Archive for the ‘(de)extinction files’ Category


The Haast’s eagle (Harpagornis moorei) is an extinct species of eagle that once lived in the South Island of New Zealand, commonly accepted to be the Pouakai of Maori legend. The species was the largest eagle known to have existed. Its primary prey was suspected to consist of moa. This eagle’s massive size may have been an evolutionary response to the size of its prey, as both would have been much smaller when they first came to the island, and would have grown larger over time due to lack of competition (see island gigantism). Haast’s eagle became extinct around 1400, when its major food source, the moa, were hunted to extinction by Maori, and much of its dense-forest habitat was cleared by them.


In some Māori legends, Pouakai kill humans, which scientists believe could have been possible if the name relates to the eagle, given the massive size and strength of the bird. Even normal golden eagles are capable of killing prey as big as sika deer or a bear cub.

Haast's eagle

Before human settlement 700 years ago, New Zealand had no terrestrial mammals, apart from three species of bats. Instead, about 250 species of bird dominated the terrestrial ecosystem. At the top of the food chain was the extinct Haast’s eagle. With a 2.5-3m wingspan weighing in at between 10 and 14 kg, Haast’s eagle was about 30-40% heavier than the largest living bird of prey (the harpy eagle of Central and South America) and was approaching the upper weight limit of powered flight. Haast’s eagle is the only eagle known to have been the top predator in a major terrestrial ecosystem, hunting moa, the giant herbivorous birds of New Zealand, weighing up to 200 kg. Evidence of eagle strikes remain, as holes and rents torn into the bones of moa, which show that the eagle struck from the side, gripped the moa’s pelvic area with one foot, and killed with a single strike by the other foot to the neck or head. The eagle is thought to be the Hokioi of Maori oral history and is recorded in rock art, and artifacts shaped from eagle bone prove that the eagle co-existed with early Polynesians. However, there is no evidence that humans were targets for this huge aerial predator.


In the research paper, New Zealand researchers at Oxford University’s Ancient Biomolecules Center run by Professor Alan Cooper extracted DNA from fossil eagle bones about 2000 years old. Dr Michael Bunce, who performed the research, said, “When I began the research project with graduate student Marta Szulkin, it was to prove the relationship of the extinct Haast’s eagle with the large Australian wedge-tailed eagle. The DNA results were so radical that at first we questioned their authenticity.” The research team demonstrated that the New Zealand giant was in fact related to one of the world’s smallest eagles–the “Little Eagle” from Australia and New Guinea, which typically weighs under 1 kg. “Even more striking was how closely genetically related the two eagle species were. We estimate that their common ancestor lived less than a million years ago. It means an eagle arrived in New Zealand and increased in weight by 10-15 times over this period; such rapid size change is unprecedented in terrestrial vertebrates,” Bunce said.

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New Zealand-based palaeobiologist Dr Richard Holdaway, who was part of the research team and who has studied the eagle for the past 20 years, speculated as to how and why Haast’s eagle grew to be so big, so quick: “The size of available prey and the absence of predators are, we think, the key factors driving the size increase. The large herbivores were available, and after killing a moa, an eagle would have been able to feed unhindered.” Holdaway goes on to say that “it’s great to see New Zealand’s extinct birds the focus of international research. There are so many unanswered questions about our biological past that ancient DNA can address, and the integration of molecular and morphological information can only benefit ecological and evolutionary research.” Research into DNA from ancient moa “poop” and from soil in former petrel breeding colonies is currently underway.


and you shall know them by their trail of artefacts…


As Wiley points out in this paper, even if the lifetime of an interstellar civilization is short; even if they’re all doomed; there is no credible argument as to why they couldn’t create self-reproducing probes (SRPs) to investigate the entire galaxy that, collectively, outlive the originating civilization. This is the very scenario I paint in Permanence. SRPs are a cheaper solution than one-off expeditions. In fact, SRPs are so efficient a solution to exploration and colonization that, plugging in some highly conservative numbers of how many civilizations there might be out there, Wiley shows that hundreds to billions of such probes should actually be here, in our solar system, right now!


