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Damaraland mole-rats, however, are obligate outbreeders , meaning they will only breed with foreign mole-rats (Burland et al. 2002, Burland et al. 2004). Rickard and Bennett (1997) examined C. damarensis colonies, both in the lab and the wild, from which the dominant female was removed, either due to experimental removal or a natural death. They found that the colony remained reproductively quiescent, or stopped reproduction, until an unrelated male was introduced, then a former female worker would become the new breeder (Rickard and Bennett 1997). Their work provides a strong example of the incest avoidance Damaraland mole-rats have.

For a while, it was thought that incest avoidance in Damaraland mole-rats, unlike in naked mole-rats, was sufficient to maintain the reproductive skew. Reproductive suppression was therefore unnecessary. A recent study by Burland et al. (2004) has called these ideas into question, however. They found from samples taken from wild colonies that unrelated non-breeders of the opposite sex coexisted within colonies, providing opportunities for non-breeders to mate. In addition, they found offspring of queens with different fathers than the male breeders. They suggest that either males pass through the colonies or females can briefly leave (Burland et al. 2004). Either way, non-breeders come into contact with unrelated, potential mates, yet they do not mate. Due to this, Burland et al. (2004) believe some reproductive suppression occurs in C. damarensis as well which contributes to the reproductive skew. They do not know yet at what stage suppression is achieved, ovulation, copulation, or implantation (Burland et al. 2004). In order for any outbreeding to occur, however, some mole-rats must be willing to leave their natal nest and disperse.

Dispersal and morphologically separate castes

So far this paper has examined mainly one strategy for workers, the one in which they stay in the natal colony to maximize their indirect fitness, and how that strategy impacts reproductive suppression and incest avoidance. There is however, a second strategy in which the workers leave their natal colony and disperse, either to form a new colony or invade another, in the hopes of becoming a breeder and gaining direct reproduction (O’Riain et al. 1996). Dispersal for the naked mole-rat and the Damaraland mole-rat has high ecological constraints, though, because digging a new burrow for a new colony in the hard ground is difficult. In addition, a small starting colony experiences a greater risk of not finding food when foraging, and the risk of predation is high when leaving the colony. Spinks et al. (2000) performed a within-species comparison in Cryptomys hottentotus hottentotus , or the common mole-rat, between mole-rats in an arid environment and those in a mesic environment ( [link] ). They found that the inclusive fitness for individuals is no longer maximized after reaching a certain colony size and there are greater fitness benefits in dispersing due to increased competition for resources like food. They also found, however, that the higher ecological constraints at the arid sites forced the individuals to remain in the colony longer due to the higher costs of dispersal (Spinks et al. 2000). These findings suggest that group living for H. glaber and C. damarensis was further encouraged by the large environmental constraints on dispersal.

Questions & Answers

Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
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