58 Matching Annotations
  1. Aug 2022
    1. Minimum viable population is about 500 individuals, with 1000 to prevent negative genetic drift

      Rule of thumb: 500 minimum viable population, 1k minimum to prevent negative genetic trends (inbreeding).

      Is a similar rule of thumb thinkable for communities of practice in terms of maintaining the community itself, and in terms of keeping it varied / valuable enough on all [[Community building 20100210214508]] aspects Wenger et al list?

  2. Jul 2022
    1. 21:27 - We are just as smart now as we were in the ice age

      Our neurophysiology has not changed much since the ice age. In other words, were an ice age descendent were transported by a time machine and were born in our current era, (s)he would have the same cognitive capacity as a modern human.

      Peter mentions that we came out of our caves and begun agriculture. There is an interesting research paper that hypothesizes that over a period of the last 1.5 million years, human hunters in the Southern Levant successively extirpated the largest species by overshooting hunting over many generations, until the wild fauna population could no longer support human populations, at which point, humans may have turned to agriculture out of necessity. If true, this would support the idea that nonsustainable practices have been with us for a long time and we were out of balance long before Adam Smith wrote about it.

      https://hyp.is/go?url=https%3A%2F%2Fwww.sciencedaily.com%2Freleases%2F2021%2F12%2F211221102708.htm&group=world

  3. bafybeihfoajtasczfz4s6u6j4mmyzlbn7zt4f7hpynjdvd6vpp32zmx5la.ipfs.dweb.link bafybeihfoajtasczfz4s6u6j4mmyzlbn7zt4f7hpynjdvd6vpp32zmx5la.ipfs.dweb.link
    1. Climate is a primary driver of biological processes, operating fromindividuals to ecosystems, and affects several aspects of human life.Therefore, climates without modern precedents could cause large andpotentially serious impacts on ecological and social systems 1–5 . Forinstance, species whose persistence is shaped by the climate canrespond by shifting their geographical ranges 4–7 , remaining in placeand adapting 5,8 , or becoming extinct 8–11 . Shifts in species distributionsand abundances can increase the risk of extinction 12 , alter communitystructure 3 and disrupt ecological interactions and the functioning ofecosystems. Changing climates could also affect the following: humanwelfare, through changes in the supply of food 13 and water 14,15 ; humanhealth 16, through wider spread of infectious vector-borne diseases 17,18,through heat stress19 and through mental illness20; the economy, throughchanges in goods and services21,22; and national security as a result ofpopulation shifts, heightened competition for natural resources, viol-ent conflict and geopolitical instability23. Although most ecological andsocial systems have the ability to adapt to a changing climate, themagnitude of disruption in both ecosystems and societies will bestrongly determined by the time frames in which the climate will reachunprecedented states1

      As climate departure is projected to occur under all IPCC RCP scenarios, this implies profound changes will take place everywhere on the planet.

      The biosphere will react to this unprecedented shift in equally unprecedented ways. Each species has a comfort zone temperature band to exist within. If the temperature falls outside that zone, it can remain in place and adapt, shift geographical location (migration) or go extinct.

      In an ecosystem, species all depend on each other. When a number of these shift their patterns, it will affect the others, increasing total ecosystem disruptions. Since human activity is dependent on nature, this will also ripple up to humans in a variety of ways.

  4. bafybeiapea6l2v2aio6hvjs6vywy6nuhiicvmljt43jtjvu3me2v3ghgmi.ipfs.dweb.link bafybeiapea6l2v2aio6hvjs6vywy6nuhiicvmljt43jtjvu3me2v3ghgmi.ipfs.dweb.link
    1. global biomass of largepredatory fish targeted by fisheries has fallenby two-thirds over the past 100 years (53)

      biomass of large predatory fallen 66% over last 100 years

    2. The global biomass of wild mammalsis now less than 25% of that before the latePleistocene megafaunal extinction—and lessthan 10% that of the world’s current humanpopulation (52).

