On the 7th of September, 1936 the last known Thylacine died at Beaumaris Zoo in Hobart (Tasmania). Although most of the scientific community believe that the Thylacine, or as it is sometimes called the Tasmanian Tiger, is extinct there are occasional reports of sightings, either from Tasmania or elsewhere in Australia.

Researchers at the University of Melbourne believe that extinction does not have to mean forever, and they are pursuing a Thylacine de-extinction project to bring back one of the last of Australia’s marsupial apex predators.

The research team led by Professor Andrew Pask of the Thylacine Integrated Genetic Restoration Research (TIGRR) Lab is confident that a newly signed partnership agreement with Dallas-based Colossal Biosciences will bring the resurrection of the Tasmanian Tiger one step closer.

Conserving Australia’s Wildlife Heritage

The new American/Australian partnership will provide access to CRISPR DNA editing technology and allow scientists to pool their resources in their quest to bring back the Thylacine and to prevent many of Australian’s endangered mammals from going the same way.

Commenting on the significance of the new partnership and the access to state-of-the-art gene editing technology, Professor Pask stated:

“We can now take the giant leaps to conserve Australia’s threatened marsupials and take on the grand challenge of de-extincting animals we had lost.”

The Professor added:

“A lot of the challenges with our efforts can be overcome by an army of scientists working on the same problems simultaneously, conducting and collaborating on the many experiments to accelerate discoveries. With this partnership, we will now have the army we need to make this happen.”

Genome Sequenced

Thylacines (family Thylacinidae) are part of the marsupial order Dasyuromorphia. In 2018, researchers led by Professor Pask sequenced the genome of the Thylacine. This was achieved by extracting DNA samples from the pouch of a young Thylacine preserved in a jar of alcohol (specimen number C5757), part of the marsupial collection at Melbourne Museum. The team were able to read the approximately 3 billion nucleotide “letters” of the Thylacine genome and with the help of powerful computers to sequence them.

Armed with this knowledge, the research team could establish the genetic relationship between the extinct Thylacine and living, closely related members of the Dasyuromorphia such as the Tasmanian devil.

It would be theoretically possible to mimic the Thylacine genome and reconstruct it using marsupial stem cells.

A Focus on Protecting Extant Marsupials

Professor Pask explained that TIGGR will concentrate efforts on establishing the reproductive technologies tailored to Australian marsupials, such as IVF and gestation without a surrogate, as Colossal simultaneously deploy their CRISPR gene editing and computational biology capabilities to reproduce Thylacine DNA. This research will also help in the long-term protection of many of Australia’s indigenous marsupials, study of Thylacine DNA will help scientists to better understand the genetic makeup of closely related, extant genera. This research will influence the next generation of Australia’s marsupial conservation efforts.

This partnership with Colossal follows a significant philanthropic donation of $5 million AUD for the TIGGR Lab earlier this year.

Sharing Expertise

Colossal’s experience in CRISPR gene editing will be partnered with TIGGR’s work sequencing the Thylacine genome and identifying marsupials with similar DNA to provide living cells and a template genome that can then be edited to recreate the genetic instructions required to resurrect the extinct marsupial.

Professor Park added:

“The question everyone asks is ‘how long until we see a living Thylacine’ – and I’ve previously believed in ten years’ time we would have an edited cell that we could then consider progressing into making into an animal. With this partnership, I now believe that in ten years’ time we could have our first living baby Thylacine since they were hunted to extinction close to a century ago.”

The TIGRR Lab is believed to be close to producing the first laboratory-created embryos from Australian marsupial sperm and eggs.

Marsupials have a much shorter gestation period when compared to placental mammals. It is conceivable to produce a marsupial without the aid of a surrogate mother. Growing a marsupial, even a Thylacine in a test-tube from conception to the stage at which it would have been born.

Everything Dinosaur acknowledges the assistance of a media release from the University of Melbourne in the compilation of this article.

A study led by scientists at the Milner Centre for Evolution at the University of Bath suggests that a fundamental cornerstone of evolutionary biology could be misrepresenting taxonomic relationships.

It is usual practice for biologists to establish evolutionary trees that set out the relationships between organisms. New research published in the academic journal “Communications Biology”, suggests that most of the evolutionary trees that have been constructed could be inaccurate and that convergent evolution is much more common than previously thought.

These trees are constructed by comparing anatomical characteristics, but this research suggests evolutionary trees based on the analysis of genetic sequences may be more reliable.

Overturning Centuries of Scholarly Work

Since Charles Darwin erected a “tree of life” in the 19th century, biologists have been trying to develop “family trees” of organisms by carefully examining differences in their anatomy and morphology.

With the development of rapid genetic sequencing techniques, scientists are now able to use genetic (molecular) data to compile evolutionary relationships very quickly and cheaply.

This genetic approach has led to substantial revisions in our understanding. Organisms once thought to be closely related have been demonstrated to belong to very different branches of the evolutionary tree.

Comparing the Two Methods of Building Evolutionary Trees

Scientists at the University of Bath compared evolutionary trees based on a traditional analysis of anatomy/morphology with those created using molecular data. The researchers discovered that the animals grouped together by molecular trees lived more closely together geographically than the animals grouped using the morphological trees, which implies that genetic themed evolutionary trees are more accurate.

Commenting on the significance of this study, one of the co-authors, Matthew Wills, Professor of Evolutionary Paleobiology at the Milner Centre for Evolution (University of Bath) explained:

“It turns out that we’ve got lots of our evolutionary trees wrong. For over a hundred years, we’ve been classifying organisms according to how they look and are put together anatomically, but molecular data often tells us a rather different story. Our study proves statistically that if you build an evolutionary tree of animals based on their molecular data, it often fits much better with their geographical distribution.”

Biogeography – A Reliable Guide to Evolutionary Relationships

Where organisms live, their biogeography, is regarded as an important source of evolutionary evidence that was familiar to 19th century scientists such as Darwin, Owen and Huxley. Genetic studies of animals that bear little similarity to each other such as aardvarks, elephants, golden moles, manatees and elephant shrews demonstrate that they originated from the same branch of the mammalian family tree. Molecular studies place these mammals into a single group called the Afrotheria, so-named because these animals seem to have originated from Africa, so the molecular data matches the biogeography.

Convergent Evolution More Prevalent

The study also found that convergent evolution was more prevalent than previously thought. Convergent evolution occurs when a trait or characteristic evolves separately in two genetically unrelated groups of organisms such as the evolution of tail flukes in cetaceans and the entirely unrelated ichthyosaurs.

Professor Wills added:

“We already have lots of famous examples of convergent evolution, such as flight evolving separately in birds, bats and insects, or complex camera eyes evolving separately in squid and humans. But now with molecular data, we can see that convergent evolution happens all the time, things we thought were closely related often turn out to be far apart on the tree of life.”

The ichthyosaur figure shown in the image above is from the Wild Safari Prehistoric World series.

To view this range of prehistoric animal models: Wild Safari Prehistoric World Figures.

The Professor explained that people who make a living as celebrity doubles or lookalikes are not usually related to the person that they are impersonating. Individuals in a family do not always look the same, it is the same for evolutionary trees.

Professor Wills stated:

“It proves that evolution just keeps on re-inventing things, coming up with a similar solution each time the problem is encountered in a different branch of the evolutionary tree. It means that convergent evolution has been fooling us, even the cleverest evolutionary biologists and anatomists for over a hundred years!”

Everything Dinosaur acknowledges the assistance of a media release from the University of Bath in the compilation of this article.

The scientific paper: “Molecular phylogenies map to biogeography better than morphological ones” by Jack W. Oyston, Mark Wilkinson, Marcello Ruta and Matthew A. Wills published in Communications Biology.

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