It has always been the goal of humanity to understand the world around them, Aristotle looked to the stars, Einstein looked to atoms, and Freud looked to psychology. Therefore, it should come as no surprise that scientists have consistently delved into the microscopic world to learn more about diseases – specifically, what causes them and what can cure them. DNA sequencing helps in that process of finding cures for disease or treatments. But to do so, you must learn the lingo of DNA coding and understand the fundamentals of that.
The History and Emergence of PCR
Once one delves into the world of DNA, it becomes evident how intricate it really is. As such, PCR (Polymerase Chain Reaction) was developed as a way to better sequence and copy DNA for further study. The entire process became a major game changer at the time it came out in the nineties. It even was recognized for its impact in 1993 with a Nobel Prize in Chemistry.
Today, PCR is used in a variety of practices for DNA: diagnosing disease, identifying bacteria, matching DNA in criminal cases, etc. Because sequencing DNA is a complex process, the same applies to PCR, which is partially why it takes so long to have a PCR test conducted. Fortunately, a new study could present a solution to that problem.
What the New Study Reveals
The study, which was conducted by researchers from the University of California in Berkeley, was published in Light Science & Applications. Of course, speeding up the PCR process has been talked about for years, and yet, no one was able to come up with a feasible way to carry it out.
To finally accomplish the task, researchers used LEDs to heat electrons in the DNA solution are heated on gold film, which acts as a conductor. By doing so, the temperatures increased at fifty-five degrees Fahrenheit per second and cooled down nearly as fast – only ten degrees slower than the heating process. With this new method, the PCR test can be conducted in minutes rather than hours.
Everyday, technology is making it easier to tackle problems in science, medicine, and even at home.
The exact history of how we came to be is one that is still quite unclear and constantly revised. Many cultures around the world hold their own creation stories about the creation of the world and how the people came to be. But we all have one thing in common, the Earth.
This is why the Human Genome Project went underway in 2005 to help map out the genetic trail across the world. What little is known about the map thus far can be found on here on the National Geographic website.
the origins of native americans
But also in a documentary/book that features geneticist and anthropologist Spencer Wells called the Journey of Man: A Genetic Odyssey. As mentioned, the story was made into a documentary as well, detailing the journey of tracing the trail across the world.
The origins of Native Americans came about in the last few minutes of the film. It suggested that the origins of Native Americans point to Siberia, based on blood analysis.
A new study shows evidence for a different story of the origins of Native Americans
Up to then, that’s all we really knew about the genetic trail of humankind and recently a new study was published on the 21st of this month. This study was published in Nature that suggested a different story for certain groups of people in the Americas.
In the study, the origins of Native Americans, more specifically the ones in South America by the Amazon, may share more traits with the indigenous people of Australia, New Guineans, etc. This interesting note was not seen in other natives from the North or Central Americas.
Of course, such a finding was interesting, surprising and threw off everything that was known thus far from the Genome project. So further and more intensive studies were conducted on the area where the link showed up.
interesting ramifications of study
The results showed that the finding was not a fluke, but also suggested the link may be older than the migration into the Americas. But to gauge which group came first, where from, and other such questions, they need to get a DNA sample from the remains of that group of people.
As you can imagine, there have not been any found as of yet. But since there is a link to Australians, looking at remains from there may be an option as well. All this new research tells us is that perhaps it wasn’t just a one-way stop that the Americas came to be populated.
Early Europeans were more closely related to their Neanderthal ancestors say geneticists after analyzing ancient DNA from a 40,000 year old human jawbone. The jawbone found in Romania in 2002 has provided the first genetic evidence of modern humans interbreeding with Neanderthals in Europe.
Homo sapiens and our Neanderthal Ancestors, Homo neanderthalensis
About 45,000 years ago and before then, Europe’s only human population was Homo neanderthalensis. But within only 10,000 years, the Neanderthal population had become extinct, replaced by Homo sapiens, or modern humans who had started to spread across the continent. Before being completely wiped out, our Neanderthal ancestors contributed to our genome. With the exception of sub-Saharan descendants, on average at least one to three percent of the modern human genome comes from Neanderthals.
The transition between species happened rather quickly in evolutionary terms. But what caused the dramatic shift?
Researchers have long known the two species interacted with each other as archaeological evidence has been found. During the time period that modern humans and Neanderthals were neighbors in Europe, there were cultural exchanges between the two groups as seen in subtle changes in tool-making, burial rituals and even in body decoration habits. However, those studies have lacked one important clue in the evolutionary game during that period: skeletons.
The Discovery of the Jawbone, the Link Between Modern Humans and Neanderthals
When archaeologists unearthed a jawbone in a Romanian cave in 2002, they were puzzled as to its origins. Besides a second skull found near the jawbone in Oase Cave, there was no evidence of other artifacts to indicate who the individuals were or to what culture they belonged. The physical features also presented a challenge to the anthropologists. Many of the features were clearly those of modern humans, but some definitively Neanderthal traits were also present. The anthropologists theorized that the two individuals must have been descendants of both groups.
How a Single Jawbone Gave Away Our Neanderthal Ancestors’ Biggest Secret
Pääbo and Reich’s team set about a difficult quest to obtain the jawbone’s ancient DNA. Not only had it been sitting in soil filled with microbes for over 40,000 years, but since being found in 2002, it had over a decade of handling to be contaminated with several sets of modern human DNA.
Qiaomei Fu, then a graduate student, applied modern methods Pääbo’s lab had pioneered to retrieve the DNA via genetic probes. These methods spanned the DNA against 3.7 million human genome positions to evaluate the variations between human populations. Fu was able to separate the ancient DNA from its contaminants by restricting her analysis to DNA with a specific type of damage which resulted from deterioration that had occurred over thousands of years.
The DNA analysis revealed rather than the normal Neanderthal contribution of one to three percent in the genome, an astonishing six to nine percent of the jawbone’s genome came from Neanderthals.
Interbreeding with Our Neanderthal Ancestors
The new study suggests that the jawbone is evidence of modern humans interbreeding with Neanderthals more recently than previously postulated. As DNA passes from each generation, each segment is broken and recombined. With each generation, the DNA of all the other ancestors is interspersed. Reich’s team found segments of intact Neanderthal DNA that was large enough to indicate that the DNA hadn’t been passed down for more than four to six generations.
“In the last few years, we’ve documented interbreeding between Neanderthals and modern humans,” Reich says, “but we never thought we’d be so lucky to find someone so close to that event.”
Amazingly, the study has also proven the Oase cave individuals don’t have any living relatives in Romania or anywhere else for that matter. The team believes instead of passing on his ancestry, the individuals were part of a group that had, like the Neanderthals, disappeared after the modern humans took over.
Looking far back at our ancestors, look how far we’ve come with MUSIO:
