She Has Her Mother's Laugh

She Has Her Mother's Laugh: The Powers, Perversions, and Potential of Heredity

by Carl Zimmer.

This tome is an in-depth look at the history and science of heredity, and genetics, AND genealogy. It is not for the casual DNA enthusiast. 

We have come to believe that our DNA makes us who we are. It determines the color of our eyes and hair and the size of our feet. And it can tell us something about the people we are related to and who we are descended from. That is why millions are spent every year on Ancestry DNA tests.

But...


We carry in our bodies a lot of DNA that doesn't belong to us. Some of it is the DNA of the bacteria and viruses that we are hosts to. Some of these hitchhikers are disease-causing and some are beneficial. Like the bacteria in our stomachs.

But the story of our DNA is much more complex than that.

Did you know that mothers can carry within their bodies cells (and DNA) from the children they have been pregnant with? Scientists have discovered that these cells persist in the woman's body decades after the pregnancy, and can include cells from miscarried and aborted pregnancies.

But stranger still are the cases of mosaics and chimeras. Mosaics+ is where some cells developed differently than most, resulting in "patches" of difference. Chimeras++ are where two embryos get started, like for twins, but they combine together and result in one baby being born. That baby will always carry two sets of DNA.

Also, our DNA can undergo mutations that can be benign or cause catastrophic results.

So when we send in our DNA sample, just which DNA is being tested? And what does all of this mean for the accuracy of DNA tests??

If you want to get a clearer picture of what is going on in the science and theory of DNA in a book not written for scientists, check out  She Has Her Mother's Laugh HERE.

Upcoming GENEALOGY SLAM:

Don't forget to sign up for the Genealogy Slam coming up on November 3rd. We will have 3 learning opportunities, DOOR PRIZES, and REFRESHMENTS! Sign up HERE.

If you want more information on which classes are being offered, check out last week's BLOG.

Remember that this Slam will be held at the Brunswick Library.

Here is some new vocabulary I learned from She Has Her Mother's Laugh:

*In meiosis, when the precursor sperm and egg cells replicate, the DNA splits down the middle and duplicates itself, like in mitosis. In meiosis, after the replication, proteins slice the chromosomes and when the cells repair themselves, some of the DNA  gets exchanged or "reshuffled".
+ Glossary - Mosaics - genetic variation among somatic and germ cells in a single multi-cellular organism
++(Wikipedia - chimaera (chimæra) is a single organism composed of cells with distinct genotypes. In animals, this means an individual derived from two or more zygotes, which can include possessing blood cells of different blood types, subtle variations in form (phenotype) and, if the zygotes were of differing sexes, then even the possession of both female and male sex organs[1] Animal chimeras are produced by the merger of multiple fertilized eggs. Normally, genetic chimerism is not visible on casual inspection; however, it has been detected in the course of proving parentage.[2])