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Scientists piece together the story of humans and dogs
A new study tracks the human-dog relationship through DNA.
- The earliest dog, not wolf, found so far comes from over 15,000 years ago.
- A new study tracks the travel and development of dogs since the end of the Ice Age.
- Insights are derived by comparing ancient canine DNA with ancient human DNA.
We know that at some point long ago there were wild wolves who became companions for humans, and eventually evolved into dogs. The oldest verified dog remains, found in Germany, are from 15,000-16,000 years ago. Much of the story remains mysterious, though. Where it happened, for example: There are reports of dogs in ancient Siberia, in Europe, and the Near East. There are signs of pooches in the Americas some 10,00 years ago. Are all these dogs connected? And how did they become human companions in so many places and cultures?
A new study of ancient human and dog DNA, considered apart and together, published in the journal Science, fills in some of the missing pages in this long-running love story.
"Dogs are our oldest and closest animal partner. Using DNA from ancient dogs is showing us just how far back our shared history goes and will ultimately help us understand when and where this deep relationship began," says one of the study's contributors, Human Evolutionary Biologist Greger Larson of the University of Oxford in the UK.
DNA gets around
Assyrian dog relief
Credit: Wikimedia Commons
The research is the product of a collaboration between Larson and paleogenomicist Pontus Skoglund of the UK's Francis Crick Institute. Skoglund is an expert in canine evolution, working with teams at both institutions as well as the University of Vienna.
The researchers analyzed DNA from over 2,000 sets of canine skeletal remains, some of which dated back as far as 11,000 years. Working with ancient DNA from Siberia, Europe, and the Near East, the researchers were able to add 27 newly sequenced dog genomes to the previously sequenced five.
The researchers compared the canine DNA to the genomes of 17 human individuals who lived during the same time frames in search of common influences that might further establish their connection. Indeed, correspondences were seen that reflected the impacts of humans bringing their dogs along with them as they migrated around the world.
They found that Swedish farmers and their dogs are both descended from canines of the Near East, suggesting that man and dog followed the development of agriculture together through Europe. On the other hand, German farmers 7,000 years ago came from the Near East, but their dogs didn't.
Credit: Sabine Schönfeld/Adobe Stock
Based on their analysis, the scientists assert that by 11,000 years ago, just after the Ice age, there were already five distinct families (or lineages) of dogs, so the German remains were no outlier. These lineages eventually developed into later lines.
Some of this occurred through interbreeding with other dogs and also through mating with their wild wolf cousins. Comparisons between ancient dog and wolf DNA revealed a surprise: Wolves picked up DNA from dogs, but, at least judging by the remains available, there was little or no gene flow back in the other direction. Larson suggests to Science that the evidence may have been tampered with, so to speak — if a dog started behaving like a wolf, its human may well have simply gotten rid of it.
Anders Bergström is the lead author of the study, and he points out a mystery it reveals: "If we look back more than four or five thousand years ago, we can see that Europe was a very diverse place when it came to dogs. Although the European dogs we see today come in such an extraordinary array of shapes and forms, genetically they derive from only a very narrow subset of the diversity that used to exist." Why — and how — one line of dogs so dominated early Europe as to wipe out other lineages remains a mystery. The researchers found no human development that mirrors, or could explain, this event.
A dog's life
It's fun to realize that ancient dog lineages persist to this day. It turns out Chihuahuas have traces of ancient American dogs, and Huskies bear traces of their cold-weather ancestors. Skoglund tells Science that on any given day in a modern dog park, you may be looking at lineages that date back 11,000 years.
It's likely that subsequent research will reveal even more. Says co-author and University of Vienna group leader Ron Pinhasi, "Just as ancient DNA has revolutionized the study of our own ancestors, it's now starting to do the same for dogs and other domesticated animals. Studying our animal companions adds another layer to our understanding of human history."
- Ancient cats drove many dogs to extinction - Big Think ›
- Neolithic dog recreated using an ancient skull - Big Think ›
- DNA Analysis Shows the Evolution of Dog Breeds - Big Think ›
How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.