      biomass of humans exceed biomass of wild mammals by 10-1

    3. On average, large terrestrialmammals have been extirpated from 75% oftheir natural ranges (40)
    1. One of the sad ironies of our time is that we have become very good at studying nature just as it begins to sicken and die under our weight. “Weight” is no mere metaphor: of all land mammals and birds alive today, humans and their livestock make up 96 per cent of the biomass; wildlife has dwindled to four per cent. This has no precedent. Not so far back in history the proportions were the other way round. As recently as 1970, humans were only half and wildlife more than twice their present numbers. These closely linked figures are milestones along our rush towards a trashed and looted planet, stripped of diversity, wildness, and resilience; strewn with waste. Such is the measure of our success.

      As the Tel Aviv researchers who revealed the pattern of progressively overhunting the largest fauna to extinction, then turning to the next largest available fauna noted:

      "We believe that our model is relevant to human cultures everywhere. Moreover, for the first time, we argue that the driving force behind the constant improvement in human technology is the continual decline in the size of game. Ultimately, it may well be that 10,000 years ago in the Southern Levant, animals became too small or too rare to provide humans with sufficient food, and this could be related to the advent of agriculture. In addition, we confirmed the hypothesis that the extinction of large animals was caused by humans -- who time and time again destroyed their own livelihood through overhunting. We may therefore conclude that humans have always ravaged their environment but were usually clever enough to find solutions for the problems they had created -- from the bow and arrow to the agricultural revolution. The environment, however, always paid a devastating price."

      https://hyp.is/go?url=https%3A%2F%2Fwww.sciencedaily.com%2Freleases%2F2021%2F12%2F211221102708.htm&group=world

      It seems humans have a built-in blindspot that prioritizes short term needs over long term survival. History shows us that we are continuously biased towards prioritizing the human environment over the natural one but future generations eventually pay the price for this myopia.

    2. Yet there were still many traps along the way. In what is now Iraq, the Sumerian civilization (one of the world’s first) withered and died as the irrigation systems it invented turned the fields into salty desert. Some two thousand years later, in the Mediterranean basin, chronic soil erosion steadily undermined the Classical World: first the Greeks, then the Romans at the height of their power. And a few centuries after Rome’s fall, the Classic Maya, one of only two high civilizations to thrive in tropical rainforest (the other being the Khmer), eventually wore out nature’s welcome at the heart of Central America.

      Progress traps through history: * 1. Sumerian civilization (Iraq) irrigation system turned fields into salty desert * Greek and Roman empire - chronic soil erosion also eroded these empires * Classic Mayan empire may have collapsed due to the last 2 of 7 megadroughts because it was over-urbanized and used up all water sources, leaving no buffer in case of drought: https://news.harvard.edu/gazette/story/2020/02/new-clues-about-how-and-why-the-maya-culture-collapsed/

    3. Most survivors of that progress trap became farmers — a largely unconscious revolution during which all the staple foods we eat today were developed from wild roots and seeds (yes, all: no new staples have been produced from scratch since prehistoric times). Farming brought dense human populations and centralized control, the defining ingredients of full-blown civilization for the last five thousand years.

      As per the last comment above, Tel Aviv researchers surmise that the progressive extirpation of all the large prey fauna over the course of 1.5 million years forced society in the Southern Levant to innovate agriculture as a means of survival. Our early ancestors did not have accurate records that could reveal the trend of resource depletion so continued short term resource depletion in each of their respective lifetimes.

    4. The first trap was hunting, the main way of life for about two million years in Palaeolithic times. As Stone Age people perfected the art of hunting, they began to kill the game more quickly than it could breed. They lived high for a while, then starved.

      Anthropology and Archelogy findings support the idea that humans began laying progress traps as early as two million years ago. Our great success at socialization and communication that harnessed the power of collaboration resulted in wiping out entire species upon which we depended. Short term success leading to long term failure is a central pattern of progress traps.

