Buzz
Neanderthals vanished thousands of years ago, yet 1 to 4% of their DNA persists in the genes of modern Eurasian populations. This isn’t an isolated incident—extinct species continue to influence living creatures today. The power of evolution and genetic inheritance means the echoes of creatures like the cave bear, auroch, and other ancient ancestors still roam in the genetic makeup of today’s species. https://humanorigins.si.edu/evidence/genetics/ancient-dna-and-neanderthals#:~:text=Neanderthals%20have%20contributed%201%2D4,human%20migrations%20back%20into%20Africa
10. Wild Cannabis vs. Modern Cannabis
For many years, the true origin of cannabis remained a mystery, with Central Asia being the most likely birthplace. In 2021, a groundbreaking study aimed to uncover the plant’s origins. The challenge was compounded by centuries of human cultivation, which resulted in numerous strains that clouded the path back to the plant’s original ancestor.
The research revealed unexpected results. After sequencing over 100 cannabis genomes, the study concluded that cannabis actually evolved in China, not Central Asia. The most surprising discovery, however, was the existence of a previously unknown cannabis lineage.
The researchers anticipated finding only the two known cannabis varieties—the hemp plant cultivated for its fibers and cannabis grown for its cannabinoids. However, they discovered a new lineage: feral cannabis, which refers to human-bred strains that have reverted to the wild. These feral plants were found to be more closely related to the original wild ancestor than any current cannabis variety. The study also concluded that this ancient cannabis species is likely extinct.
9. Ghost Lineage / Sub-Saharan Populations
In 2017, scientists studied human saliva to investigate a particular protein responsible for the slippery texture of spit. Known as mucin-7, this protein also traps microbes, potentially shielding the body from harmful organisms. But during the research, the scientists stumbled upon an unexpected discovery.
To conduct their analysis, the researchers collected samples from over 2,500 modern human genomes and focused on the gene for mucin-7, labeled MUC7. They uncovered an intriguing finding: a significant number of people from sub-Saharan Africa had a drastically different version of the MUC7 gene. Further analysis indicated that this version came from an unknown, extinct human species, known as a “ghost lineage.”
This mysterious gene is all that remains of the unknown human species, as no fossils have been found. Experts estimate that the ancestors of modern humans came into contact and possibly interbred with this enigmatic group around 200,000 years ago.
8. The Auroch / Texas Longhorn Cattle
In 2013, the University of Texas released a report tracing the origins of the Texas Longhorn cattle. Previous beliefs claimed these animals descended from a purely European lineage. However, the Longhorn’s ancestry proved to be far more diverse and global.
Genetic analysis of 58 cattle breeds revealed that 85% of the Longhorn’s DNA was “taurine,” a type of cattle that descended from aurochs, the now-extinct wild ox. Although the auroch lived in Europe, taurine cattle were domesticated in the Middle East thousands of years ago. The remaining 15% of Longhorn DNA was “indicine,” which can be traced back to auroch descendants domesticated in India before spreading to Africa and the Iberian Peninsula.
The direct ancestors of the Texas Longhorn were brought to America by Christopher Columbus. Over time, they became feral and developed a wild appearance similar to that of the auroch. Some ranchers appreciated the Longhorn’s resilience and adaptability to harsh environments, leading them to be raised as livestock again.
7. Cave Bears / Brown Bears
The giant cave bear disappeared around 25,000 years ago. Recently, researchers extracted DNA from cave bear fossils and compared it with brown bear genomes. Surprisingly, they discovered that modern brown bears carry between 0.9 and 2.4% cave bear DNA.
This finding was unexpected for two main reasons. First, cave bears and brown bears are quite different species. Cave bears were herbivores, while brown bears are carnivores. Second, cave bears were massive—males could weigh as much as 2,204 pounds (1,000 kg), whereas male brown bears typically weigh around 660 pounds (300 kg). The question of how these two species managed to mate, given their size disparity, remains an intriguing mystery.
The explanation for how this hybridization occurred is not so puzzling. Before the cave bear went extinct, it lived alongside brown bears, creating opportunities for interbreeding. Interestingly, Alaskan brown bears have the least amount of cave bear DNA, while European brown bears possess the highest amount.
6. Denisovans / Tibetans
Denisovans were a mysterious, human-like species known only from a handful of bones and their genome. Denisovan DNA can still be found in several modern populations, including Han Chinese, Tibetans, and Melanesians. However, there is something particularly unique about the Denisovan genetic legacy among Tibetans.
The EPAS1 gene, present in everyone, plays a crucial role in adapting to low oxygen levels in the blood by triggering the production of additional hemoglobin. This boosts the blood's ability to carry oxygen. At lower altitudes, this process works fine, but as one ascends to higher elevations where the air is thinner, EPAS1 must work harder—sometimes with fatal consequences.