- A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
- It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
- While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Tribalism and discrimination<p>One question the "Genetic Pressure" series explores: What would tribalism and discrimination look like in a world with designer babies? As designer babies grow up, they could be noticeably different from other people, potentially being smarter, more attractive and healthier. This could breed resentment between the groups—as it does in the series.</p><p>"[Designer babies] slowly find that 'everyone else,' and even their own parents, becomes less and less tolerable," author Eugene Clark told Big Think. "Meanwhile, everyone else slowly feels threatened by the designer babies."</p><p>For example, one character in the series who was born a designer baby faces discrimination and harassment from "normal people"—they call her "soulless" and say she was "made in a factory," a "consumer product." </p><p>Would such divisions emerge in the real world? The answer may depend on who's able to afford designer baby services. If it's only the ultra-wealthy, then it's easy to imagine how being a designer baby could be seen by society as a kind of hyper-privilege, which designer babies would have to reckon with. </p><p>Even if people from all socioeconomic backgrounds can someday afford designer babies, people born designer babies may struggle with tough existential questions: Can they ever take full credit for things they achieve, or were they born with an unfair advantage? To what extent should they spend their lives helping the less fortunate? </p>
Sexuality dilemmas<p>Sexuality presents another set of thorny questions. If a designer baby industry someday allows people to optimize humans for attractiveness, designer babies could grow up to find themselves surrounded by ultra-attractive people. That may not sound like a big problem.</p><p>But consider that, if designer babies someday become the standard way to have children, there'd necessarily be a years-long gap in which only some people are having designer babies. Meanwhile, the rest of society would be having children the old-fashioned way. So, in terms of attractiveness, society could see increasingly apparent disparities in physical appearances between the two groups. "Normal people" could begin to seem increasingly ugly.</p><p>But ultra-attractive people who were born designer babies could face problems, too. One could be the loss of body image. </p><p>When designer babies grow up in the "Genetic Pressure" series, men look like all the other men, and women look like all the other women. This homogeneity of physical appearance occurs because parents of designer babies start following trends, all choosing similar traits for their children: tall, athletic build, olive skin, etc. </p><p>Sure, facial traits remain relatively unique, but everyone's more or less equally attractive. And this causes strange changes to sexual preferences.</p><p>"In a society of sexual equals, they start looking for other differentiators," he said, noting that violet-colored eyes become a rare trait that genetically engineered humans find especially attractive in the series.</p><p>But what about sexual relationships between genetically engineered humans and "normal" people? In the "Genetic Pressure" series, many "normal" people want to have kids with (or at least have sex with) genetically engineered humans. But a minority of engineered humans oppose breeding with "normal" people, and this leads to an ideology that considers engineered humans to be racially supreme. </p>
Regulating designer babies<p>On a policy level, there are many open questions about how governments might legislate a world with designer babies. But it's not totally new territory, considering the West's dark history of eugenics experiments.</p><p>In the 20th century, the U.S. conducted multiple eugenics programs, including immigration restrictions based on genetic inferiority and forced sterilizations. In 1927, for example, the Supreme Court ruled that forcibly sterilizing the mentally handicapped didn't violate the Constitution. Supreme Court Justice Oliver Wendall Holmes wrote, "… three generations of imbeciles are enough." </p><p>After the Holocaust, eugenics programs became increasingly taboo and regulated in the U.S. (though some states continued forced sterilizations <a href="https://www.uvm.edu/~lkaelber/eugenics/" target="_blank">into the 1970s</a>). In recent years, some policymakers and scientists have expressed concerns about how gene-editing technologies could reanimate the eugenics nightmares of the 20th century. </p><p>Currently, the U.S. doesn't explicitly ban human germline genetic editing on the federal level, but a combination of laws effectively render it <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">illegal to implant a genetically modified embryo</a>. Part of the reason is that scientists still aren't sure of the unintended consequences of new gene-editing technologies. </p><p>But there are also concerns that these technologies could usher in a new era of eugenics. After all, the function of a designer baby industry, like the one in the "Genetic Pressure" series, wouldn't necessarily be limited to eliminating genetic diseases; it could also work to increase the occurrence of "desirable" traits. </p><p>If the industry did that, it'd effectively signal that the <em>opposites of those traits are undesirable. </em>As the International Bioethics Committee <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">wrote</a>, this would "jeopardize the inherent and therefore equal dignity of all human beings and renew eugenics, disguised as the fulfillment of the wish for a better, improved life."</p><p><em>"Genetic Pressure Volume I: Baby Steps"</em><em> by Eugene Clark is <a href="http://bigth.ink/38VhJn3" target="_blank">available now.</a></em></p>
Meteorologists propose a stunning new explanation for the mysterious events in the Bermuda Triangle.
One of life's great mysteries, the Bermuda Triangle might have finally found an explanation. This strange region, that lies in the North Atlantic Ocean between Bermuda, Miami and San Juan, Puerto Rico, has been the presumed cause of dozens and dozens of mind-boggling disappearances of ships and planes.
A unique exoplanet without clouds or haze was found by astrophysicists from Harvard and Smithsonian.
- Astronomers from Harvard and Smithsonian find a very rare "hot Jupiter" exoplanet without clouds or haze.
- Such planets were formed differently from others and offer unique research opportunities.
- Only one other such exoplanet was found previously.
Munazza Alam – a graduate student at the Center for Astrophysics | Harvard & Smithsonian.
Credit: Jackie Faherty
Jupiter's Colorful Cloud Bands Studied by Spacecraft<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="8a72dfe5b407b584cf867852c36211dc"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/GzUzCesfVuw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.
- Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
- The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
- The creatures can reach several meters in length and famously ambush their pray.
A three-dimensional model of the feeding behavior of Bobbit worms and the proposed formation of Pennichnus formosae.
Credit: Scientific Reports
Beware the Bobbit Worm!<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="1f9918e77851242c91382369581d3aac"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/_As1pHhyDHY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
The idea behind the law was simple: make it more difficult for online sex traffickers to find victims.