      Anthropology and Archelogy findings support the idea that humans began laying progress traps as early as two million years ago. Our great success at socialization and communication that harnessed the power of collaboration resulted in wiping out entire species upon which we depended. Short term success leading to long term failure is a central pattern of progress traps.

      A remarkable paper from Tel Aviv researchers studying early hunters in the Southern Levant as early as 1.5 million years ago revealed that our ancestors in this part of the world were poor resource managers and over many generations, continually hunted large game to extinction, forcing descendants to hunt progressively smaller game.

      Annotation of the 2021 source paper is here: https://hyp.is/go?url=https%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fabs%2Fpii%2FS0277379121005230&group=world Annotation of a science news interview with the researchers here: https://hyp.is/go?url=https%3A%2F%2Fwww.sciencedaily.com%2Freleases%2F2021%2F12%2F211221102708.htm&group=world

      The researchers even surmise that the extinction of game animals by around 10,000 B.C. is what gave rise to agriculture itself!

    1. Prof. Meiri: "Our study tracked changes at a much higher resolution over a considerably longer period of time compared to previous research. The results were illuminating: we found a continual, and very significant, decline in the size of animals hunted by humans over 1.5 million years. For example, a third of the bones left behind by Homo erectus at sites dated to about a million years ago, belonged to elephants that weighed up to 13 tons (more than twice the weight of the modern African elephant) and provided humans with 90% of their food. The mean weight of all animals hunted by humans at that time was 3 tons, and elephant bones were found at nearly all sites up to 500,000 years ago. "Starting about 400,000 years ago, the humans who lived in our region -- early ancestors of the Neandertals and Homo sapiens, appear to have hunted mainly deer, along with some larger animals weighing almost a ton, such as wild cattle and horses. Finally, in sites inhabited by modern humans, from about 50,000 to 10,000 years ago, approximately 70% of the bones belong to gazelles -- an animal that weighs no more than 20-30kg. Other remains found at these later sites came mostly from fallow deer (about 20%), as well as smaller animals such as hares and turtles."

      Progression of body mass over the last 1.5 million years in the Southern Levant: 1) Up to 500,000 years ago 1/3 of bones left behind at Homo Erectus sites belonged to 13 ton elephants that provided 90% of the food. Mean weight of all hunted animals at the time was 3 tons 2) Up to 400,000 years ago, early Neandertals and Homo Sapiens only hunted mainly deer and animals like wild cattle and horse that weighed no more than 1 ton. 3) From 50,000 to 10,000 years ago, 70^ of bones at modern human sites belonged to gazelles weighing between 20 and 30 kg, as well as fallow deer and hares and turtles.

    2. Dr. Ben-Dor: "Our findings enable us to propose a fascinating hypothesis on the development of humankind: humans always preferred to hunt the largest animals available in their environment, until these became very rare or extinct, forcing the prehistoric hunters to seek the next in size. As a result, to obtain the same amount of food, every human species appearing in the Southern Levant was compelled to hunt smaller animals than its predecessor, and consequently had to develop more advanced and effective technologies. Thus, for example, while spears were sufficient for Homo erectus to kill elephants at close range, modern humans developed the bow and arrow to kill fast-running gazelles from a distance." Prof. Barkai concludes: "We believe that our model is relevant to human cultures everywhere. Moreover, for the first time, we argue that the driving force behind the constant improvement in human technology is the continual decline in the size of game. Ultimately, it may well be that 10,000 years ago in the Southern Levant, animals became too small or too rare to provide humans with sufficient food, and this could be related to the advent of agriculture. In addition, we confirmed the hypothesis that the extinction of large animals was caused by humans -- who time and time again destroyed their own livelihood through overhunting. We may therefore conclude that humans have always ravaged their environment but were usually clever enough to find solutions for the problems they had created -- from the bow and arrow to the agricultural revolution. The environment, however, always paid a devastating price."

