Smoking Grandparents leads to Asthma in Grandchildren

          

  The dangers of smoking while pregnant have been known for years now. A child may have several health complications if his or her mother is a smoker. However, these ailments may be a result of the grandparents smoking and not the mother at all. New research has shown that people who smoke are more likely to have grandchildren with asthma. This is one example of how behavior before conception can affect gene expression. In other study, it was demonstrated that a man’s weight at the time of conception can affect the child’s likelihood of obesity. Now, not only is it apparent that behavior can affect genes from parent to child, but grandparent to grandchild.

            This information may reveal links between genetics and evolution. How an organism behaves in an environment may alter the genes it passes on to the next generation. This can allow us to further understand the past and aid us for the future. If people understood how much their health can affect their children and grandchildren and so on, they may take better care of themselves now.

http://news.discovery.com/human/genetics/smoking-while-pregnant-affects-grandkids-150929.htm

http://www.ctvnews.ca/health/paternal-obesity-at-time-of-conception-can-lead-to-overweight-kids-study-1.1647750

Asians and Europeans; Lactose-Intolerant 5,000 Years Ago

     Studying ancient DNA has always been a big part of genetics as it gives insight into the past history of humans. What was generally already found is that around 5,000 years ago, Europeans and Asians are generally light-skinned and - surprisingly - lactose intolerant. During the Bronze Age, which ranged from the years of 3,000 - 5,000 years ago, was a time of mass human migrations throughout the region of Europe and Asia. Because of these large migrations, the present-day demographic structure has been developed. 

     Researchers have sequenced genomes from 101 unearthed ancient humans from Europe and Asia. Although DNA sequences have previously been studied using ancient DNA, the new technology that is available makes for clearer data. It has recently been discovered by Morten Allentoft of the University of Copenhagen’s Natural History Museum and his colleagues that light-skinned Europeans were present at a high frequency already in the Bronze Age, thus implying that light-skinnedness was first developed previous to 5,000 years ago. Another conclusion from their data tells that during the Mesolithic hunter-gatherer age, the presence of blue eyes was already established. 

     These data are set to answer the question, could there be a greater distribution of Neanderthal DNA in the genomes of Europeans and Asians? This is still unclear, however the findings suggests that these humans were settled into Europe and Asia before the Bronze Age.

     Something also interesting about the data is that 5,000 years ago, humans had not evolved the enzyme to break down lactose - the sugar found in milk. In an evolutionary perspective, this makes sense because ancient humans and - in fact, mammals in general - do not need to drink milk to survive after infancy, thus the lactose intolerance. When humans began to produce the enzyme to break down that indicated the start of domestication of animals which did not occur much before 5,000 years ago thanks to the data. 

     I personally think that this article is interesting because there are people who today are still lactose intolerant. The article tries to explain this as their ancestors did not drink much milk, thus never needing the enzyme to break down lactose. It is amazing how using the preserved DNA from bones that have been under the earth for so long can lead to vast discoveries like this. This discovery tells a lot about the time line of when humans became what we are today.

Original Article

More about the Bronze Age

Study About Memories Being Passed to Offspring

A study was done with mice where they were trained to fear the smell of cherry blossoms in a Nature Neuroscience Study. This test affected the sperm production in these mice which sent a signal to the brain and altered the DNA. The Emory University School of Medicine looked at what happened to the sperm and it showed that a section of DNA responsible for sensitivity to the scent were made more active in the sperm. Then the offspring of the mice were sensitive to the smell of cherry blossom and avoided the scent even though they never personally encountered it.



This study showed that the experience of a parent even before reproducing does influence genes, the structure of the  brain, and the nervous system in the following generations. This provides evidence of transgenerational epigenetic inheritance and should be something that is looked at more in humans. This study also helps scientists understand more about neuropsychiatric disorders and other health problems.
Transgenerational epigenetic inheritance was something that I used to wonder about a lot and wondered how it affected offspring and the differences in them. Athletic ability used to be one of those that I thought could influence offspring but most of the time I heard that the idea of that was ridiculous. If mice can be scared of a scent for no reason other than their grandparents being scared of it, then it makes me wonder what other experiences previous generations can pass on to offspring.

Article: http://www.bbc.com/news/health-25156510