The dodo is an iconic reminder of man-made extinction!
The Raphus cucullatus is an extinct bird that once lived on an island off the coast of Madagascar in Mauritius. The dodo is a distant relative of pigeons and other pigeons and is often referred to as an example of human extinction.
Dodo dodos doves do not fly, reproduce slowly and are limited to one island, so they are vulnerable to the arrival of humans and rats, as well as the introduction of domesticated animals in the late 1500s. About a century later, only a few paintings and written descriptions of the dodo remain, as well as a small number of bones
What does a dodo look like?
The dodo is a burly gray-brown bird with small wings, strong legs and a large beak. According to a 2004 study in the Journal of Biologists, it was 27 inches (70 centimeters) tall and weighed 28 to 45 pounds (13 to 20 kilograms). Males are slightly larger than females, and dodos are shorter but heavier than modern wild turkeys and swans.
The dodo was extinct long before photography was able to capture a portrait of the dodo, and no bird specimens survived. Julian Pender Hume, a research assistant at the Natural History Museum (NHM) in London, told Vice that the so-called specimen stripping dodo on display at NHM was glued to a plaster cast by a man who had never seen a transitional dodo.
To prove what the dodo actually looked like, modern researchers had to resort to historical paintings and other artworks, as well as early descriptions of Arab and European tourists to Mauritius, whose records were not always accurate.
In particular, a European artist, the 17th-century Flemish painter Roelant Savery, was heavily responsible for the circular image of the dodo that had proliferated in other works of art and cartoons.
Hume said Safri's multi-headed dodos have led many to think that the birds are slow, stupid and clumsy, but evidence from dodo bones suggests that the birds are agile animals that can outperform humans on rocky terrain. According to NHM, the dodo has a large brain and developed olfactory glands, suggesting that, contrary to its popular reputation, it is relatively intelligent and may have a keen sense of smell.
Where dodos live?
The dodo lives on the subtropical volcanic island of Mauritius, now an independent country made up of several islands in the Indian Ocean. Mauritius is located on the southeast coast of Africa, about 700 miles (1,100 km) from Madagascar.
According to the Department of Anthropology at Stanford University, Mauritius and its neighboring islands had no permanent population until the Dutch East India Company established settlements there in the 1600s. By then, the island's former visitors had introduced so many predators that dodos no longer roamed the beaches and mountains. Later, researchers reported in the journal Antelope in 2009 that deforestation had wiped out most of the dodo's woodland habitat.
Why did the dodo go extinct?
According to National Geographic, the dodo was extinct due to a lethal combination of slow evolution and rapid environmental change. Highly specialized environments, fly-averse and slow-breeding species are vulnerable to predators suddenly introduced into their once-safe island homeland.
For millions of years before human explorers set foot on Mauritius, the island was free of large land predators. According to National Geographic, Mauritius' wildlife continues to evolve to fill a variety of niches, but these isolated species are slow to respond to new threats from across the ocean. So the birds were easily caught and killed by hungry Dutch sailors.
It's not just humans who eat dodo. Conversely, according to a 2016 study in the Journal of Vertebrate Paleontology, many exotic species, including mice, pigs, goats and monkeys, may capture and eat dodos and their eggs. Sadly for the dodo, each egg that is swallowed represents the female's only reproductive opportunity that year.
But for newcomers to the island, nutritious, simple meals are within reach of the forest floor. Hume wrote in the 2006 journal Historical Biology that if any precious eggs survive and hatch, introduced animals may outperform juvenile and adult dodos in terms of limited food supplies.
Today, the dodo is officially listed as an extinct species by the International Union for Conservation of Nature.
When did the dodo become extinct?
The official extinction date of the dodo is uncertain. According to a 2004 study published in the journal Nature, unlike the thylacinus cynocephalus, the last known individual of the species died in captivity in 1936, and the dodo population gradually decreased without human observation, circa 1662.
However, some researchers have pointed to reports of dodos in Mauritius in the late 1680s, which Live Science reported in 2013. In the Nature study, the researchers used a statistical method to estimate the extinction of the dodo, pushing the date back to as late as 1690.
