Giraffes are ‘choosy’ when hanging out with friends

Studying social relationships among female giraffes may provide essential information for the management and conservation of the species, a study by The University of Queensland (UQ) has found. Lead researcher, Ms Kerryn Carter, from UQ's School of Biological Sciences observed the social groupings of 535 individually identified wild giraffes in Etosha National Park in Namibia for 14 months. The study discovered that giraffes have more complex relationships and social networks than previously thought, and this is of importance to understanding the evolution of animal and human sociality. “Giraffes show a fission-fusion social system, like humans, where individuals temporarily associate so that the numbers and identities of individuals in groups changes frequently," Ms Carter said. “Until recently, giraffes were thought to show no apparent pattern to their relationships.” Ms Carter looked at the frequency at which each giraffe pair associated, while taking into account how much their home ranges overlapped, and thus their ability to meet on a regular basis. Her results have been published in the scientific journal Animal Behaviour. “We found, rather than females interacting non-selectively as previously thought, individual female giraffes preferred to be in groups with particular females and avoided others,” Ms Carter said. “Surprisingly, home range overlap and kinship together did not explain much about these female-female relationships.” Females' individual social preferences, their ages and their reproductive states may contribute to their choices of female associates. Research is continuing on to understand which factors contribute to these preferences. Understanding the patterns of social networks in species such as giraffes helps us understand how diseases may spread through a population and how individuals may learn about their...

Monkeys Born From Stem Cells

The birth of three monkeys from a stem cellresearch program is being hailed as a major breakthrough in genetic engineering. It appears that the mouse stem cells widely used in studies, follow a different developmental process, that was previously thought to be identical to primate and human. Scientists have opened a window to a new strategy, and one which has seemed out of reach for more than ten years. Now it is possible for cloning primate and even human stem cells, into living breathing organisms. The monkeys were all male and appear to be healthy. The work, by developmental biologist Masahito Tachibana of the Oregon National Primate Research Center, was reported in the journal 'Cell'. Instead of using embryonic stem cells cultured from lines of cells grown in petri dishes, the researchers used early-stage stem cells taken directly from monkey four-cell embryos to create 10 chimeric, or genetically mixed, embryos. The cells were combined from the early stage embryos, so the DNA was mixed, and the fetuses were incubated in female monkeys. Three out of the four survived full term and are currently between four and six months old. They carry mixed DNA from six different genetic lineages. Genetically, it's as if they had as many as six parents, an impossibility naturally. More interestingly, although they have both male and female DNA, they are all developing as males, because masculine genes have dominated the monkeys development. The three rhesus monkeys, named Chimero, Roku and Hex, are said to be normal and healthy. The researchers were able to make monkey chimeras only when they mixed cells from very early stage embryos,...
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