In 1981, Frank Tipler put forth an argument that extraterrestrial intelligences do not exist, based on the absence of von Neumann probes. Given even a moderate rate of replication and the history of the galaxy, such probes should already be common throughout space and thus, we should have already encountered them. Because we have not, this shows that extraterrestrial intelligences do not exist.This is thus a resolution to the Fermi paradox—that is, the question of why we have not already encountered extraterrestrial intelligence if it is common throughout the universe.

A response came from Carl Sagan and William Newman. Now known as Sagan’s Response, it pointed out that in fact Tipler had underestimated the rate of replication, and that von Neumann probes should have already started to consume most of the mass in the galaxy. Any intelligent race would therefore, Sagan and Newman reasoned, not design von Neumann probes in the first place, and would try to destroy any von Neumann probes found as soon as they were detected. As Robert Freitas has pointed out, the assumed capacity of von Neumann probes described by both sides of the debate are unlikely in reality, and more modestly reproducing systems are unlikely to be observable in their effects on our Solar System or the Galaxy as a whole.

Another objection to the prevalence of von Neumann probes is that civilizations of the type that could potentially create such devices may have inherently short lifetimes, and self-destruct before so advanced a stage is reached, through such events as biological or nuclear warfare, nanoterrorism, resource exhaustion, ecological catastrophe, or pandemics due to antibiotic resistance.

Simple workarounds exist to avoid the over-replication scenario. Radio transmitters, or other means of wireless communication, could be used by probes programmed not to replicate beyond a certain density (such as five probes per cubic parsec) or arbitrary limit (such as ten million within one century), analogous to the Hayflick limit in cell reproduction. One problem with this defence against uncontrolled replication is that it would only require a single probe to malfunction and begin unrestricted reproduction for the entire approach to fail — essentially a technological cancer — unless each probe also has the ability to detect such malfunction in its neighbours and implements a seek and destroy protocol. Another workaround is based on the need for spacecraft heating during long interstellar travel. The use of plutonium as a thermal source would limit the ability to self-replicate. The spacecraft would have no programming to make more plutonium even if it found the required raw materials. Another is to program the spacecraft with a clear understanding of the dangers of uncontrolled replication.




Early humans living about one million years ago were extremely close to extinction. Evidence from a novel genetic approach, one that probes ancient DNA regions, suggests that the population of early human species back then, including Homo erectus, H. ergaster and archaic H. sapiens, was 55,500 individuals, tops.

Lynn Jorde, a human geneticist at the University of Utah, and his colleagues came to this conclusion after scanning two completely sequenced modern human genomes for a type of mobile element called Alu sequences, which are short snippets of DNA that move between regions of the genome. They shift with such low frequency that their presence in a region suggests that it is quite ancient. Because older Alu-containing portions have had time to accumulate more mutations, the team could also estimate the age of a region.

The scientists then compared the sequences in these old regions with the overall diversity in the two genomes to come up with an ancient census figure of 55,500. (Population geneticists actually calculate the so-called effective population size, which is an indicator of genetic diversity and is generally much lower than absolute population numbers; in this case, the effective population of humanity 1.2 million years ago was 18,500, which Jorde used to estimate the total population number.) The findings appear online in the January 19 Proceedings of the National Academy of Sciences USA.

The small number is surprising because, according to the fossil record, members of our Homo genus were spreading across Africa, Asia and Europe, suggesting that the hominin numbers should be expanding, Jorde says. A major setback must have occurred back then, he thinks, as devastating as a purported super­volcano thought to have nearly annihilated humans 70,000 years ago. “We’ve gone through these cycles where we’ve had large population size but also where our population has been very, very small,” he observes.

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A new hypothesis about recent human evolution suggests that we came very close to extinction because of a “volcanic winter” that occurred 71,000 years ago.
Some scientists estimate that there may have been as few as 15,000 humans alive at one time.

