Deep in Human DNA, a Gift from the Neanderthals

Unbeknownst to most, the innate defense built in the human body may have come from the early ancestors of the Neanderthals. People of Asian or European descent have some Neanderthals DNA due the the amount of breeding between the modern humans and the Neanderthals long ago. The reason those genes have stuck around through time is due to the possibility of being the reason humans are protected against infections.

As modern humans expanded from Europe and Asia, they "encountered new viruses", possibly from the Neanderthals but also were protected from these same viruses due the the defenses the Neanderthals gave them.

The immune system of a human is quite complex, and in order to learn more about such a "glimpse at the distant medical history of our species", an evolutionary biologist, David Enard, first had to change his approach to the task: starting with finding all the proteins human have that "interact with at least one virus." This reason for this approach being that viruses cannot duplicate singularly: they need a host protein to inject their DNA into and it replicate with the virus DNA.

Dr. Enard discovered that the proteins humans have, "many have changed over the course of evolution" and because of this, he began to wonder how then Neanderthal genes are still somewhat around in the modern human genome. Those particular genes must provide some evolutionary advantage, for which they have been selected for over time. Researchers believe that the beneficial Neanderthal genes were "borrowed" by the modern human to fight infections, and more specifically code for "proteins that interact with viruses." By analyzing the genomes of living humans today, it is clear that many proteins made by these genes mostly interact with only influenza, others only H.I.V. Although those diseases did not directly come from the Neanderthals today, the defense their genes gave humans years ago is still somewhat relevant in humans today.
I am not sure to the extent of which I believe the content in this article. Sure, the innate defense system of the immune system had to come from somewhere, but this seems a little far-fetched. It does makes sense though that if in fact the immune system was due to the modern human interbreeding with Neanderthals, those genes inherited for defense have evolved over time and changed, with the amount of their DNA declining over time.
https://www.nytimes.com/2018/10/04/science/neanderthal-genes-viruses.html
http://humanorigins.si.edu/evidence/human-fossils/species/homo-neanderthalensis
https://www.huffingtonpost.com/quora/what-do-evolutionary-biol_b_3644482.html

Evidence For Possible Unknown Human Relative Found in Modern Human DNA

     We all know that the Neanderthals and Denisovans are the closest relatives to the Homo sapiens (Modern Human) species. However, genetic evidence in Melanesians (Aboriginal Australians, and natives in New Guinea and neighboring islands) hint that there is a possible third extinct hominid relative.



     While many Neanderthal fossils were found in Europe and Asia, and the Denisovans were discovered from DNA from a finger bone and teeth found in a cave in Siberia, the third possible extinct hominid DNA may been preserved in human DNA, and not in fossil evidence, as reported by statistical geneticist Robert Bohlender on October 20 at the annual American Society of Human Genetics meeting. In 2012, a research team suggested that there were also people in Africa carrying DNA from an extinct hominid ancestor. Less than a decade ago, it was even discovered that early humans mixed with other hominid species. Bohlender and his research team concluded that a third hominid group may have bred with the human ancestors of the Melanesians.

   Eske Willerslev and his research team also came to a similar conclusion. They conducted an experiment in which they collected saliva samples from volunteers for DNA sequencing. The DNA examined was from 83 Aboriginal Australians and 25 natives from Papua New Guinea highlands. The researchers found Denisovan-like DNA, but was found to be different and possibly from another hominid species. Willerslev speculates that this DNA can be from Homo erectus or from the extinct Hobbits hominid species, but he is not a hundred percent sure.

  According to evolutionary geneticist Mattias Jakobsson, researchers don't know much about the Denisovan's genetic diversity. He believes that it was possible that a different branch of Denisovans could have been the group that mated with the Melanesians' ancestors. There geneticists like Elizabeth Blue, that believe that the genetic evidence found from Neanderthals and Denisovans is limited. Denisovans may have been spread around the world and have had genetic diversity. If they weren't however, then the genetic evidence could have come from another extinct species.

     I think that it's fascinating how evolutionary evidence could be found in modern human DNA, and not just in fossils. I hope that after further research, scientists would be able to confirm if this genetic evidence came from another distinct hominid species or just another branch of Denisovans. I also think that this evidence can help us learn more about human evolutionary history, along with that of other hominids.

Links:
https://www.sciencenews.org/article/dna-data-offer-evidence-unknown-extinct-human-relative

http://www.nature.com/nature/journal/v538/n7624/full/nature18299.html?cookies=accepted

https://ep70.eventpilot.us/web/page.php?page=IntHtml&project=ASHG16&id=160122719

Our Ancestors' Food Choices continue to Impact our Health

What can happen if you change your vegetarian diet to something else?

For example: Cultures from many parts of the world including India, Africa, and Asia have come from a strict vegetarian diet. And if they were to change this diet to something such as a red meat diet it can have some serious health risk such as developing heart disease, colon cancer, or another disease concerning with the overall health according to researchers.

Can your ancestor's diet alter the microbes within your body?

