According to Invasive Species Advisory Committee (ISAC), the definition of the invasive species is “a species that is non-native to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health.”
But considering the following facts, why is this species not categorized as an invasive species? Homo sapiens:
is non-native to the most of the ecosystem which it is inhabiting, since it originated from a certain area of Africa and spread quite recently.
has often caused environmental problems by decreasing the local species after its introduction, as it is known that the number of species in the planet is drastically decreasing ever since the advent of Homo sapiens.
is likely to cause the same problem after introduced to new environment where homo sapiens hasn't inhabited yet.
Ignoring for the moment the question of politics, let's consider the various definitions of the term "invasive species" that are in use. Colautti and MacIsaac write in their discussion of invasive species terminology (1):
The greatest confusion [among the discussed ecological terms] surrounds the common term 'invasive' and its various derivatives (Richardson et al., 2000a). Explicit or implicit definitions for 'invasive' include: (1) a synonym for 'nonindigenous' (e.g. Goodwin et al., 1999; Radford &Cousens, 2000); (2) an adjective for native or nonindigenous species (NIS) that have colonized natural areas (e.g. Burke & Grime, 1996); (3) discrimination of NIS established in cultivated habitats (as 'noninvasive') from those established in natural habitats (e.g. Reichard & Hamilton, 1997); (4) NIS that are widespread (e.g. van Clef & Stiles, 2001); or (5) widespread NIS that have adverse effects on the invaded habitat (e.g. Davis & Thompson, 2000; Mack et al., 2000).
Note that except for #2, all the definitions require that the species is a nonindigenous (non-native) species in the area under consideration. Therefore, while humans may be considered to have been an invasive species for much of our species history, under most definitions of the term we no longer qualify because except in a few places (mainly the arctic, antarctic and marine environments, where human presence is minimal) we are now a native species.
See also http://www.smithsonianmag.com/science-nature/are-humans-an-invasive-species-42999965/?no-ist
I don't think there is a good answer.
- Many people and organisations do not even consider Homo sapiens when making such lists. Why? Because we have been for millennia a narcissistic species (think about religious narrative). This is similar to non-scientifically talking about animals. Homo sapiens is usually implicitly excluded from considerations.
- Although Homo sapiens is present on all continents apart from Antarctica, Homo as a genus has been present for millions of years in Eurasia. Homo erectus has been there particularly long. Homo sapiens has outcompeted these species.
- Ecosystems do change. Whether or not Homo sapiens is sufficiently long to be a native species is not a well posed question. Any answer would depend on arbitrary cutoffs. For instance if the first migration of Homo sapiens to Americas happened 14k years ago and it took 20 years per generation, then Americas are populated only for 700 generations. Is it a lot or is it little?
- However, there are places in the world (mostly islands) where Homo sapiens settled very recently. Mauritius was first settled in 1638. And it is clear that since then many bird species (not only the famous dodo) went extinct and most of the area was converted from forests to sugar cane fields and towns. So yes, in this case there is no doubt the migration was recent and that it drastically changed the ecosystem, therefore it fulfils the definition.
- Pragmatism. Probably the most important of it. We define invasive species for a reason: to give them a negative connotation and possibly plan a future removal. Doing these actions against humans are completely different from the legal point.
To sum up: a external observer would classify humans as an invasive species in at least some regions (Mauritius) and not in other (Africa south of Sahara). But people don't classify themselves as such because of political, moral, legal and pragmatic reasons.
Yuval Noah Harari: Why We Dominate the Earth
Why did Homo sapiens diverge from the rest of the animal kingdom and go on to dominate the earth? Communication? Cooperation? According to best-selling author Yuval Noah Harari, that barely scratches the surface.
Yuval Noah Harari’s Sapiens is one of those uniquely breathtaking books that comes along but rarely. It’s broad, but scientific. It’s written for a popular audience, but never feels dumbed down. It’s new and fresh, but not based on any new primary research. Sapiens is pure synthesis.
Readers will easily recognize the influence of Jared Diamond, author of Guns, Germs, and Steel, The Third Chimpanzee, and other similarly broad-yet-scientific works with vast synthesis and explanatory power. It’s not surprising, then, that Harari, a history professor at the Hebrew University of Jerusalem, has noted Diamond’s contributions to his thinking. Harari says:
It [Guns, Germs, and Steel] made me realize that you can ask the biggest questions about history and try to give them scientific answers. But in order to do so, you have to give up the most cherished tools of historians. I was taught that if you’re going to study something, you must understand it deeply and be familiar with primary sources. But if you write a history of the whole world you can’t do this. That’s the trade-off.
Harari sought to understand the history of humankind’s domination of the earth and its development of complex modern societies. He applies ideas from evolutionary theory, forensic anthropology, genetics, and the basic tools of the historian to generate a new conception of our past: humankind’s success was due to our ability to create and sustain grand, collaborative myths.
To make the narrative more palatable and sensible, we must take a different perspective. Calling us humans keeps us too close to the story to have an accurate view. We’re not as unique as we would like to believe. In fact, we’re just another animal. We are Homo sapiens. Because of this, our history can be described just like that of any other species. Harari labels us like any other species, calling us “Sapiens” so we can depersonalize things and allow the author the room he needs to make some bold statements about the history of humanity. Our successes, failures, flaws and credits are part of the makeup of the Sapiens. 
Sapiens existed long before there was recorded history. Biological history is a much longer stretch, beginning millions of years before the evolution of any forbears we can identify. When our earliest known ancestors formed, they were not at the top of the food chain. Rather, they were engaged in an epic battle of trench warfare with the other organisms that shared their habitat. 
“Ants and bees can also work together in huge numbers, but they do so in a very rigid manner and only with close relatives. Wolves and chimpanzees cooperate far more flexibly than ants, but they can do so only with small numbers of other individuals that they know intimately. Sapiens can cooperate in extremely flexible ways with countless numbers of strangers. That’s why Sapiens rule the world, whereas ants eat our leftovers and chimps are locked up in zoos and research laboratories.”
— Yuval Noah Harari, Sapiens
These archaic humans loved, played, formed close friendships and competed for status and power, but so did chimpanzees, baboons, and elephants. There was nothing special about humans. Nobody, least of all humans themselves, had any inkling their descendants would one day walk on the moon, split the atom, fathom the genetic code and write history books. The most important thing to know about prehistoric humans is that they were insignificant animals with no more impact on their environment than gorillas, fireflies or jellyfish.
For the same reason that our kids can’t imagine a world without Google, Amazon and iPhones, we can’t imagine a world in which have not been a privileged species right from the start. Yet we were just one species of smart, social ape trying to survive in the wild. We had cousins: Homo neanderthalensis, Homo erectus, Homo rudolfensis, and others, both our progenitors and our contemporaries, all considered human and with similar traits. If chimps and bonobos were our second cousins, these were our first cousins.
Eventually, things changed. About 70,000 or so years ago, our DNA showed a mutation (Harari claims we don’t know quite why) which allowed us to make a leap that no other species, human or otherwise, was able to make. We began to cooperate flexibly, in large groups, with an extremely complex and versatile language. If there is a secret to our success—and remember, success in nature is survival—It was that our brains developed to communicate.
