Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
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Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#2What I don't fully understand is, usually when scientists try to preserve rare species, there is a critical mass under which there isn't enough genetic diversity to preserve the species (I've seen ~30 quoted for some rare mammals). But in this case, just two individuals were able to start a viable population. Why are these insects different? I can only think of a couple reasons...
- since these insects have a r-selection curve, it's ok if 90% of the offspring are genetic defects, you can always produce another 1,000 eggs
- the insects had maintained such a small population for so long that any critical defects had been bred out
But I'd be interested to hear from a real biologist.
Edit: oops, meant r-selection, not k-selection
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#3This has been here already a couple times... But it's amazing nonetheless.
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#4What I don't fully understand is, usually when scientists try to preserve rare species, there is a critical mass under which there isn't enough genetic diversity to preserve the species (I've seen ~30 quoted for some rare mammals). But in this case, just two individuals were able to start a viable population. Why are these insects different? I can only think of a couple reasons... - since these insects have a r-selec…
The article touches on this a little bit, I think.
Eve's eggs were harvested, incubated (though it turns out only the first 30 were fertile) and became the foundation of the zoo's new population of walking sticks.
I am not a real biologist, but I suspect it is some combination of the factors you suggest and that their genome may be simple enough that most defects make the eggs nonviable.
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#5Alberta is rat free, and is kept that way. Its been rat free for over 50 years now. The border is patrolled to keep the rats out, and there is a hefty $5000 fine for keeping rats.
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#6Its always great to hear a positive story in conservation
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#7Alberta is rat free, and is kept that way. Its been rat free for over 50 years now. The border is patrolled to keep the rats out, and there is a hefty $5000 fine for keeping rats.
Questionable. Rat populations have been found at the Medicine Hat landfill, first in 2012 and again in 2014[1]. I guess it's a good sign that it makes national news when a population is found, but they're almost certainly present elsewhere.
[1] http://www.cbc.ca/news/canada/calgary/several-rats-spotted-a...
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#8Alberta is rat free, and is kept that way. Its been rat free for over 50 years now. The border is patrolled to keep the rats out, and there is a hefty $5000 fine for keeping rats.
Questionable. Rat populations have been found at the Medicine Hat landfill, first in 2012 and again in 2014[1]. I guess it's a good sign that it makes national news when a population is found, but they're almost certainly present elsewhere. [1] http://www.cbc.ca/news/canada/calgary/several-rats-spotted-a...
Yeah, those were big news then. I remember hearing about it. The goal is still definitely to be rat free, and they work hard to tray and keep it that way.
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#9What I don't fully understand is, usually when scientists try to preserve rare species, there is a critical mass under which there isn't enough genetic diversity to preserve the species (I've seen ~30 quoted for some rare mammals). But in this case, just two individuals were able to start a viable population. Why are these insects different? I can only think of a couple reasons... - since these insects have a r-selec…
I'm not a biologist, but that probably hits the nail on the head, though judging by your comment I think you meant k-selection, and it's actually r-selection that pertains to the "spray and pray" approach to offspring. [1]
There's also likely some luck involved that the initial two on that island happened to be viable colony starters.
[1] http://www.bio.miami.edu/tom/courses/bil160/bil160goods/16_r...
Re: Six-Legged Giant Finds Secret Hideaway, Hides for 80 Years (2012)
#10What I don't fully understand is, usually when scientists try to preserve rare species, there is a critical mass under which there isn't enough genetic diversity to preserve the species (I've seen ~30 quoted for some rare mammals). But in this case, just two individuals were able to start a viable population. Why are these insects different? I can only think of a couple reasons... - since these insects have a r-selec…
From the subtley linked 'Husbandry Manual': http://www.aszk.org.au/docs/lhisi.pdf
Section 3.2 (p8)
The population at Melbourne Zoo, being descended from a single pair, appeared to experience increasing symptoms of inbreeding over two generations until four adult males were introduced, descended from a second pair held at Insektus in Sydney, and their genes began to have an influence.
After new males were introduced, no further abnormalities were observed...