When EPAS1 increases hemoglobin to deal with oxygen scarcity, it thickens the blood, which raises the risk of hypertension and heart attacks. This danger is particularly present above 13,000 feet (3,962 meters), but most Tibetans can climb beyond this threshold without issues. This is because their EPAS1 gene, inherited from Denisovans, doesn't overcompensate at high altitudes. It only slightly raises hemoglobin, preventing the severe side effects seen in others.
5. The Enigmatic Wolf / Dogs
The origins of dogs remain elusive. It's not just a matter of examining DNA to pinpoint the exact wolf that evolved into a dog. Domestic dogs first appeared around 33,000 years ago and frequently interbred with wolves, muddling the genetic trail of the original species that became dogs.
To unravel the genetic mystery, scientists sequenced the genomes of two dog breeds, the Australian Dingo and the African Basenji, whose territories hadn't crossed with wolves for millennia. The findings suggested their genetic makeup aligns with a wolf species from Asia, the Middle East, or Eastern Europe, the three regions considered the most likely sites for dog domestication.
Surprisingly, research revealed that dogs and modern wolves are sister species, not ancestors and descendants. This means that dogs did not evolve from the same genetic line as present-day wolves. Instead, the findings point to an extinct wolf species, whose only surviving descendants are dogs.
4. The Pinta Giant Tortoise / Hybrid Galápagos Tortoise
The final Pinta giant tortoise, known as 'Lonesome George,' passed away in 2012. During his lifetime, he gained fame as the last of his species. He lived to be more than 100 years old before dying in captivity.
Once, the Pinta giant tortoise was one of up to 15 tortoise species that roamed the Galápagos Islands. In 2020, researchers visited Isabela Island, where they discovered a female tortoise. Genetic testing revealed she was a hybrid with Pinta giant tortoise ancestry. But this was only the beginning—29 more tortoises with partial Floreana giant tortoise heritage were also found, a species that once lived on Floreana Island, another part of the Galápagos.
All of these hybrids were taken to a breeding center. The discovery of Floreana tortoises has sparked hope for reviving the species, at least in part. To preserve the legacy of Lonesome George, scientists are now actively searching for additional Pinta hybrids across the islands.
3. The Quagga / Plains Zebra
In most cases where the genetic material of an extinct animal survives in another species, it happens through either hybridization or evolution. However, this wasn’t the case with the Quagga and the Plains Zebra.
Zebras are well-known for their iconic stripes, but the Quagga had a unique pattern. Its neck was covered in solid stripes, while the rest of its body had faded stripes that eventually blended into brown or white hindquarters. In 1883, the last known Quagga died in captivity, and the species was declared extinct.
Then came an astonishing revelation. Reinhold Rau from the University of Cape Town discovered that the DNA of the Quagga was identical to that of the Plains Zebra. The Quagga wasn’t a separate species as once thought, but rather a subspecies of the still-existing Plains Zebra.
Rau launched The Quagga Project, selectively breeding Plains Zebras with traits resembling those of the Quagga to bring back the species lost in the 1800s. The project is still ongoing and has successfully created a herd of zebras that genetically and visually resemble the original Quaggas.
2. Two Extinct Frogs / African Clawed Frog
The African clawed frog may not win any beauty contests, but it is a genetic marvel. This unassuming amphibian carries the genetic traces of two extinct species. Researchers refer to these ancient ancestors as S and L.
These two ancestors existed millions of years ago, and their history is just as fascinating. To summarize, an older frog species split into two distinct species, S and L. Over millions of years, these two species began interbreeding, and gradually, they merged into one species again—the African clawed frog.
Thanks to this intriguing history, the African clawed frog’s DNA is incredibly unique. It contains two complete sets of chromosomes—one set from S and another from L. This unusual inheritance doubled its entire genome, a rare phenomenon in nature.
1. Red Wolf / Galveston Island Dogs
Red wolves were once widespread across the southeastern United States. However, hunting and the loss of their natural habitats led to their decline. By the time conservation efforts began in the 1970s, it was too late to save the wild population. While a small number of individuals were placed in breeding programs, the red wolf was declared extinct in the wild by 1980.
On Galveston Island, Texas, coyote-like dogs sparked rumors that the wild red wolf had survived. Geneticists had previously received numerous samples of “red wolves,” but most of these turned out to be coyotes. However, a few years ago, when roadkill from the island was sent to a lab, two astonishing discoveries were made.
The first discovery confirmed that the Galveston dogs were genetically closer to captive red wolves than to coyotes, a significant find in itself. But the second revelation was even more surprising: the island dogs still carried a gene from the original, pure red wolves, a gene that had disappeared from the captive population.