Welcome to the Cognitive Revolution
Our newfound capacity for language allowed us to develop abilities that couldn’t be found among our cousins, or in any other species from ants to whales.
First, we could give detailed explanations of events that had transpired. We weren’t talking mental models or even gravity. At first, we were probably talking about things for survival. Food. Water. Shelter. It’s possible to imagine making a statement something like this: “I saw a large lion in the forest three days back, with three companions, near the closest tree to the left bank of the river and I think, but am not totally sure, they were hunting us. Why don’t we ask for help from a neighboring tribe, so we don’t all end up as lion meat?” 
Second, and maybe more importantly, we could also gossip about each other. Before religion, gossip created a social, even environmental pressure to conform to certain norms. Gossip allowed control of the individual for the aid of the group. It wouldn’t take much effort to imagine someone saying, “I noticed Frank and Steve have not contributed to the hunt in about three weeks. They are not holding up their end of the bargain, and I don’t think we should include them in distributing the proceeds of our next major slaughter.” 
Harari’s insight is that while the abilities to communicate about necessities and to pressure people to conform to social norms were certainly pluses, they were not the great leap. Surprisingly, it’s not our shared language or even our ability to dominate other species that defines us but rather, our shared fictions. The exponential leap happened because we could talk about things that were not real. Harari writes:
As far as we know, only Sapiens can talk about entire kinds of entities that they have never seen, touched, or smelled. Legends, myths, gods, and religions appeared for the first time with the Cognitive Revolution. Many animals and human species could previously say, “Careful! A lion!” Thanks to the Cognitive Revolution, Homo sapiens acquired the ability to say, “The lion is the guardian spirit of our tribe.” This ability to speak about fictions is the most unique feature of Sapiens language…. You could never convince a monkey to give you a banana by promising him limitless bananas after death in monkey heaven.
Predictably, Harari mentions religion as one of the important fictions. But just as important are fictions like the limited liability corporation the nation-state the concept of human rights, inalienable from birth and even money itself.
Shared beliefs allow us to do the thing that other species cannot. Because we believe, we can cooperate effectively in large groups toward larger aims. Sure, other animals cooperate. Ants and bees work in large groups with close relatives but in a very rigid manner. Changes in the environment, as we are seeing today, put the rigidity under strain. Apes and wolves cooperate as well, and with more flexibility than ants. But they can’t scale.
If wild animals could have organized in large numbers, you might not be reading this. Our success is intimately linked to scale. In many systems and in all species but ours, as far as we know, there are hard limits to the number of individuals that can cooperate in groups in a flexible way.  As Harari puts it in the quotation at the beginning of this post, “Sapiens can cooperate in extremely flexible ways with countless numbers of strangers. That’s why Sapiens rule the world, whereas ants eat our leftovers and chimps are locked up in zoos and research laboratories.”
Sapiens diverged when they—or I should say we—hit on the ability of a collective myth to advance us beyond what we could do individually. As long as we shared some beliefs we could work toward something larger than ourselves—itself a shared fiction. With this in mind, there was almost no limit to the number of cooperating, believing individuals who could belong to a belief-group.
With that, it becomes easier to understand why we see different results from communication in human culture than in whale culture, or dolphin culture, or bonobo culture: a shared trust in something outside of ourselves, something larger. And the result can be extreme, lollapalooza even, when a lot of key things converge in one direction, from a combination of critical elements.
Any large-scale human cooperation—whether a modern state, a medieval church, an ancient city, or an archaic tribe—is rooted in common myths that exist only in people’s collective imagination. Churches are rooted in common religious myths. Two Catholics who have never met can nevertheless go together on crusade or pool funds to build a hospital because they both believe God was incarnated in human flesh and allowed Himself to be crucified to redeem our sins. States are rooted in common national myths. Two Serbs who have never met might risk their lives to save one another because both believe in the existence of the Serbian nation, the Serbian homeland and the Serbian flag. Judicial systems are rooted in common legal myths. Two lawyers who have never met can nevertheless combine efforts to defend a complete stranger because they both believe in the existence of laws, justice, human rights, and money paid out in fees.
Not only do we believe them individually, but we believe them collectively.
Shared fictions aren’t necessarily lies. Shared fictions can create literal truths. For example, if I trust that you believe in money as much as I do, we can use it as an exchange of value. Yet just as you can’t get a chimpanzee to forgo a banana today for infinite bananas in heaven, you also can’t get him to accept three apples today with the idea that if he invests them wisely in a chimp business, he’ll get six bananas from it in five years—no matter how many compound interest tables you show him. This type of collaborative and complex fiction is uniquely human, and capitalism is as much an imagined reality as religion.
Once you start to see the world as a collection of shared fictions, it never looks the same again.
This leads to the extremely interesting conclusion that comprises the bulk of Harari’s great work: If we collectively decide to alter the myths, we can relatively quickly and dramatically alter behavior.
For instance, we can decide slavery, one of the oldest institutions in human history, is no longer acceptable. We can declare monarchy an outdated form of governance. We can decide women should have the right to as much power as men, reversing the pattern of history. We can also decide all Sapiens must follow the same religious text and devote ourselves to slaughtering the resisters.
There is no parallel in other species for these quick, large-scale shifts. General behavior patterns in dogs or fish or ants change due to a change in environment, or to broad genetic evolution over a period of time. Lions will likely never sign a Declaration of Lion Rights and suddenly abolish the idea of an alpha male lion. Their hierarchies are rigid, primal even.
But humans can collectively change the narrative over a short span of time, and begin acting very differently with the same DNA and the same set of physical circumstances. If we all believe in Bitcoin, it becomes real for the same reason that gold becomes real.
Thus, we can conclude that Harari’s Cognitive Revolution is what happens when we decide that, while biology dictates what’s physically possible, we as a species decide norms. This is where biology enables and culture forbids. “The Cognitive Revolution is accordingly the point when history declared its independence from biology,” Harari writes. These ever-shifting alliances, beliefs, myths—ultimately, cultures—define what we call human history.
A thorough reading of Sapiens is recommended to understand where Harari takes this idea, from the earliest humans to who we are today.
 This biological approach to history is one we’ve looked at before with the work of Will and Ariel Durant. See The Lessons of History.
 It was only when Sapiens acquired weapons, fire, and most importantly a way to communicate so as to share and build knowledge, that we had the asymmetric weaponry necessary to step out of the trenches and dominate, at least for now, the organisms we co-exist with.
 My kids are learning to talk Caveman thanks to the guide at the back of Ook and Glook and it doesn’t sound like this at all.
 It’s unknown what role ego played, but we can assume people were not asking, “Oh, does this headdress make me look fat?”
 Ants can cooperate in great numbers with their relatives, but only based on simple algorithms. Charlie Munger has mentioned in The Psychology of Human Misjudgment that ants’ rules are so simplistic that if a group of ants starts walking in a circle, their “follow-the-leader” algorithm can cause them to literally march until their collective death.
