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from the their-genes-should-have-worked-out-more dept.
Tasmanian tigers were suffering from poor genetic diversity prior to being hunted to extinction by humans:
Australian scientists sequenced the genome of the native marsupial, also known as the thylacine. It showed the species, alive until 1936, would have struggled to survive even without human contact. The research also provides further insights into the marsupial's unique appearance.
"Even if we hadn't hunted it to extinction, our analysis showed that the thylacine was in very poor [genetic] health," said lead researcher Dr Andrew Pask, from the University of Melbourne. "The population today would be very susceptible to diseases, and would not be very healthy."
He said problems with genetic diversity could be traced back as far as 70,000 years ago, when the population is thought to have suffered due to a climatic event.
The researchers sequenced the genome from a 106-year-old specimen held by Museums Victoria. They said their study, published in the journal Nature Ecology and Evolution, is one of the most complete genetic blueprints of an extinct species.
Genome of the Tasmanian tiger provides insights into the evolution and demography of an extinct marsupial carnivore (open, DOI: 10.1038/s41559-017-0417-y) (DX)
Related: Huge Population and Lack of Genetic Diversity Killed Off the Passenger Pigeon
(Score: 3, Informative) by Arik on Tuesday December 12 2017, @06:03PM (5 children)
The Tasmanian tiger or thylacine (Thylacinus cynocephalus) was the largest carnivorous Australian marsupial to survive into the modern era. Despite last sharing a common ancestor with the eutherian canids ~160 million years ago, their phenotypic resemblance is considered the most striking example of convergent evolution in mammals. The last known thylacine died in captivity in 1936 and many aspects of the evolutionary history of this unique marsupial apex predator remain unknown. Here we have sequenced the genome of a preserved thylacine pouch young specimen to clarify the phylogenetic position of the thylacine within the carnivorous marsupials, reconstruct its historical demography and examine the genetic basis of its convergence with canids. Retroposon insertion patterns placed the thylacine as the basal lineage in Dasyuromorphia and suggest incomplete lineage sorting in early dasyuromorphs. Demographic analysis indicated a long-term decline in genetic diversity starting well before the arrival of humans in Australia. In spite of their extraordinary phenotypic convergence, comparative genomic analyses demonstrated that amino acid homoplasies between the thylacine and canids are largely consistent with neutral evolution. Furthermore, the genes and pathways targeted by positive selection differ markedly between these species. Together, these findings support models of adaptive convergence driven primarily by cis-regulatory evolution.
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If laughter is the best medicine, who are the best doctors?
(Score: 2) by c0lo on Tuesday December 12 2017, @07:13PM (4 children)
I wonder... how did they infer poor genetic diversity by scanning the genome of one specimen.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 4, Funny) by takyon on Tuesday December 12 2017, @07:14PM (1 child)
The paper is entirely open access this time. Be the change you want to see in the world and RTFA lul.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 3, Informative) by c0lo on Tuesday December 12 2017, @07:19PM
I can't. Sleepless night.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by VLM on Tuesday December 12 2017, @08:46PM (1 child)
Awful EE analogy coming in... genetic code is noisier than the typical executable linux elf files we're used to and analysis of the degraded signals and noise in the code indicates if the code went thru weird filters in the past in addition to the usual white noise that accumulates over time. Made possible by the "modem" in genetic code being pretty good by 1970s standards but pretty inferior by 1990s standards so its possible to have raw genetic code containing encoded nonsense. From memory its not a 1:1 map either and you can have multiple chunks of code do the same protein synthesis.
Its a bad indicator for monotheism... if our genetic code system was created instead of evolved, it was definitely not one smart engineer with one unified clear design, but definitely a very large ANSI / ISO standards committee involved.
(Score: 2) by Arik on Wednesday December 13 2017, @04:40AM
First paragraph was good but this one not so much.
We don't fully understand it yet, so it's quite presumptious to declare it inferior.
It's possible that the 'noise' and 'junk' are there for reasons we don't yet fully understand. It's even possible one of them was to allow this sort of retrospective analysis.
If laughter is the best medicine, who are the best doctors?