of my kind. I am all alone. I am lonely."

And we pay witness to the end of a species. One of many that have fallen before us. And we have seen it.

Between light and dark. A thought, for what it is worth.

I wrote this a long time ago. I was thinking today. Will I ever see another Blue Jay? A Cardinal? A Crow? A Lion? A Tiger?

Will my Grand Children?

180

I am deeply disappointed that many people don't see saving species as important.

there were so few birds this past year <sigh>

I'm certainly not advocating allowing species to become extinct, but any recent extinctions (and many of the past 50-100 years, depending on the remaining specimens) will be available again soon.

Give it 20 years or so...they're already cloning sheep and cats. Dogs are right around the corner. In 20 years, they should be able to repopulate at least half of the species that have become extinct in the last 50 years.

From a specimen preserved in alcohol. It is my understanding that formaldehyde destroys DNA, but alcohol doesn't. This issue was discussed on a recent documentary about the Tigers. They said they would use a Tasmanian Devil as a surrogate. They must be planning to take the pup from the pouch early.

It's not altogether convincing they are extinct. Too many credible sightings.

It would be so nice. I have read of the things you say. Time will tell.

180

Here is a good link.


http://www.amonline.net.au/thylacine/09.htm

Would you clip some of the info?

From http://www.amonline.net.au/thylacine/09.htm


Could the Thylacine be cloned?


Marsupial Wolf
Thylacinus Cynocephalus
Photographer: H. Burrell
(Australian Museum Photographic Image Archives)



The Australian Museum has a small Thylacine pup preserved in alcohol in 1866. Its cells could be used for cloning. By chance this Thylacine was stored in a jar of alcohol rather than formalin, which would have destroyed the DNA.

There are three things that could be done in the foreseeable future with the Thylacine genetic material.

(1) Extract the DNA (presumably in short pieces) and make a genetic library of this by putting the DNA into bacteria. The sequence could be determined by techniques in current use, but it would be very difficult to put the various pieces in the correct order.

(2) Extract the DNA and compare it using microchip technology to the material of a well-characterised animal (e.g. Tasmanian Devil, S. harrisii). This would allow sequencing of the Thylacine DNA by looking at the differences from S. harrisii and would allow ordering of the pieces of Thylacine DNA. The technology is under development for the human genome project but is years away for most other species, because the microchips have to be prepared for each species individually.


Photo: Anthony Farr
Nature focus, Australian Museum



(3) Extract whole chromosomes in whatever remains of the cells of the Museum pup, put them into artificial cell membranes and fuse these in tissue culture to cell lines of another animal (again, probably the Tasmanian Devil). Selective breeding of these cell lines would be potentially able to create a complete set of Thylacine chromosomes in a living cell. This could be cloned into a surrogate mother in much the same way as sheep and other animals are now being cloned.

(1) can be done now, but is most unlikely ever to lead to anything remotely resembling a Thylacine except in conjunction with the other approaches.

(2) and (3) cannot be done yet and to be possible would require a lot more knowledge of technology and an investment in research into other species that would cost a great deal of money, but would have substantial spin-offs for technology developement. We should develope these approaches to be proven on non-valuable specimens before using the Australian Museum pup.

Should we do (1) now?

Any lab proposing the extraction would have to be well experienced in ancient DNA. All resultant genetic constructs should be available to the general scientific community. The Museum would have to be extremely careful in licensing work on the specimen so that it does not become the proprietary right of another institution to determine what happens to the material. Extracting the DNA will spread the risk so that something remains even if the specimen were somehow lost.

We do however, have to be cautious. Reconstruction of a functioning Thylacine genome will require a lot of information on the modifications of the DNA (and there are many - methylation, imprinting, etc) in different cell types. Individually, these cell types may be in very short supply, so the use of a large amount of any one tissue now could well preclude success later. We need a lot more information (again derived for other animals) on the patterns of such modification.

(3) Extract whole chromosomes in whatever remains of the cells of the Museum pup, put them into artificial cell membranes and fuse these in tissue culture to cell lines of another animal (again, probably the Tasmanian Devil). Selective breeding of these cell lines would be potentially able to create a complete set of Thylacine chromosomes in a living cell. This could be cloned into a surrogate mother in much the same way as sheep and other animals are now being cloned.

that is making the effort. They are also working on a mammoth clone, if memory serves.