Characteristics of homo sapiens
Homo sapiens is the scientific name of our species, human beings. Our species is the last to emerge from the genus Homo, that is, from hominids, descendants of a species of primates that took a different evolutionary course as they descended from the trees and began to walk on their hind legs.
Like the other hominids, our species is characterized by its intelligence capacity that allows it to develop both material tools (from spears and clubs to screwdrivers and revolvers) as well as intellectuals (from spoken language and mathematics to quantum physics and economics), which has allowed him to adapt the world to his biological and civilizing needs, changing the destiny of life on the planet forever. That is why it is the animal species that governs the world today.
The Homo sapiens long we refer to our species with the generic “man”, but this term is deprecated since it is used for adult males, so it is preferred and advised the use of human , humanity or human beings .
What does Homo sapiens mean ?
The term Homo sapiens was assigned by the naturalist Carlos Linneo (1707-1778), author of our method of nomenclature for species, to identify ours as the “wise men”, that is, capable of knowing, of knowing, of deduce, to think in a complex way.
From there comes our self-determination as “rational animals”, capable of articulated language and complex thinking, unlike the rest of the known species.
When did Homo sapiens appear?
The Homo sapiens appears indisputably in Africa, sometime around 315,000 years ago, judging from the oldest remains found on the east coast of Morocco.
However, the oldest samples of modern behavior found in Africa date back 165,000 years ago in South Africa.
However, the species emerged in Africa as an evolutionary step from archaic Homo sapiens or pre-sapiens , so it is estimated that contemporary Homo sapiens (formerly Homo sapiens sapiens ) dates back 40,000 years ago.
Where did Homo sapiens come about?
As we have said, the point of origin of the species is uncertain, and in this respect there are two different hypotheses:
- Polygenism . It assumes that the human being emerged as a species interconnected to Homo erectus , in different regions at the same time, giving rise to various lineages or races. This theory is based on certain scientific findings and many pseudosciences.
- Monogenism . The most scientifically accepted version proposes that the human being arose somewhere in Africa and then migrated to the entire world, giving rise to the various known races or lineages.
How is your zoological classification?
Human beings are eukaryotic and roped beings, like all those who belong to the order of primates, where our closest living animal relatives are today.
In that sense, we come from a primate superfamily known as Hominoidea (hominoids), which contains two families: Hylobatidae (gibbons) and Hominidae (hominids), which in turn is divided into two subfamilies: Ponginae (orangutans) and Homininae , also composed of two tribes: Gorillini (Gorilas) and Hominini (homininos). Finally, within this last tribe there are two genera: Pan (chimpanzees) and Homo (humans).
What are its biological characteristics?
The Homo sapiens is a mammalian species bipedal, whose body has bilateral symmetry, and having sexual dimorphism: Females and males are distinguished by the naked eye by the characteristics of their bodies (women have breasts, small and vulva waists, men they lack breasts, are wider in muscles and have a visible penis).
The upper extremities of the human have prehensile hands with opposable thumbs, which allows him to create and wield tools of various kinds. In addition, its skull has a brain capacity of 1600 cm 3 and has an unparalleled mental capacity in known fauna.
The body of Homo sapiens has an average height of 1.75 meters (men) and 1.62 meters (women) and weighs 75 kg and 61 kg (respectively). Their nutrition is omnivorous and their average planetary life is 71.4 years.
What are its cultural characteristics?
The Homo sapiens is a gregarious species, ie, seeking the company of others. This influenced the development of physical and mental abilities that allow spoken language, being the only animal species capable of communicating through a system of signs and inscribing it to last through various physical supports (writing).
Human societies have hierarchies and social systems that gave birth to politics and jurisprudence, so that our societies can govern themselves through abstract laws taught to future generations, debatable by the community itself and included in codes of laws (constitutions and other holy books).
From early ages, Homo sapiens worshiped nature, imagining in it mythical deities and figures that later gave rise to religion. At present there are three great monotheistic religions and several polytheists, which are disputed between all the faith and the mystical life of the 7 and a half billion human beings that exist.
What are your life stages?
The life cycle of the human being includes a gestation of 9 months that culminates in childbirth. The newborn is helpless and requires paternal care during childhood (up to 12 years).
Subsequently there will be a stage of sexual maturation or puberty (around 15 years old), which culminates with his entry into adulthood in youth (more or less 21 years old).
This will be followed by maturity (shortly before age 40) and finally old age (after age 60).
Where does Homo sapiens live?
The Homo sapiens inhabits the five continents, but focuses the bulk of its population in tropical and equatorial sub bands in the world as well as in temperate zones.
It prefers humid regions such as coasts, regions irrigated by nearby rivers and lakes, and to a lesser extent arid or desert areas.
The most densely populated countries in the world are: China (1,415 million), India (1,354 million), United States (326 million), Indonesia (266 million), Brazil (210 million), Pakistan (200 million), Nigeria (195 million) ) and Bangladesh (166 million).
What subspecies exist?
Formerly the modern human being ( Homo sapiens sapiens ) was differentiated from the so-called neardental man ( Homo neanderthalensis ), when the latter was thought to be a subspecies of ours.
This theory was ruled out, but an alleged subspecies of Homo sapiens whose fossils were found in Ethiopia, in Herto Bouri in 1997 , could be resumed after the discovery of the man of Herto ( Homo sapiens idaltu ) .
Its name incorporates the term idaltu which means “old man”, since the three skulls found would date back 158,000 years.
How did the human being evolve?
The evolution of the human being occurred according to the following stages:
The Aliens Before Us –“We are Not the First Technological Civilization” (Or, are We?)
We live in a universe where matter is distributed in a hundred billion galaxies, each containing a hundred billion stars, made up of quantum fields where space and time are not existent, that manifest themselves in the form of particles, such as electrons and photons, or as waves. Tucked into the 14-billion-year history of this vast observable universe with 100 trillion planets is a pale blue dot teeming with life and a technological civilization created by a strange species known as homo sapiens.
Homo Sapiens –An Aberration or One of Millions of Evolving Beings?
Are we an aberration, an evolutionary accident, or are we one of millions of evolving beings scattered throughout the distant reaches of the cosmos?
In June of 2016, The New York Times attempted to answer this great unanswered question of the human species, publishing an op-ed titled, “Yes, There Have Been Aliens. ”
Extraterrestrial civilizations almost certainly existed at one time or another in the evolution of the cosmos
In a brilliant display of intuition vs evidence, astrophysicist Adam Frank at the University of Rochester and author of “Light of the Stars: Alien Worlds and the Fate of the Earth” , proposed that “while we do not know if any advanced extraterrestrial civilizations currently exist in our galaxy, extraterrestrial civilizations almost certainly existed at one time or another in the evolution of the cosmos. The degree of pessimism required to doubt the existence, at some point in time, of an advanced extraterrestrial civilization borders on the irrational. We now have enough information to conclude that they almost certainly existed at some point in cosmic history.”
