there is something i've noticed with your posts.
almost all, as in >95%, of your references are sourced from here (sciforums) ...
That is because I'm lazy (just repackaged old posts) and initially my (and the world's source) was a newspaper article in Portuguese. All the intitial papers came from the same Brazilian reaserch group (based at a Catholic university - the Pope accepts evolution as fact) more than a decade ago; however, now there are papers in English. The first I found was by Brazilian Carlos H. Salvador of Laboratory of Ecology and Conservation of Populations, Department of Ecology, Federal University of Rio de Janeiro, Box 68020, Rio de Janeiro, 21941-590, Brazil:
ABSTRACT Cavia intermedia is a rare cavy, endemic to the 10-ha Moleques do Sul Island, southern Brazil. We conducted the 1st study of reproductive and growth patterns for this species in its natural environment. Based on 17 months of monthly population monitoring using capture–mark–recapture methods, females were reproductively active throughout the year. Litter size was small (1 or 2 young per litter), with well-developed offspring that weighed approximately 19% of the mass of an adult female. Sexual maturity was reached later than in other species of this genus, at around 59 days of age or 70% of adult body size. There was no evidence that longevity was longer than for congeneric species. Other than longevity, these characteristics are consistent with the island syndrome, which may contribute to the persistence of this species.
If willing to sign up (free) you can read the entire paper. It probably is his Ph.D. study. It may be that you must be Brazilian to visit the tiny island for research. I bet by now these prea have made at least one Ph.D. for each of the original 40 population.
His comments on the small (1 or 2) litter size and delayed sexual maturity made me now realize other things* the struggle not to starve (food supply limited population to ~ 40 animals) selected for. I. e. rather than have 6 or so in the litter; A liter with only slightly more than 1 in the litter on average bigger (19% of their mother's mass!) and stronger at birth gives your genes had a better change of passing into the next generation. I.e. the population size was static for at least 7000 years. In this case it is best to "put all your eggs in one basket" or more accurately "have one or two bigger, stronger, off-springs than 6 who will all starve."
* I had already noted, that the prea's foreward looking eyes (for better depth perception) was a "free" advantage compared to side looking eyes their ancestors had as unlike them, the prea lived where there were no other animals, like a fox, eating them they needed to kept looking out for in ~360 degree range.
I had noted too that the development of much larger, stronger, rabbit-like hind legs was to be expected as they needed to jump over rocks to find blade of grass to eat, etc. (only a bout 10% of their tiny island has any grass and even it is mainly rocks.
I had also noted that being the smallest (the runt of the litter, if it was more than one, as I was assuming) was an advantage as you could survive with less food
And a few other things that were selected for I had discussed, but I did not know these "delayed sexual maturity and small liters" facts, until reading this article, but in hindsight, they obviously increase the chance your genes will live to reproduce / survive the desperate competition for blades of grass with 5 or 6 smaller, equally young, members of your generation..
