Donate to Remove ads

Got a credit card? use our Credit Card & Finance Calculators

Thanks to johnstevens77,Bhoddhisatva,scotia,Anonymous,Cornytiv34, for Donating to support the site

Thylacine

Scientific discovery and discussion
XFool
The full Lemon
Posts: 12636
Joined: November 8th, 2016, 7:21 pm
Been thanked: 2608 times

Thylacine

#523220

Postby XFool » August 17th, 2022, 6:48 pm

Scientists Aim to Bring the Tasmanian Tiger Back From Extinction

Mother Jones

This dog-like creature is pretty darn cute.

mc2fool
Lemon Half
Posts: 7812
Joined: November 4th, 2016, 11:24 am
Has thanked: 7 times
Been thanked: 3017 times

Re: Thylacine

#523268

Postby mc2fool » August 17th, 2022, 9:24 pm

"...scientists were so preoccupied with whether or not they could, that they didn't stop to think if they should..."

https://www.youtube.com/watch?v=g3j9muCo4o0

ursaminortaur
Lemon Half
Posts: 6944
Joined: November 4th, 2016, 3:26 pm
Has thanked: 447 times
Been thanked: 1718 times

Re: Thylacine

#523303

Postby ursaminortaur » August 18th, 2022, 12:08 am

mc2fool wrote:"...scientists were so preoccupied with whether or not they could, that they didn't stop to think if they should..."

https://www.youtube.com/watch?v=g3j9muCo4o0


Unlike dinosaurs the thylacine only went extinct relatively recently. The last captive specimen dying in Hobart Zoo in 1936, the last confirmed wild thylacine having being shot in 1930 though there were unconfirmed reports of wild thylacine up until the 1980s when it was officially declared extinct. Hence it is probably even less controversial to resurrect it than the mammoth which is also being worked on.

servodude
Lemon Half
Posts: 8271
Joined: November 8th, 2016, 5:56 am
Has thanked: 4435 times
Been thanked: 3564 times

Re: Thylacine

#523307

Postby servodude » August 18th, 2022, 2:20 am

ursaminortaur wrote:
mc2fool wrote:"...scientists were so preoccupied with whether or not they could, that they didn't stop to think if they should..."

https://www.youtube.com/watch?v=g3j9muCo4o0


Unlike dinosaurs the thylacine only went extinct relatively recently. The last captive specimen dying in Hobart Zoo in 1936, the last confirmed wild thylacine having being shot in 1930 though there were unconfirmed reports of wild thylacine up until the 1980s when it was officially declared extinct. Hence it is probably even less controversial to resurrect it than the mammoth which is also being worked on.


What will mammoths coming back do to the ethical ivory guitar pick trade?!

I wouldn't actually be surprised if the Thylacine pulled a mountain pygmy possum on us and appeared one day
- there is a large part of Tasmania (South West wilderness) where people just don't go

odysseus2000
Lemon Half
Posts: 6364
Joined: November 8th, 2016, 11:33 pm
Has thanked: 1530 times
Been thanked: 959 times

Re: Thylacine

#523566

Postby odysseus2000 » August 18th, 2022, 6:54 pm

I always wonder if one can be sure if a recreated animal will be as the original or something new.

Regards,

servodude
Lemon Half
Posts: 8271
Joined: November 8th, 2016, 5:56 am
Has thanked: 4435 times
Been thanked: 3564 times

Re: Thylacine

#523627

Postby servodude » August 19th, 2022, 1:04 am

odysseus2000 wrote:I always wonder if one can be sure if a recreated animal will be as the original or something new.

Regards,


Depends on how they do it.

taking the DNA and using it to create a new foetus it would be "as the original" - indeed as the original "being"
it is its clone, an identical twin born decades later using a lab (that's the Dolly the Sheep case)

here it seems they are "recreating" the DNA to a degree - if they get that right it should be equivalent

mc2fool
Lemon Half
Posts: 7812
Joined: November 4th, 2016, 11:24 am
Has thanked: 7 times
Been thanked: 3017 times

Re: Thylacine

#523634

Postby mc2fool » August 19th, 2022, 3:20 am

servodude wrote:
odysseus2000 wrote:I always wonder if one can be sure if a recreated animal will be as the original or something new.

Regards,


Depends on how they do it.

taking the DNA and using it to create a new foetus it would be "as the original" - indeed as the original "being"
it is its clone, an identical twin born decades later using a lab (that's the Dolly the Sheep case)

here it seems they are "recreating" the DNA to a degree - if they get that right it should be equivalent

"The scientists aim to reverse this [extinction of the thylacine] by taking stem cells from a living species with similar DNA, the fat-tailed dunnart, and turning them into “thylacine” cells—or the closest approximation possible—using gene editing expertise developed by George Church..."