10 billion trillion times the universe has run its experiment with planets and life
Frank writes that this probability is not an abstraction, not just a pure number. Instead, he says, it represents something very real: “10 billion trillion planets existing in the right place for nature to have at it. Each world is a place where winds may blow over mountains, where mists may rise in valleys, where seas may churn and rivers may flow. (Note our solar system has two worlds in the Goldilocks zone — Earth and Mars — and both have had winds, seas and rivers). When you hold that image in your mind, you see something remarkable: The pessimism line actually represents the 10 billion trillion times the universe has run its experiment with planets and life.”
The Counter Argument– “We Don’t know whether basic organisms reliably evolve into beings like us.”
Frank’s argument have their appeal, countered Ross Andersen in The Atlantic, but it is an appeal to intuition: “The simple fact is that no matter how much we wish to live in a universe that teems with life—and many of us wish quite fervently—we haven’t the slightest clue how often it evolves. Indeed, we aren’t even sure how life arose on this planet. We have our just-so stories about lightning strikes and volcanic vents, but no one has come close to duplicating abiogenesis in a lab. Nor do we know whether basic organisms reliably evolve into beings like us.”
Evolutionary biologist Wentao Ma and collaborators, observes Frank, used computer simulations to show that the first replicating molecules could have been short strands of RNA that were easy to form and which quickly led to a “takeover” by DNA. And, as neurobiologist and leading expert on evolution of intelligence, Lori Marino has argued, human intelligence evolved on top of cognitive structures that already had a long history of life on Earth. Thus our kind of intelligence should no longer be seen as entirely separated from what evolved before.
“Homo sapiens a genetic accident”
For what purpose did the human brain evolve is a question that has puzzled scientists for decades, and was answered in 2010 by Colin Blakemore, an Oxford neurobiologist who argued that a mutation in the brain of a single human being 200,000 years ago turned intellectually able primates into a super-intelligent species that would conquer the world. Homo sapiens appear to be a genetic accident.
We are the only species of the billions of species that have existed on Earth that has shown an aptitude for radios and even we failed to build one during the first 99% of our 7 million year history, according to Australia National University’s Charles Lineweaver.
A dramatic spontaneous mutation
Genetic studies suggest every living human can be traced back to a single woman called “Mitochondrial Eve” who lived about 200,000 years ago, Blakemore said in an interview with The Guardian. He suggested that “the sudden expansion of the brain 200,000 years ago was a dramatic spontaneous mutation in the brain of Mitochondrial Eve or a relative which then spread through the species. A change in a single gene would have been enough.”
Blakemore stressed that the plasticity that our brains were enhanced with when this mutation occurred. Some scientists, he pointed out, “believe that skills like language have a strong genetic basis, but my theory stresses the opposite, that knowledge, picked up by our now powerful brains, is the crucial mental component. It means that we are uniquely gifted in our ability to learn from experience and to pass this on to future generations.”
The huge and logical downside to Blakemore’s theory is that within a single generation starved of knowledge, thanks to some Six Mass Extinction global disaster, for example, would be cast back to the Stone Age. “Everything, Blakemore observes, “would be undone. On the other hand, there is no sign that the human brain has reached its capacity to accumulate knowledge, which means that the wonders we have already created – from spaceships to computers – represent only the start of our achievements.”
“Universe gets to run the experiment many, many times”
“The universe gets to run the experiment many, many times”, writes Frank. “So if you want to argue Earth is unique, then the onus is on you to show why technological intelligence is so strongly selected against.”
We can’t extrapolate from our existence on Earth, counters Andersen, because it’s only one data point. We could be the only intelligent beings in the universe, he writes, “or we could be one among trillions, and either way Earth’s natural history would look the exact same. Even if we could draw some crude inferences, the takeaways might not be so reassuring. It took two billion years for simple, single-celled life to spawn our primordial lineage, the eukaryotes.
Humans don’t seem like one of evolution’s go-to solutions
“And so far as we can tell, he continued, “it only happened once. It took another billion years for eukaryotes to bootstrap into complex animal life, and hundreds of millions of years more for the development of language and sophisticated tool-making. And unlike the eye, or bodies with legs—adaptations that have arisen independently on many branches of life’s tree—intelligence of the spaceship-making sort has only emerged once, in all of Earth’s history. It just doesn’t seem like one of evolution’s go-to solutions.”
In 2012, Princeton astrophysical sciences professor Edwin Turner and lead author David Spiegel, with the Institute for Advanced Studies, analyzed what is known about the likelihood of life on other planets in an effort to separate the facts from the mere expectation that life exists outside of Earth. The researchers used a Bayesian analysis — which weighs how much of a scientific conclusion stems from actual data and how much comes from the prior assumptions of the scientist — to determine the probability of extraterrestrial life once the influence of these presumptions is minimized.
Their study argued that the idea that life has or could arise in an Earth-like environment has only a small amount of supporting evidence, most of it extrapolated from what is known about abiogenesis, or the emergence of life, on early Earth. Instead, their analysis showed that the expectations of life cropping up on exoplanets — those found outside Earth’s solar system — are largely based on the assumption that it would or will happen under the same conditions that allowed life to flourish on this planet.
In fact, the researchers concluded, the current knowledge about life on other planets suggests that it’s very possible that Earth is a cosmic aberration where life took shape unusually fast. If so, then the chances of the average terrestrial planet hosting life would be low.
“Fossil evidence suggests that life began very early in Earth’s history and that has led people to determine that life might be quite common in the universe because it happened so quickly here, but the knowledge about life on Earth simply doesn’t reveal much about the actual probability of life on other planets,” Turner said.
In conclusion, it appears that the choice between intuition or evidence is yours to make.
[This previously published post has been updated and revised.]
The Daily Galaxy, Avi Shporer, Research Scientist, MIT Kavli Institute for Astrophysics and Space Research. via The New York Times , NPR , The Atlantic , and Rovelli, Carlo. Reality Is Not What It Seems (p. 145) Kindle Edition. Avi was formerly a NASA Sagan Fellow at the Jet Propulsion Laboratory (JPL).
The Galaxy Report newsletter brings you twice-weekly news of space and science that has the capacity to provide clues to the mystery of our existence and add a much needed cosmic perspective in our current Anthropocene Epoch.
Specie vs. Species
Image by Hans via Pixabay
While “specie” also derives from the same Latin root word as “species,” it’s meaning is very different. So what’s the difference between species and specie?
Lexicographers date its appearance to the mid-16th century. It is the ablative of species, as in “form” or “kind,” in the phrase “in specie,” meaning “in the actual form” (source).
Specie is defined as money in coins — specifically, those struck from precious metals instead of printed on paper. The term is most closely related to finance, monetary theory, and banking (source).
To request something “in specie” is to ask for something “in coin” or “in hard coin.” It still has limited legal use as in to request something “in the real” or in the actual form that was specified. It also implies precision or accuracy.
Book review: Creating more effective graphs
Robbins, N.B. 2005. Creating more effective graphs. Wiley-Interscience, Hoboken, NJ. 402 p., including index. [ISBN 0-471-27402-X. USD$64.95 (softcover).]
by Denise Kadilak (Denis[email protected])
Previously published in Technical Communication 52(4):485-486.