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Thanks for posting that.

All the offspring cloned from the one preserved specimen would be the same sex as the original, making captive breeding impossible. Even if a second alcohol-preserved specimen is found that is of the opposite sex, using only two sets of genetic variability would create an incredibly poor gene pool to begin with. Without quite a few individual specimens in proper storage, simply cloning them won't be enough to bring them back.

That's better than nothing.

Wouldn't you welcome a cloned woolly mammoth? Or giant rhinoceros?

It's a start. There's no telling what DNA might turn up to fuel a viable breeding population. Perhaps gene splicing could come into play to solve some problems, with introduced genes later removed?

Never constrain the possibilities of the future with the limitations of the present.

But, you do make a good point.

Cloning a cell is the easy part. Getting those cells to develop into a viable fetus and then training it to survive after birth is the hard part.

While we can theoretically accomplish the first step today, steps 2 and 3 require that we use a "host mother" to implant the eggs into. Extinct species of tiger and rhino may be brought back using still existing species of tigers and rhinos, and we may even be able to restore a mammoth using an elephant, but animals like the Tasmanian Devil and Dodo Bird, lacking any surviving close relatives, simply cannot be cloned, raised, and released successfully. They will likely be extinct forever.

related enough to be a surrogate for a tasmanian tiger clone. According to those making the attempt.

The limitations you suggest are based on current levels of understanding, which always sets the bar too low, as history can attest. In fact, there have been recent developments and discussion of cross-species surrogates/hosts. I may be abusing the nomenclature, this is not my bailiwick, but this is true according to information I encountered.

it was such a delight to see the Monarch butterfly in significant numbers in my flower garden. For the past five years, their numbers have dwindled and it is now a rare occasion to see one at all, although I still keep watch.

In the history of this area, there are reports of a significant salmon migration up the streams to spawn in the many lakes here.

I have visited many of the areas where history accounts have recorded significant salmon migration, and even alewives, were plentiful in thier migration and a significant resource for food for the natives.

The old salmon runs have not seen a single salmon in many many years, perhaps fifty years since one was last seen, and the alewives, so prolifant in their numbers, are also absent in these old runs.

You couldn't look up at any time of the day without seeing them.

Do a Google search for "Sixth extinction" and open a few if you dare.

If you've got a point to make, make it.

I've told a couple people that we're in the midst of a great extinction and the reaction varied from, "Chicken Little!" to various forms of scorn and I could tell that some folks whole day was ruined. Myself, I'm amazed that it's news to anyone. It's an elephant in the living room that's not going anywhere.

Hundreds of species go extinct daily. Many that have not even yet been cataloged. Anyone with a sincere interest can find the data supporting this by opening their eyes. Just take a look around, the signs are clear. The scientific data is a matter of record.

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Scientific Amerian

October 30, 2000

The Current Mass Extinction

The phrase mass extinction usually brings to mind events sparked by dramatic environmental change, such as the asteroid impact that led to the demise of the dinosaurs and many other species 65 million years ago. In fact, five such large-scale extinctions have been identified in the fossil record, and according to findings presented on Friday at the annual meeting of the Society of Vertebrate Paleontology in Mexico City, another is under way. This time the cause is nothing so dramatic as a giant asteroid or a radical shift in climate. Rather, it appears, human pressure is to blame.

Like the other mass extinctions, says University of Michigan paleontologist Catherine Badgely, the current crisis is worldwide, affecting a broad range of species. Certain species of vertebrates (animals with backbones) are particularly vulnerable, she reports, especially those with small geographic ranges or narrow subsistence requirements. The numbers are alarming. One quarter of all mammals are endangered or extinct, as are 15 percent of birds. In both groups the larger species are in the most trouble.

The human pressures threatening these creatures include habitat destruction and modification, overhunting, introduction of foreign species, and the increase in carbon dioxide concentrations. Still, extinction of the animals currently designated as endangered is not inevitable, Badgely says. But in order to preserve them, there needs to be a massive change in human actions. --Kate Wong