So they're figuring on starting with this (6–9 cms, 10–20 grams):

Image
https://www.reddit.com/r/Awwducational/ ... at_in_its/

and turning it into this (100-130 cms, 12-22kgs):

Image
https://www.wionews.com/world/extinct-t ... age-411442

That's some approximation!

servodude
Lemon Half
Posts: 8271
Joined: November 8th, 2016, 5:56 am
Has thanked: 4435 times
Been thanked: 3564 times

Re: Thylacine

#523635

Postby servodude » August 19th, 2022, 4:41 am

mc2fool wrote:That's some approximation!


indeed!
But in principle it's just "modifying" code
How close they can get remains to be seen; hard to believe they would try if the gap were too big to work

ursaminortaur
Lemon Half
Posts: 6944
Joined: November 4th, 2016, 3:26 pm
Has thanked: 447 times
Been thanked: 1718 times

Re: Thylacine

#523680

Postby ursaminortaur » August 19th, 2022, 9:55 am

servodude wrote:
odysseus2000 wrote:I always wonder if one can be sure if a recreated animal will be as the original or something new.

Regards,


Depends on how they do it.

taking the DNA and using it to create a new foetus it would be "as the original" - indeed as the original "being"
it is its clone, an identical twin born decades later using a lab (that's the Dolly the Sheep case)

here it seems they are "recreating" the DNA to a degree - if they get that right it should be equivalent


For an extinct species even if they can get the full DNA sequence they will need to insert it into an empty egg cell from a closely related species, and for a mammalian species implant it into a surrogate mother of either the same or yet another closely related species.* This could well effect the methylation pattern of the DNA and therefore effect the expression of the genes. Hence even in that case what is actually produced, although close and having the right DNA, may not be something that could ever have been produced if the original extinct species had not gone extinct. Even with Dolly the sheep where they had real DNA from an adult sheep cell, inserted that into an egg cell from another sheep, and implanted it into a female sheep there were concerns over things like telomere lengths.


* They might need to use a different closely related but slightly more distant species as the surrogate mother if the closely related species providing the egg was too small to carry the pregnancy to term.

mc2fool
Lemon Half
Posts: 7812
Joined: November 4th, 2016, 11:24 am
Has thanked: 7 times
Been thanked: 3017 times

Re: Thylacine

#523694

Postby mc2fool » August 19th, 2022, 11:17 am

servodude wrote:
mc2fool wrote:That's some approximation!

indeed!
But in principle it's just "modifying" code
How close they can get remains to be seen; hard to believe they would try if the gap were too big to work

The OP article was originally in the Guardian, and interestingly they also published another article earlier this year about how decoding numbat DNA could help resurrect the Tasmanian tiger.

https://www.theguardian.com/australia-news/2022/feb/19/de-extinction-puzzle-how-decoding-numbat-dna-could-help-resurrect-the-tasmanian-tiger

Numbat? Wot's that? Well, another related marsupial, and at 35-45cms and 280-700 grams a fair amount closer to the Tassie Tiger than the fat-tailed dunnart ..... but spot the real similarity :D

Image
(ibid)

servodude
Lemon Half
Posts: 8271
Joined: November 8th, 2016, 5:56 am
Has thanked: 4435 times
Been thanked: 3564 times

Re: Thylacine

#523698

Postby servodude » August 19th, 2022, 11:27 am

mc2fool wrote:
servodude wrote:
mc2fool wrote:That's some approximation!

indeed!
But in principle it's just "modifying" code
How close they can get remains to be seen; hard to believe they would try if the gap were too big to work

The OP article was originally in the Guardian, and interestingly they also published another article earlier this year about how decoding numbat DNA could help resurrect the Tasmanian tiger.

https://www.theguardian.com/australia-news/2022/feb/19/de-extinction-puzzle-how-decoding-numbat-dna-could-help-resurrect-the-tasmanian-tiger

Numbat? Wot's that? Well, another related marsupial, and at 35-45cms and 280-700 grams a fair amount closer to the Tassie Tiger than the fat-tailed dunnart ..... but spot the real similarity :D

Image
(ibid)


There's not very many things in the evolutionary cul de sac that is carnivorous marsupials.
So it's disappointing that devils or quolls aren't a useful resource as a donor given they're both relatively abundant in Tassie.

mc2fool
Lemon Half
Posts: 7812
Joined: November 4th, 2016, 11:24 am
Has thanked: 7 times
Been thanked: 3017 times

Re: Thylacine

#523751

Postby mc2fool » August 19th, 2022, 2:55 pm

servodude wrote:There's not very many things in the evolutionary cul de sac that is carnivorous marsupials.
So it's disappointing that devils or quolls aren't a useful resource as a donor given they're both relatively abundant in Tassie.

The dunnart and numbat are actually (mostly) insectivorous (subtle difference, I know). They, the thylacine and the devils/quolls are all in the same order, Dasyuromorphia, but aren't in the same families as each other, so all share the most common recent ancestor at 35-46m years ago. As such I'd assume that all of them contain very overlapping DNA with probably the devils/quolls being more speciated along the way, and so having a bit less of an overlap than dunnarts and numbats. They'd probably still do at a pinch. ;)

Interesting article from Parwinder Kaur, who led the numbat DNA project.

https://theconversation.com/weve-decoded-the-numbat-genome-and-it-could-bring-the-thylacines-resurrection-a-step-closer-176528

And another getting the opinion of five experts, including Parwinder Kaur and two quoted in the original Guardian article, on if we should de-extinct the thylacine.

https://theconversation.com/should-we-bring-back-the-thylacine-we-asked-5-experts-188894

My first reaction on reading of the project to de-extinct the thylacine was, and then? As Corey Bradshaw in the last link (and quoted in the Guardian) says, "Viable populations require thousands of genetically diverse individuals to be able to persist in the wild". And then there's the matter of an ecologically suitable habitat. The experts seem to be divided on whether that still exists or not (see both Guardian articles and both links above).