Researcher have already identified a genetic mutation called rs66698963 and it is found within the FADS2 gene which they came to realize after testing several citizens from Pune, India. This gene is directly linked with people who have ancestors' who have been on the vegetarian and vegan diet. Scientist tried to search for this same gene within a region that predominantly ate red meat exclusively in Kansas, USA. And they found that the gene was seen only in the people who came from a background of ancestors who believed in the vegetarian and vegan diet.

Can this gene be deleted if your ancestor didn't believe in the vegetarian or vegan diet?

In fact, researchers have looked into other regions that have come from a background of mostly a meat based diet such as in the parts of northern Canada and parts of Greenland and Alaska who show no sign of the mutation. This is because for thousands of years the people of this region have come from a background who didn't believe in the vegetarian or vegan diets.

**I believe this article in some parts is true and in other parts is untrue. This is because if it were true there wouldn't be groups of people from various parts of the world converting their diet with rich in red meat to a vegetarian or vegan diet, which is well off rich in fruits and vegetables. Overall, more research can certainly confirm if it is based on genetics or your environment.

Some Cultures Hardwired for Vegetarian Diet

         An article from Discovery News talks about how some people have adapted to vegetarian diets better than others. I personally love to eat meat and found this article interesting to read. Based on what their ancestors ate, people have more of a tolerance for meat in certain areas compared to others. My family is from the Mediterranean and Europe. I do not have a lot of family from northern Europe where their culture has adjusted to the vegetarian diet and evolved the genetic mutation known as rs66698963. Honestly, I’m happy I am not from areas where the mutation have evolved because I cannot imagine not being able to eat a nice steak or a burger in the summer. 

         I think it is so fascinating that genes can vary so much depending where you are from. Genes from people from other states in America alone vary so much alone that thinking at a larger scale and comparing individuals from other countries baffles my mind. The mutation has such an affect that if individuals with the mutation stray from their vegetarian diets, they could have a higher risk than others for heart disease, colon cancer, and a variety of additional health problems associated with inflammation. But also think about this: if what your ancestors at affects your genes and your lifestyle now, how can your lifestyle affect the generations after you?

Here is another article about cultural differences in vegetarianism. 

Some Cultures Hardwired for Vegetarian Diet

       Ever heard of the expression "you are what you eat," well in this study, scientists compared the genetic make up of individuals who have a lineage of vegetarianism to those who eat red meat daily. Scientists discovered the gene that is affected by vegetarianism is called s66698963 found in the FADS2 gene.

The scientists compared genomes to those from Kansans who love red meat, to those from Pune India who have a long history of vegetarians. When searching for the genetic mutation throughout other cultures and populations, researchers found the mutation has spread from South America, Northern Europe, and other similar locations.

Although researchers found the spreading of the mutation, they also discovered the deletion of the mutation in Northern Canada, Greenland, and Alaska this mutation became maladaptive. Results explain there is no Paleo diet out there for anyone. Instead, you can now thank your ancestors for your eating habits and diet patterns.

I found this article extremely interesting due to the fact that I was raised into a meat eating family but since my heritage's primary diet consists of seafood and shellfish my diet for the last 10 years have consisted of a strict pescatarian diet. I never imagined that the diets of my ancestors would have such a strong influence on my diet today.

Click here for original source: http://news.discovery.com/human/genetics/some-cultures-are-hardwired-for-vegetarian-diet-160329.htm

Bringing Back a Galápagos Tortoise Species

Scientists have recently taken on the challenge to bring a Galápagos tortoise species back to life. After George, a Galápagos tortoise over one-hundred years old died in 2012, his species of Pinta tortoise became extinct. There are 8 Galápagos tortoise species scientists believe and George's species can perhaps be brought back to life soon.

George, the last known of his Galápagos tortoise species

In 2008, more than 1,600 tortoises were tagged with their blood samples also being collected that lived on the flanks of the Wolf Volcano on Isabela Island.  These tortoises and their families were originally dumped over a hundred years ago. Eighty-nine percent of the tortoises that were tagged were part Floreana whose full DNA genetic profile were obtained from samples in a museum. What made scientists think the Floreana species might not be fully extinct was that some of these tortoises had genes that indicated that their parents were in fact purebred Floreana. Also, seven of the tortoises had high levels of Pinta DNA, which could mean they could be close living relatives of George.

These scientists finally went back to the volcano to find these tortoises in order to separate them based on their DNA, whether they had high levels of Pinta or high levels of Floreana. The tortoises that were the most genetically close to the original species were then bred. The scientists think that it is possible to breed tortoises that will have 95% of their "lost" ancestral genes, and can hopefully bring back George's Galápagos tortoise species. The next step in this study is to analyze each animal's DNA to begin separating the two species and find those with the least mixed ancestry, which can take 5 to 10 years from now.

This article is one example on how an animal's genetics can be used for conservation of a species of an animal. Hopefully with more information and technology in the future it should be much easier to conserve a species so they cannot go extinct. Also, like in this study, some species can even be brought back to life with genetics so hopefully in the future less animals and even plants will become fully extinct.

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