The volcanic winter lasted about six years. It was followed by 1,000 years of the coldest Ice Age on record.

It brought widespread famine and death to human populations around the world. It also affected subsequent human evolution.

The study suggests that at one point there may have been only 2,000 individuals alive as our species teetered on the brink.

This means that, for a while, humanity was in a perilous state, vulnerable to disease, environmental disasters and conflict. If any of these factors had turned against us, we would not be here.

The research also suggests that humans (Homo sapiens sapiens) made their first journey out of Africa as recently as 70,000 years ago.

Estimates of how small the human population became vary but 2,000 is the figure suggested in the latest research.

“This estimate does not preclude the presence of other populations of Homo sapiens sapiens (modern man) in Africa, although it suggests that they were probably isolated from each other genetically,” they say.

The authors of the study believe that contemporary worldwide populations descended from one or very few of these populations.

If this is the case, humanity came very close to extinction.


The really interesting thing about a population bottleneck is the effect it has on evolution. With a small population, mutations get passed through a very large percentage of the species’ members. Detrimental mutations could be devastating and lead to outright extinction. Beneficial mutations, however, could cause fairly fast shifts in the population. And if you imagine some kind of tribal arrangement in which a few dominant males were responsible for a lot of the procreation going on, this situation becomes even more pronounced. An entirely new species might be created within a few generations. Anthropologists have proposed that such bottlenecks were responsible for the rapid development of hominids.

A catastrophe induced bottleneck has another factor affecting evolution. It isn’t just a bottleneck, it’s a bottleneck under pressure. The kinds of dire circumstances that you can imagine would follow a supervolcanic eruption take “survival of the fittest” to a much higher level. Now, that beneficial mutation (say a larger brain that makes it easier to hunt sparse game and build crude shelters) still spreads through a large percentage of the species, but in addition, every genetic line without that mutation dies off (or moves away to somewhere they can hack it). The result: rapid speciation.

Megalania (Megalania prisca or Varanus priscus) is an extinct very large goanna or monitor lizard. They were part of a megafaunal assemblage that inhabited southern Australia during the Pleistocene. They seem to have disappeared between 40,000 and 30,000 years ago. The first aboriginal settlers of Australia might have encountered living Megalanias.


For thousands of years people lived with Australia’s strange and ferocious megafauna like the six metre giant lizard megalania and the marsupial lion. But all these beasts went extinct during the last ice age. In Australia sea levels dropped to 130m below today’s level and deserts spread from 60% to 90% of the continent. Temperatures were 6 degrees colder, it was dry and windy and lasted over 10,000 years. It was the biggest drought ever by experienced by people.


A New South Wales clan tells of Mungoon-gali, the giant goanna, which ambushed people near waterholes. Central Desert tradition has it that Koockard the goanna killed two boys who had teased him, and in the Balgo region of Western Australia’s north they have a story about a goanna that fought a crocodile – and won.” In his book, “The Crocodile that Wasn’t”, Hancock describes a tale from the Nyungar people of southwest Australia that he thinks is about Megalania. In the story, a giant lizard terrorizes a village. The people pray for a solution and 7 dingoes arrive and attack the creature. One bites off its tail and the lizard flees the land. But could this have been Megalania? Megalania is thought to have died out no later than 45,000 years ago. Dingoes are believed to have come to Australia 3,500 years ago. Whether the story is true or not, I’m sure most people today are glad it’s extinct.


Author and Cryptozoologist Rex Gilroy believes that the stories are fresh with the Aborigines because Megalania Prisca has not gone extinct. He relates the story of how the Australian town of Euroa was terrorized by a giant lizard in 1890. The story tells of a 30 foot reptile raiding farms and killing livestock. Many eyewitnesses reportedly saw the creature before it retreated back into the bush.


It has been suggested that, if one were to reconstruct the ecosystems that existed before the arrival of the humans on Australia, it would be desirable to introduce Komodo dragons to represent megalania.