I am reminded of a conversation with a ranger in the Kanha tiger reserve national park in India. Asked about conserving and increasing the numbers of tigers he talked at length about maintaining prey populations, in particular deer (tigers' favourite food apparently), and at even more length about maintaining the habitat for them, in particular the kinds of grasses etc the deer liked to eat, the latter being apparently what they spent most of their efforts on.

9873210
Lemon Slice
Posts: 986
Joined: December 9th, 2016, 6:44 am
Has thanked: 226 times
Been thanked: 296 times

Re: Thylacine

#523792

Postby 9873210 » August 19th, 2022, 4:17 pm

ursaminortaur wrote:
servodude wrote:
odysseus2000 wrote:I always wonder if one can be sure if a recreated animal will be as the original or something new.

Regards,


here it seems they are "recreating" the DNA to a degree - if they get that right it should be equivalent


For an extinct species even if they can get the full DNA sequence they will need to insert it into an empty egg cell from a closely related species, and for a mammalian species implant it into a surrogate mother of either the same or yet another closely related species.* This could well effect the methylation pattern of the DNA and therefore effect the expression of the genes.

* They might need to use a different closely related but slightly more distant species as the surrogate mother if the closely related species providing the egg was too small to carry the pregnancy to term.


Extending on ursaminotaur's remarks.

The development of an organism is not determined simply by the DNA sequence but is also by the environment at many levels. There is an interplay of genotype and phenotype and both matter.

A chromosome is not just a sequence of DNA. It contains histones and features such as methylation (mentioned by ursaminataur). These control the physical shape of the chromosome and to a large extent which and when genes are expressed. This has major effects on development. So you have to get this right.

At level of the egg cell we have the mechanism that decodes both the DNA sequence and chromosome structure to build proteins. Much of this is highly conserved so eggs from close relatives should work, but there may be subtle differences and they may matter. There are a few odd ball organisms that have at least one non-standard codon to protein mapping. There may be some variations in preferred codons across species.

Also the recreated thylacine eggs will not have thylacine mitochondria. Probably won't matter, but it may.

At a larger scale for animals that care for their young, (e.g. mammals, including marsupials) the mother controls the development environment for the egg. This includes not only temperature, food, oxygen etc. but some more subtle things like the immune system. These may develop differently in a different "gestational" mother. This continues after birth where the correct composition of milk is important. Not only for nutrients but for things like antibodies and hormones.

This may be one reason amphibians generally have larger genomes than mammals. Amphibian eggs need instructions to cope with a range of environments, while a mammal egg will experience far fewer variations, since the environment is controlled by the mother.

At an even larger scale mammals learn, so the social environment matters. An example is house cats. Depending on how they spend their early kittenhood they can become social like lions or solitary like tigers. You could get a clone that looks like a thylacine but does not act like a thylacine.

All of the above is speculative. There is a lot we do not understand about development.

ReformedCharacter
Lemon Quarter
Posts: 3120
Joined: November 4th, 2016, 11:12 am
Has thanked: 3591 times
Been thanked: 1509 times

Re: Thylacine

#523795

Postby ReformedCharacter » August 19th, 2022, 4:29 pm

mc2fool wrote:
My first reaction on reading of the project to de-extinct the thylacine was, and then? As Corey Bradshaw in the last link (and quoted in the Guardian) says, "Viable populations require thousands of genetically diverse individuals to be able to persist in the wild". And then there's the matter of an ecologically suitable habitat. The experts seem to be divided on whether that still exists or not (see both Guardian articles and both links above).

Quite, it's a very interesting experiment but apart from that what is the objective?

RC

XFool
The full Lemon
Posts: 12636
Joined: November 8th, 2016, 7:21 pm
Been thanked: 2608 times

Re: Thylacine

#552440

Postby XFool » December 5th, 2022, 3:06 pm

Tasmanian tiger: Remains of last thylacine found in cupboard after 85 years

BBC News

The remains of the last known Tasmanian tiger - thought lost for 85 years - have been found stashed in the cupboard of an Australian museum.

pje16
Lemon Half
Posts: 6050
Joined: May 30th, 2021, 6:01 pm
Has thanked: 1843 times
Been thanked: 2066 times

Re: Thylacine

#552443

Postby pje16 » December 5th, 2022, 3:10 pm

ReformedCharacter wrote:Quite, it's a very interesting experiment but apart from that what is the objective?
RC

Scientists sometimes think they are God :roll:


Return to “Science”

Who is online

Users browsing this forum: No registered users and 4 guests