Do you need to create a graph? Are you unsure what type of graph will work best with your data? Are you afraid of alienating your readers with an ineffective graph? If so, you may find Naomi B. Robbins’ Creating more effective graphs helpful.
Creating more effective graphs is a quick reference guide on selecting easy-to-read charts and graphs for any context. The book examines a multitude of graphing options in relationship to various data scenarios and briefly explains why some graphs work and others do not.
Robbins, president of NBR, a graphical data presentation consulting and training company, moves her readers from the simple—pie charts, dot plots, and bar charts—to the complex—trellis displays, mosaic plots, and linked micromap plots. The journey is slow and gentle. Robbins avoids large leaps, using a variety of examples at every level and explaining and displaying advantages and disadvantages of one graph type over another. While moving readers through this host of sample graphs, Robbins’ focus—the data—never wanes: Is the data clearly presented? How long will it take the reader to discern the results? Is there a better graphing alternative?
The arrangement of the book mirrors Robbins’ concern for clarity. The book is composed of a series of sample graphs, each accompanied by brief overviews of the data represented and explanations of why one version works better than another. Robbins invites you to take your time, to study each graph and come to some conclusion as to what it represents before turning the page. Once you turn the page, a better graphic representation of the same data usually appears, clearly demonstrating the limitations of many common graphs and the profound affect the choice has on the user’s interpretation of the data.
Influenced by the work of William S. Cleveland and Edward Tufte, the psychology of information design weighs heavily on Robbins’ book. In The visual display of quantitative information (Graphics Press, 1983), a classic on statistical graphics, Tufte argues that a good graphic design allows viewers to quickly comprehend a large array of ideas. Cleveland, in The elements of graphing data (Wadsworth, 1985), argues that the effectiveness of a graph depends on how well you make use of graphical perception principles. Understanding visual and graphical perception is key, Cleveland contends, to creating a user-friendly graph.
Robbins’ examples demonstrate both principles. She repeatedly asks you to time yourself when interpreting a graph, to compare the time it takes to read one graph versus another graph, and to notice if you glean more information from one graph versus another.
For example, when graphing the area of U.S. states, Robbins first uses a strip plot, which displays the distribution of data points on a numerical axis. With the plot, it is easy to discern area range and the location of most of the values. On the next page, however, she displays the same data using a dot plot. The increased clarity of the dot plot is astounding. The dot plot is about three times larger than the strip plot, allowing a good deal more space in which to display all fifty states. Because of the increased space, the dots representing the data do not overlap, making it much easier to see the area.
Of the dot plot, Robbins explains, “Dot plots were introduced by Cleveland (1984) after extensive experimentation on human perception and our ability to decode graphical information. Since the judgments the reader makes when decoding the information are based on position along the common horizontal scale, these plots display data effectively. Since it would be very difficult to fit the names of the states on the horizontal axis, dot plots place them on the vertical axis, and the quantitative variable, area in thousands of square miles, on the horizontal axis” (p. 69).
She takes this same example a step further, demonstrating how to improve on the dot plot by arranging information in order of size rather than alphabetically. She explains, “As in any form of communication, we must know our audience and tailor what we say to be appropriate for that audience, the readers of the chart” (p. 71).
Robbins also offers helpful advice on the various graphing software products available and a checklist of possible graph defects.
The book’s only fault is Robbins’ weak prose style, which affects primarily the preface and introduction. She does well writing short, to-the-point explanations of the various graphs, but the comparatively text-heavy preface and introduction prove awkward for her. Her sentences lack variety, and the excessive use of pronouns with no antecedents makes her writing difficult to understand at times. Fortunately, Robbins’ solid knowledge of her topic and sound visual aids overcome these flaws.
Creating more effective graphs answers all the basic questions of graphing: What constitutes an effective graph? How do I choose a graph? How do I recognize an ineffective graph? Novice and experienced graph designers alike will benefit from reading this book.
Denise Kadilak ([email protected]) is a technical writer with Blackbaud, Inc., a software company in Charleston, South Carolina, and a senior member of the STC Northeast Ohio chapter. She holds a master’s degree in English and is currently working toward a certificate in computer science at The University of Akron.
Homo sapien’s ‘Shadow’ Species –“Hints We May Have Had Story of Evolution All Wrong”
Carl Sagan observed that the frontal lobe of the human brain, comprising more than two-thirds of our brain mass, is where “matter is transformed into consciousness.” Maybe, suggest scientists, we’ve had the story of human evolution wrong: that language evolved before our brains started getting larger (we have brains 3x the size of apes), and language led to brain size increase instead of being a result of it?
An extraordinary discovery in 2017 suggests, perhaps yes , when paleoanthropologists demonstrated that the species Homo naledi existed in southern Africa between 236,000 and 335,000 years ago–potentially the same time that modern humans first emerged in Africa.
This discovery presented a puzzle for scientists, who long held that there was only one species in Africa at this late time period – Homo sapiens.
How did this species exist alongside others with brains three times its size? A 2018 study suggests that naledi’s behavior may have reflected the shape and structure of the brain more than its size.
The small brains of Homo naledi raise new questions about the evolution of human brain size (image above). Big brains were costly to human ancestors, and some species may have paid the costs with richer diets, hunting and gathering, and longer childhoods. But that scenario doesn’t seem to work well for Homo naledi, which had hands well-suited for toolmaking, long legs, humanlike feet, and teeth suggesting a high-quality diet.
According to study coauthor John Hawks, a paleoanthropologist at the University of Wisconsin–Madison. “Naledi’s brain seems like one you might predict for Homo habilis, two million years ago. But habilis didn’t have such a tiny brain–naledi did.”
“Maybe brain size isn’t all it’s cracked up to be,” said Hawks. “It opens the door for us to say that maybe they were more capable than we might assume maybe it isn’t just (brain) size.”
The research shows that the more complex structural features of brains may not solely be a consequence of size, and it suggests that modern humans, Neanderthals and Homo naledi may have a common ancestor.
Tiny Brain Packed a ‘Big Punch’
Homo naledi may have had a pint-sized brain, but that brain packed a big punch. Research by Ralph Holloway and colleagues – that include researchers from the University of the Witwatersrand, Johannesburg, South Africa – published in the Proceedings of the National Academy of Sciences examines the imprints of the brain upon the skulls of this species, called endocasts. The research highlights the humanlike shape of naledi’s tiny brain, surprising scientists who studied the fossils.
Homo naledi endocast (top) with a curvature map (bottom) highlighting the sulci that are visible. The frontal of naledi’s brain looked very human-like despite its small size. (Heather Garvin, Des Moines University).
Hawks and study co-author Shawn Hurst, then at Indiana University Bloomington, presented some of the size and structure data at a meeting in April 2017, but the most recent study includes new comparative data that examines differences between Homo naledi and its Australopithecus cousins — sediba and africanus
In these cousins and in apes, a groove called the fronto-orbital sulcus is visible. In humans and other Homo species, this feature isn’t there, because two neighboring areas of the frontal lobe have expanded, partly covering over another area known as the insula. The best-preserved endocast from Homo naledi also lacks evidence of the fronto-orbital sulcus and mirrors the human form despite its small size.
