The Caveman’s Corner

According to G. Reagan and C. Ross in a study published in Folia Primatologica 71 and reported in the latest issue of Current Anthropology, twins of Wied’s black tufted ear marmosets share a significant amount of genetic information while in the womb. They’re chimeras.

To quote the report:

Starting on the nineteenth day of development and ending by the twenty-ninth, the placentas of twins begin to fuse. During this time, the twins exchange stem cells that carry with them their genetic makeup, with the result that individuals possess both cells inherited at conception that contain the original DNA of their parents and other cells that contain the DNA of their fraternal twins. This pattern, known as chimerism, was found in all bodily tissues sampled, including reproductive gametes. In one instance, a female marmoset passed on her twin brother’s DNA to her offspring, making her children her genetic nieces or nephews.

This has implications for the marmoset pattern of child rearing which involves extensive parental investment, especially by the father.

Because of the stem cell exchange between twins, individuals in a marmoset family group may share more than 50% of their genetic information (the typical degree of relatedness between parents and their offspring or between siblings). This creates a situation in which family members may have more invested in their offspring or siblings than predicted for other species—a possibility that will greatly affect the present understanding of how genetics and behavior interact.

Marmosets aren’t just their brother’s keeper. They’re their brother’s father.

This entry was posted on Thursday, May 29th, 2008 at 4:23 pm and is filed under Primatology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.