I think we're all aware that DNA can be recovered from specimens - thats not at
issue.
The main issue is relative molecular knowledge - and the increasing demands of
quality DNA [tissue/blood] to allow such a sophisticated analysis to get an
Estimate of population size with some level of confidence.
The Complete Genome is available for Humans and maybe ?20 other creatures,
including Zebra Finch. This means
that the context of tiny bits of DNA (e.g. human, and ancient humans) can be
compared to a complete
reference set. Thats not the case for NParrot.
Sophistication - If we want to sex a bird, this can be done with tiny fragments
of DNA (e.g. feather) for say $10; if we want to identify NParrot (from other
species) we (a Museum or lab) can also use a tiny amount of DNA from feather,
but the analysis is more sophisticated, as it needs be compared to reference
knowledge of other parrots (perhaps choosing a small range of species, Budgies
and Ground parrots). Determining population size is a further quantum jump or
two in sophistication.
Unlike extinct Mammoths theres also no juicy deep-frozen [preserved] bits of
flesh to work on (or blood). There is no similarly preserved tissue available
for NParrot as far as I am aware. So, while mammoths have been extinct for
10,000+ years, there is better quality tissue available for molecular analysis
for them, than is available for Night Parrots.
Determining NParrot populations from bits of existing specimens would be
problematic
(recognising their incredible value and fact you don't want major
damage) ie. availability of tiny bits of dried [non-preserved, and therefore
with DNA increasingly degraded] flesh
from "footpads" or from within a feather - most likely from specimens
>100 years old.
Samples size - if you could get some fresh or well preserved NParrot tissue or
blood, you might get an estimate of population number, but probably with very
broad confidence limits (e.g. with one bird - Result = 10,000 individuals, made
up 95% confidence limits = population is within the range 100 to 20,000 birds),
but with additional samples it may get closer to reality, and narrower
confidence limits.
You might need say 3-5 samples to get an ?ok result, but need more to refine
it. Sample size would be critical is getting an estimate close to "reality".
> From:
> To: ;
> Subject: Re: [Birding-Aus] DNA confirms elusive Night Parrot found
> Date: Sun, 11 Aug 2013 11:48:08 +1000
>
> Colin, it's actually very feasible, in fact highly important DNA has been
> extracted from early human fossils that are 100s or thousands of years old,
> that has been used to build a picture of human evolution. DNA extracted from
> frozen mammoth carcases in Siberia have led to some researchers to propose
> reviving mammoth as a species (I truly hope this does not happen, but that's
> not a discussion for here.) The same has been proposed for thylacines using
> DNA extracted from preserved joeys in museums.
>
> In other words recovery of DNA from museum specimens is well-established
> science. It doesn't need to be a complete genome, just enough long fragments
> to distinguish night parrot from its closest relatives (presumably ground
> parrot and western ground parrot.)
>
> Also distinguishing between human and parrot DNA would be a very simple
> exercise - much more so than for ancient humans as described above.
> Basically the scientists can look at a series of bands on a screen and see
> which ones are human and which non-human, almost as easily as they could
> distinguish a human and a bird footprint.
>
> -----Original Message-----
> From: colin trainor
> Sent: Saturday, August 10, 2013 7:15 PM
> To:
> Subject: [Birding-Aus] DNA confirms elusive Night Parrot found
>
> DNA - Most specimens (?all but 3 perhaps) collected before 1900, so not sure
> how useful it would be.
>
> I'm ignorant of molecular approaches, but this detailed type of analysis may
> not be possible on gnarly old specimens (?better on blood and fresh
> tissue? - of which there is none)
>
> >>>>>>>>>>>>
>
> To:
>
>
>
>
>
>
> Subject:
>
> DNA confirms elusive Night Parrot found
>
>
>
>
> From:
>
> Andrew Hobbs <>
>
>
>
>
> Date:
>
> Sat, 10 Aug 2013 14:22:41 +0800
>
>
>
>
>
>
>
>
>
>
> There are apparently 22 known specimens in various museums around the
> world. I would think it quite possible to use DNA analysis on those to
> make some estimates of population sizes etc. and their relationship to
> the recent samples. I would be surprised if that is not already being
> done or at least considered.
> Cheers
>
> Andrew
>
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