      This is a fascinating claim with far reaching consequences for modern humans dealing with the Anthropocene polycrisis.

      Technological development seems to have been related to our resource overshoot. As we extirpated the larger prey fauna which were slower moving and able to be successfully hunted with crude weapons, our ancestors were forced to hunt smaller and more agile species, requiring better hunting technologies.

      Agriculture could have been the only option left to our ancestors when there was insufficient species left to support society. This is the most salient sentence:

      "we confirmed the hypothesis that the extinction of large animals was caused by humans -- who time and time again destroyed their own livelihood through overhunting. We may therefore conclude that humans have always ravaged their environment but were usually clever enough to find solutions for the problems they had created"

      This is a disturbing finding as technology has allowed humanity to be the apex species of the planet and we are now depleting resources not on a local scale, but a global one. There is no planet B to move to once we have decimated the environment globally.

      Have we progressed ourselves into a corner? Are we able to culturally pivot and correct such an entrenched cultural behavior of resource mismanagement?

    3. In this way, according to the researchers, early humans repeatedly overhunted large animals to extinction (or until they became so rare that they disappeared from the archaeological record) and then went on to the next in size -- improving their hunting technologies to meet the new challenge. The researchers also claim that about 10,000 years ago, when animals larger than deer became extinct, humans began to domesticate plants and animals to supply their needs, and this may be why the agricultural revolution began in the Levant at precisely that time.

      This is an extraordinary claim, that due to extirpation of fauna prey species, we resorted to agriculture. In other words, that we hunted the largest prey, and when they went extinct, went after the next largest species until all the large megafauna became extinct. According to this claim, agriculture became a necessity due to our poor intergenerational resource management skills.

    4. A groundbreaking study by researchers from Tel Aviv University tracks the development of early humans' hunting practices over the last 1.5 million years -- as reflected in the animals they hunted and consumed. The researchers claim that at any given time early humans preferred to hunt the largest animals available in their surroundings, which provided the greatest quantities of food in return for a unit of effort.

      Our ancestors had a bias to hunt the biggest game. This makes sense from an evolutionary perspective but the unintended consequence of a species with better than average combination of cognitive, toolmaking and collaborative skills was resource overshoot, extirpation and extinction.

      It seems we in modernity are simply repeating ancient cultural patterns of lack of foresight, exasperated by technological sophistication that shortens the cycle time for resource extraction and therefore for extirpation of prey species. Certainly, this is not universal as there are cases where our ancestors did manage resources much more effectively.

    5. A new study tracks the development of early humans' hunting practices over the last 1.5 million years -- as reflected in the animals they hunted and consumed. The researchers claim that at any given time early humans preferred to hunt the largest animals available in their surroundings, which provided the greatest quantities of food in return for a unit of effort.

      This paper suggests our collective propensity for resource overshoot is an ancient cultural trait, not something new.

    6. From giant elephants to nimble gazelles: Early humans hunted the largest available animals to extinction for 1.5 million years, study finds

      Title: From giant elephants to nimble gazelles: Early humans hunted the largest available animals to extinction for 1.5 million years, study finds

      Annotation of source paper preview: https://hyp.is/go?url=https%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fabs%2Fpii%2FS0277379121005230&group=world