In these cousins and in apes, reported the University of Wisconsin, “a groove called the fronto-orbital sulcus is visible. In humans and other Homo species, this feature isn’t there, because two neighboring areas of the frontal lobe have expanded, partly covering over another area known as the insula. The best-preserved endocast from Homo naledi also lacks evidence of the fronto-orbital sulcus and mirrors the human form despite its small size.”
Questions a Long-held belief
These findings draw further into question the long-held belief that human evolution was an inevitable march towards bigger, more complex brains.
The Rising Star Caves Fragments
The discovery of Homo naledi by Lee Berger of Wits University Centre for Exploration of the Deep Human Journey and his team at the Rising Star caves in the Cradle of Human Kind in 2013 was one of the largest hominin discoveries ever made and hailed as one of the most significant hominid discoveries of the 21st Century. Berger and John Hawks who was also part of the original Rising Star team who made the naledi discovery, as well as as well as Heather Garvin from Des Moines University in the US , are associated with the Evolutionary Studies Institute (ESI), based at Wits University.
The researchers pieced together traces of Homo naledi’s brain shape from an extraordinary collection of skull fragments and partial crania, from at least five adult individuals. One of these bore a very clear imprint of the convolutions on the surface of the brain’s left frontal lobe.
“This is the skull I’ve been waiting for my whole career,” said lead author Ralph Holloway , of Columbia University.
The anatomy of naledi’s frontal lobe was similar to humans, and very different from great apes. Naledi wasn’t alone. Other members of our genus, from Homo erectus to Homo habilis and the small-brained “hobbits”, Homo floresiensis, also share features of the frontal lobe with living humans. But earlier human relatives, like Australopithecus africanus, had a much more apelike shape in this part of the brain, suggesting that functional changes in this brain region emerged with Homo.
“It’s too soon to speculate about language or communication in Homo naledi,” said coauthor Shawn Hurst , “but today human language relies upon this brain region.”
The back of the brain also showed humanlike changes in naledi compared to more primitive hominins like Australopithecus. Human brains are usually asymmetrical, with the left brain displaced forward relative to the right. The team found signs of this asymmetry in one of the most complete naledi skull fragments. They also found hints that the visual area of the brain, in the back of the cortex, was relatively smaller in naledi than in chimpanzees–another humanlike trait.
Language may have led to brain size increase
“But we did not find asymmetry in the frontal lobe (asymmetry would be if the left and right sides are different) because we didn’t have a skull with both left and right sides of the frontal, not because we looked and it wasn’t there,” said Hurst.
“We’re now studying a more complete skull found later, but we couldn’t determine if there was asymmetry in the Rising Star caves fragments , not that it didn’t have any. Instead we found that the frontal lobe of Homo naledi, despite being similar in size to a chimpanzee frontal lobe, looked like a human frontal lobe in form, particularly in the area where humans produce speech (Broca’s language area),” Hurst told The Daily Galaxy.
“This suggests,” he said, “some sort of language evolved before our brains started getting larger (we have brains 3x the size of apes) and that language may have led to brain size increase instead of being a result of it.
A humanlike brain organization might mean that naledi shared some behaviors with humans despite having a much smaller brain size. Lee Berger, a co-author on the paper, suggests that the recognition of Naledi’s small but complex brain will also have a significant impact on the study of African archaeology.
“Archaeologists have been too quick to assume that complex stone tool industries were made by modern humans,” said Berger. “With naledi being found in southern Africa, at the same time and place that the Middle Stone Age industry emerged, maybe we’ve had the story wrong the whole time.”
Image credit: Top of page,. with thanks to DepositPhotos
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Adam and Eve as the Original Human Couple?
Let’s start with what is often taken to be a major contradiction between the Bible and evolution, namely, God’s creation of an initial human pair (Adam and Eve) in Genesis 2. There are two problems with the common view that this contradicts an evolutionary account of human origins.
The first is that while we often think of the first human pair in Genesis 2 as “Adam and Eve,” the text originally designates them as “the human” (ha’adam) and “the woman” (ha’iššâ). “Adam” becomes a proper name only in Genesis 5:1 and “Eve” is the name given to the woman in 3:20. What are we to make of the fact that the name of the first man is “Human” (’adam) and the name of the first woman is “Life” (havvâ)? And who would name their son Abel (hebel = vapor/futility, the same word that recurs as a theme in Ecclesiastes)? These names are clearly a function of the story (Abel’s life is soon snuffed out). Given the symbolic meaning of the names “Adam” and “Eve,” we may understand the first couple in Genesis 2 as archetypal or representative of all humanity. 4
The second problem with thinking that the picture of the first couple in Genesis 2 contradicts human evolution is that this is not the only account of human origins in Genesis. We need to balance the picture in Genesis 2 with that of Genesis 1, where God creates not individuals, but population groups to fill various niches—including flying creatures in the sky, swimming things in the water, and then animals and humans (designated by the collective noun ’adam) on the land. Christians only read this account of human creation as an original couple because we retroject the account from Genesis 2 back into chapter 1. But we need to respect the different portrayals of creation in each account. 5 In neither case is the text teaching science for then we would need to ask which account is scientifically true? Rather, both accounts teach a harmonious theological vision of being human.
Why is Homo sapiens not categorized as an invasive species? - Biology
Carl Linnaeus (1707-1778) was a Swede who attended Upsalla University, where he became especially interested in the study of plants. It was likely at this time that he began to consider using the sexual parts of the plants as a basis for classifying them. In 1732 he became an official "collector" of specimens for the Academy of Sciences at Upsalla, and made a trip across the norther, arctic part of Sweden (Lapland).
Linnaeus' most famous work was his Systema Natura, the first, rather brief edition of which appeared in 1735. He issued elevent further editions for a total of twelve, expanding each until the work was a massive compilation and more importantly, systematic classification of each species of plant and animal then known to botany and zoology. (Elsewhere, Linnaeus also classified minerals and diseases).
Linnaeus followed two basic principles in the logic of his classification systems:
- Species were grouped into genera (singular: genus), genera were grouped into orders (higher level groupings), and orders into classes. Classes in turn were parts of "kingdoms", of which he, along with his contemporaries and predecessors, recognized three: mineral, plant, and animal.
- Species bore a double (or "binomial" name) -- the first term of which gave their genus, and the second their species.
Linnaeus' great innovation in the classification of plants was to organize them according to the number of their "stamens" (male parts) and "styles" (female parts). The number of male parts determined the class and within a given class, the number of female parts determined the order. Species were well-differentiated types within a genus.
Linnaeus broke new ground in the classification of animals as well. He determined the classes by considering the kind of heart and blood in each, and within each class, the order by a variety of considerations, including whether the animal was born alive or from an egg breathed by gills or lungs and had antennae or tentacles. Here is how this classification looked:
Note: "Worms" (Latin - "vermes") was a general class including real worms as well as all the simple organisms not included in the other orders. This group will be broken up by Lamarck into many orders.