Can we bring the dodo back?
Beth Shapiro, a professor of ecology and evolutionary biology at the University of California, Santa Cruz and an evolutionary molecular biologist, said it's unlikely we'll see dodos walking on Earth again anytime soon.
Shapiro told Live Science that there are many reasons why dodos are difficult to revive: they are not good candidates for cloning, because there are few sources of dodo DNA; Bird breeding is really complicated; And there isn't necessarily a habitat for them to go back.
"When most people think about going extinct, they're all imagining clones," Shapiro said. Cloning technology created Dolly the Sheep in 1996 and The Black-footed Ferret Elizabeth Ann in 2020, creating identical copies of individual genes by transplanting DNA from living adult cells into egg cells that have had their nuclei removed. Adult cells contain all the DNA needed to develop into living animals. The egg cells then use that DNA as a blueprint to differentiate themselves into the many kinds of cells the animal needs—skin, organs, blood, and bones.
But the living cells of dodo dodo do not exist, and they have existed for hundreds of years. Instead, Shapiro says, you have to start with closely related animal genomes and then adjust it to resemble a dodo genome.
For example, mammoths are also extinct, and scientists have yet to find any living mammoth cells. But mammoths are closely related to modern Asian elephants (Elephas maximus), so researchers such as George Church, a professor of genetics at Harvard Medical School in Boston, are trying to recover mammoths from extinction by hybridizing with some mammoths. Genes replace part of the elephant genome in elephant egg cells.
However, according to Shapiro, there may be millions of genetic differences between the genomes of Asian elephants and those of mammoths. At best, researchers can only hope to produce an animal with certain mammoth characteristics, rather than resurrecting an extinct species.
As for the dodo, its close relative is the Nicoenas nicobarica, a smaller, more colorful bird found in the Andaman and Nicobar Islands of India; Malay Islands; Solomon Islands; and the Republic of Palau, a western Pacific island nation. But while mammoths and Asian elephants are very closely related (they evolved from a common ancestor 5 million years ago), it's been more than 20 million years since the dodo and Nicobar have any common ancestors.
As a result, the genetic differences between the two birds are much larger, which makes it more difficult to create successful hybrids in the lab, Shapiro said.
In 2022, when Shapiro answered questions from viewers at a Royal Society webinars, she admitted that she and her colleagues had successfully sequenced the entire Dodo genome, which led her to unexpectedly abandon the Dodo bombshell. The study has not yet been peer-reviewed, but Shapiro was taken aback by the excited reaction of the public and the media to her unexpected announcement. The team intends to publish this study in the future.
Reconstructing the dodo genome is not an easy task. First, Shapiro and her team had to find the complete dodo DNA, buried in the bone marrow of Mauritius that had survived for hundreds of years in the warm, humid environment (and possibly tropical cyclones). They then had to distinguish which recycled DNA belonged to the dodo and which belonged to fungi and bacteria that invaded the bones as they broke down.
But this success does not guarantee the resurrection of the dodo. Even with the completely reconstructed dodo genome, researchers still face another major problem: the bird reproductive system.
The eggs produced by mammals are harvested and manipulated by scientists, while the egg cells of birds are tricky. To find and replace the bird egg's DNA, the researchers had to safely and undamagedly locate the egg's microscopic nucleus, which could float anywhere within the giant yolk.
Ben Novak, chief scientist at Revive & Restore, an extinct species conservation group, told Audubon magazine that finding a small packet of genetic material is like "looking for a white marble in a milk pool". As a result, Novak says, it's impossible to create clones by replacing genetic material with altered DNA. In his own study of the extinction of passenger pigeons, the strategy was to alter the gonads of birds. By altering the sperm and eggs produced by the parent birds, the researchers hope to produce offspring with the desired genes.
Even if scientists manage to bring the dodo back to life, the island they once inhabited is now a very different place. Deforestation, invasive species and human habitation will prevent the dodo from reintroducing without major intervention. "If we don't solve the problems that led to their extinction first," Shapiro said, "it might not be worth all the effort and effort to bring them back." ”