- In the first edition (1735), Linnaeus placed "homo" in the class of "quadrupeds", along with the apes and curiously, the sloth.
- "Europaeus albus" -- white Europeans
- "Americanus rubescens" -- red Americans (native Americans)
- "Asiaticus fuscus" -- yellow Asians
- "Africanus niger" -- black Africans
- He provided a systematic basis for classifying species, along with a system of binomial nomenclature. This achievement is maintained to this day, and species which still bear their Linnean name are marked with the letter "l" in brackets. The reason why species are grouped in common orders, orders in common classes, etc. would be explained only with Darwin's concept of "descent with modification", as we shall see later.
Finally, let's consider Linnaeus' position on the origin of species. Like almost all biologists of his time Linnaeus accepted the "fixity of species" (The exception was Georges Buffon, the French natural historian who intimated that species might evolve, but did not focus on this idea or place it the center of this thought). By fixity of species is meant the following claims: (i) God created each species individually and separately, with the form and functions we now observe today (ii) Each species is perfectly adapted to its environment, with the consequence that none disappear, or become extinct.
The New Wild - Why Invasive Species Will Be Nature's Salvation by Fred Pearce
For a long time, veteran environmental journalist Fred Pearce thought in stark terms about invasive species: they were the evil interlopers spoiling pristine “natural” ecosystems. Most conservationists and environmentalists share this view. But what if the traditional view of ecology is wrong—what if true environmentalists should be applauding the invaders?
In The New Wild, Pearce goes on a journey across six continents to rediscover what conservation in the twenty-first century should be about. Pearce explores ecosystems from remote Pacific islands to the United Kingdom, from San Francisco Bay to the Great Lakes, as he digs into questionable estimates of the cost of invader species and reveals the outdated intellectual sources of our ideas about the balance of nature. Pearce acknowledges that there are horror stories about alien species disrupting ecosystems, but most of the time, the tens of thousands of introduced species usually swiftly die out or settle down and become model eco-citizens. The case for keeping out alien species, he finds, looks increasingly flawed.
As Pearce argues, mainstream environmentalists are right that we need a rewilding of the earth, but they are wrong if they imagine that we can achieve that by reengineering ecosystems. Humans have changed the planet too much, and nature never goes backward. But a growing group of scientists is taking a fresh look at how species interact in the wild. According to these new ecologists, we should applaud the dynamism of alien species and the novel ecosystems they create.
In an era of climate change and widespread ecological damage, it is absolutely crucial that we find ways to help nature regenerate. Embracing the new ecology, Pearce shows us, is our best chance. To be an environmentalist in the twenty-first century means celebrating nature’s wildness and capacity for change.
I give this book 8 out of 10 acorns.
This is a relatively short (190 pages) argument in favour of the idea that we should let nature do it's thing - and that it's thing is to grow and live, and not to maintain what we think of as "primal" ecoscapes. The author backs himself up with 25 pages of footnotes, so you could call it a fairly well researched missive. The book is divided into three parts.
Trying to keep out "invasive" species is, in Mr. Pearce's considered view, a difficult, expensive, and ultimately futile way to manage a wild space. And, he asks, how do we define an invasive species, anyway? Practically any species living on the land that was covered by ice during the last ice age could be considered an invasive species, for example. It all just depends on how far back you want to go. In North America, we generally try to manage our "wild" spaces to try and "restore" them to our understanding of how they were before European contact, but that ignores all the evidence that the people living here before also managed the land to better suit their purposes. So it's not really wild in the sense of "untouched by human hands," even if we manage to erase the impact of the last 600 years. And, it's not really possible, no matter how hard we try - or, in the essential argument of the book - desirable.
Mr. Pearce finds that in the majority of cases, so-called invasive species only become noticeable and a source of concern to people when the environment they "invade" has already been pushed out of balance, and the invasive are simply taking advantage of a new situation in that environment for which they are better suited then the natives. Cited are a number of examples with an invasion receding when the unbalancing force is removed - when pollution has been cleared away, perhaps, often with the help of the invasive species. In a healthy environment, there is usually room for invasive to move in alongside the natives, without causing their endangerment. There is acknowledgment that in certain cases (mostly small islands) an introduced species can and will wreck havoc on endemic species, but, globally, this book finds that the spread and sharing of species will ultimately increase biodiversity, and increased biodiversity strengthens all systems.
There are some interesting anecdotes included in this book - and some political beliefs expressed about the philosophy behind what is presented as a misguided desire to achieve "purity" in ecological preservation that I found a little challenging. And, hopefully, it's found that nature has already fooled us by presenting what we think of as wild untouched jungle, where recent archaeology turns over evidence of past civilizations being actively exploitative, and ultimately, it is presented, that nature can "rewild" areas that mankind abandons sometimes very quickly - not in hundreds of years, but decades. But she does it with invasives.
Despite this book being generally interesting, I did find my mind wandered at times, I didn't find it particularly engrossing as a reading experience. It was also unclear to me what Mr. Pearce intends for his converts to do with their newfound understanding of the invasive plant question - does he want conservationists to simply abandon all attempts to create wild spaces, since there is no true such thing? Or should they/we continue to try and set aside space for nature, but be more permissive as to what we let nature do with it? Or, as people are simply another species on the planet, do we expand our dominion and increase our mingling with the other life of the world with his blessing?
I'm reviewing this book with a giant headache, so I'm probably forgetting to comment on something vital. But you'll have to go read the book to find out.
I give this book 5 out of 10 acorns (for the good science it does contain, which I could simply balance against the good science it ignores).
There is an ongoing debate among biologists, ecologists, gardeners and so about the pros and cons of planting native and non-native species, and opportunistic (also called alien, invasive, migrant, interloping and other pejorative terms) and more “well-behaved” species that are generally safe to plant. These categories are not clearly defined: the boundary between native and non-native is shaky at best (A species present before the last glaciation? One present before human (Homo
sapiens stultus-materfututor) or European colonisation? One that made it without human intervention?) and even a native species may be highly opportunistic under favourable circumstances. I've done my share of rhodi bashing, but very few of the food plants in my garden can be considered in any way native (the imperial powers shifted thousands of species around the world), and many of those can produce volunteers readily, while (native) creeping buttercup (Ranunculus repens), spear thistle (Cirsium vulgare) and broad-leaved dock (Rumex obtusifolius) are an ongoing pain in the arse (not to mention fingers). In my local woodlands native (notably ivy (Hedera helix)) thugs tend to be more of a tendency towards monoculture than introduced species, but ivy is also important habitat – and food – for invertebrates, provided it doesn't choke out everything else.
One of the biggest problems with this debate is that it exists in a space occupied by biology, ecology, culture, economics and politics, some of it dangerously right wing. Even up until relatively recently I would juxtapose the (native) Eurasian red squirrel (Sciurus vulgaris) against the (introduced, bullying, disease-carrying) North American tree rat (S. carolinensis). There are issues with grey squirrels in Scotland, but it's possible to go too far. It can turn into a level of xenophobia that I abhor when directed at my fellow humans. The UK's Environment Agency even uses the same language to talk about signal crayfish (Pacifastacus leniusculus) which has “taken advantage of Britain's welcoming living conditions” and “overstayed their environmental visa”, as that used by the xenophobes and racists at the Border Agency and in the gutter tabloids.
Following a discussion on here about Permie views on invasive plants (see https://permies.com/t/54210/permaculture/Author-unimpressed-permaculturalist-views-invasive), I turned to this book seeking a thoughtful and balanced perspective on invasion biology.
Pearce's thesis is that exotics are an answer to the problem of the changes in land use that humans have been responsible for. There is a strong case for arguing that there is no going back: too many species are gone for ever, and this is a problem that is worsening all the time as we enter the Sixth Great Extinction, a prospect that fills me with existential horror in no way ameliorated by the fact that I understand I'm partially responsible for it.
Part 1 talks about islands, starting with on Ascension Island, where Green Mountain has become an artificial ecosystem to replace the “naked hideousness” that Darwin complained of. To the Permie, Ascension is an example of how a barren site can be converted to a functioning, diverse ecosystem in an exercise in Victorian terra-forming under Darwin's friend Joseph Hooker. It's also a warning: the rats (Rattus rattus) wiped out endemic birds, and the cats (Felis silvestris catus) introduced to control the rats caused more havoc. Equally, the ad-hoc nature of the ecosystem means that many animal species now consume plants unfamiliar in their native habitats. This is juxtaposed, however, with the notorious cataclysm on nearby Gough Island where mice (Mus musculus) have turned carnivorous and seriously damaged an important bird colony in a fashion not to be contemplated before dinner.
It's when he turned to Hawaii that I first became suspicious. He points out that there has been a loss of 66 bird species against 53 gains, with most of the losses hunted to extinction before Europeans arrived. What he doesn't mention is the proportion of these that were endemics: the same applies to the 71 known plant extinctions: the thousand new arrivals exist elsewhere. This, ultimately, is one of the problems. How does one define diversity? The number of species in an area, or the number of species in a wider area, even globally. By Pearce's metric, non-native species have resulted in greater diversity in some places (and he glosses over the examples where this is not the case) by the latter metric, there may be a large number of arrivals, but it's a tendency towards homogeneity, not diversity.
It is possible to make a case that many non-native species, such as rabbits (Oryctolagus cuniculus) in Australia, simply exploit an ecological niche created for them by human activity (in this case in association with sheep (Ovis aries), a woolly maggot also infesting much of Scotland, and bearing partial responsibility for this country's wet desert ecosystems). The same applies, in some places, to water hyacinth (Eichhornia crassipes). The thing about both species is that their massive opportunism may be partly a feature of already disrupted ecosystems, but they would still not be a problem if they weren't there. Non-native species are often scapegoated when the actual problem is more nuanced, but that doesn't change the fact that they are part of that nuance. Pearce tends to gloss over this. Similarly the mesquite (Prosopis glandulosa) fiasco in Africa resulted in winners (such as those selling the wood) and losers (mostly pastoralists). Pearce wants us to forgive the mesquite, and this may be fair, but this struck me as another example of where an introduction favoured those best able to exploit it to the detriment of the already poor.
As I read it became clear that, in order to prove his thesis, Pearce was selecting examples to prove a point: that the problem is not the species itself, but other (typically anthropogenic) influences, or that previously problem species go through a boom and bust. The kind of thing he glosses over is that even if the jellyfish (Mnemiopsis leidyi) in the Black Sea finally do die off, the species they wiped out, that might have otherwise survived, have gone for ever.
Like any good journalist, he's good at pointing out bad science, but like any tabloid hack he's less good at pointing out contrary evidence that counters his thesis. Indeed, he ignores thousands of papers on novel and degraded ecosystems to prove his point. There is certainly a case to make that estimates of extinctions caused by opportunistic species may be based on poor science, or by misinterpretation of good science, but that is not a reason to gloss over very real cases of some opportunistic species being a problem for endemic species. Where there are winners and losers, Pearce ignores the losers, almost as if they didn't matter.
That, needless to say, really pissed me off.
There is another problem with this book. Pearce has a tendency to compare conservation biologists with the worst racists. It's true there is racist language, and some very egregious comparisons, in the whole debate, but sometimes it seems like he's setting up a straw man in order to knock it down. His views on the excesses of the Environment Agency, paid by a succession of more or less right-wing governments, are fair comment, but there is a difference between this and the very real ecological science surrounding opportunistic species. There is some very nasty language being used, but it seems more relevant to separate the very real issues of a minority of opportunistic species from the benefits of an innocuous majority, and that from the racist bollocks of right-wing politicians, gutter tabloids and the gullible people whose fears they stir up. It's very rare that it's the conservation biologists using the derogatory language, but Pearce fails to make that clear. He observes “Many conservationists of the first half of the twentieth century were prominent proponents of eugenics”. True, but the same is true of most journalists of the time. It's true of not a few today, but they tend to be more guarded about it.
The whole book is based on a simple fallacy. He starts from the premise that there are no “natural” ecosystems and conservation is complicated and difficult, and jumps to the conclusion that the solution is that exotics are inherently positive. I'm happy to accept the former, and I'm happy enough to question conservation goals (some aspects of conservation here are highly questionable, perpetuating as they do recently heavily degraded landscapes such as sheep grazing and grouse moor), but I'm not convinced of the validity of the conclusion.
There is some good science behind it. In some circumstances one organism can replace a lost or even extinct one, and this may prove to be an important skill when creating certain types of permaculture habitats, not least forest gardens. Such “ecological fitting” may be just as important as co-evolution. It does not follow that indiscriminate introduction is necessarily always appropriate.
I found this book incredibly frustrating. There are many genuinely important points made by the author. There are some interesting ways of thinking about ecosystems that most people won't have thought of. Many of these have important implications for the way we think about and implement permaculture, in particular forest garden, ecosystems. It's worth reading for that alone. You do need to remember that the law of unintended consequences applies, and be prepared for very thoughtful intervention.
The fact that the author is trying to prove a point rather than present all sides of a complicated discussion badly lets it down. In the final chapter in particular it seems like he's trying to write a rebuttal to George Monbiot (see Feral: Searching for Enchantment on the Frontiers of Rewilding (2013)). Important evidence is deliberately ignored or obfuscated. It's riddled with shoddy logic. This could have been a good book, and Pearce is more than capable of the level of reasoning it would have required. As it stands, it reads like the work of a hack.
The Permie therefore needs to be cautious in what is taken away from this book. It is possible to create a diverse, novel ecosystem that includes many non-native species. The deep flaws in this book gloss over the fact that it's vital that opportunistic species (which should not be confused as synonymous with non-native species) need to be closely monitored and managed. Outside your habitat they can be of ecological benefit, replacing species that are no longer there, or they can do very real damage. In the event of the latter it may be straightforward to trace the culprit, and risk further generalisation, which is to say that permaculture, and not shoddy management, will get the blame.