    1. Multiple large-bodied species went extinct during the Pleistocene. Changing climates and/or human hunting are the main hypotheses used to explain these extinctions. We studied the causes of Pleistocene extinctions in the Southern Levant, and their subsequent effect on local hominin food spectra, by examining faunal remains in archaeological sites across the last 1.5 million years. We examined whether climate and climate changes, and/or human cultures, are associated with these declines. We recorded animal abundances published in the literature from 133 stratigraphic layers, across 58 Pleistocene and Early Holocene archaeological sites, in the Southern Levant. We used linear regressions and mixed models to assess the weighted mean mass of faunal assemblages through time and whether it was associated with temperature, paleorainfall, or paleoenvironment (C3 vs. C4 vegetation). We found that weighted mean body mass declined log-linearly through time. Mean hunted animal masses 10,500 years ago, were only 1.7% of those 1.5 million years ago. Neither body size at any period, nor size change from one layer to the next, were related to global temperature or to temperature changes. Throughout the Pleistocene, new human lineages hunted significantly smaller prey than the preceding ones. This suggests that humans extirpated megafauna throughout the Pleistocene, and when the largest species were depleted the next-largest were targeted. Technological advancements likely enabled subsequent human lineages to effectively hunt smaller prey replacing larger species that were hunted to extinction or until they became exceedingly rare.

      We must be careful of overgeneralizing sustainable practices to our early ancestors as the evidence from this research shows that we were not always sustainability-minded. In fact, the evidence suggests that when we find the biggest edible prey fauna species, we hunt them to extinction (extirpate) and when they are no longer able to reproduce in sustainable numbers, we move on to the next largest species. In this way, our early ancestors were the first progenitors of progress traps.

    2. We did not find strong evidence to suggest that climate, climatic fluctuations, rainfall, or vegetation over the last 1.5 million years, influenced the size of animals hunted and consumed by humans. Rather, mean body size declined linearly on a backdrop of multiple glacial-interglacial cycles. New human lineages subsisted on smaller prey than their predecessors and used more advanced tools to cope with hunting smaller prey. We suggest that hominins were likely the leading cause of Pleistocene

      The evidence suggests that humans were responsible for extirpating the largest prey fauna at the time, resulting in intergenerational decline in prey fauna body mass.

      This early finding has implications for modern human behavior. In fact, it explains our tendency to overshoot resources until we extirpate them is not a new behavior but one that dates back millions of years. The implications for our current polycrisis suggests we are dealing with an entrenched behavior that may be difficult to change and that technology has amplified our ability to mine natural resources, extirpating them at a faster rate. From this perspective, the Anthropocene can be seen as a logical result of an ever decreasing extirpation rate brought about by increasing efficacy of technological tools for resource extraction.

    3. Levantine overkill: 1.5 million years of hunting down the body size distributionAuthor links open overlay panelJacobDembitzeraRanBarkaibMikiBen-DorbShaiMeiriac

      Title: Levantine overkill: 1.5 million years of hunting down the body size distribution

    1. We emerged from the apelike human phase thanks to fire and language. Together, those advantages made us apex predators: we could learn to hunt and forage from our elders and then gain more energy by cooking the food we gathered. After 200,000 years some of us still live that way, but it was what Lewis and Maslin call a “progress trap.” After modern humans left Africa, they effectively exterminated most of the larger mammals they encountered: the mammoths, giant sloths, sabre-tooth tigers, and countless others. In effect, they overshot their resources.

      Archeologists and anthropologists have evidence to suggest that modern humans were responsible for the extinction of numerous species due to superior predation skills combined with lack of ecological foresight, leading to resource overshoot. This lack of ecological foresight is not a modern phenomena, but goes back to our early ancestors.

  5. Nov 2021
    1. for example arctic char the fish species that's already 00:09:00 all across the arctic region living at its temperature level about 24 degrees celsius in freshwater ecosystems one fraction of a decree further and we 00:09:13 will enter into a cycle of fish death events that will cascade in food security loss of culture and many other things of this keystone species on the aquatic ecosystems for 00:09:25 communities and nature alike

      See Camilo Mora's nature 2013 paper on climate departure:.https://www.nature.com/articles/nature12540

  6. Aug 2021
    1. This is only one example of how we are actively conspiring to bring about climate breakdown. Look at government policies around the world and you will see that we are on course to heat the planet to 3°C by the end of this century. Little of what we love could remain in this future world.

      James Dyke ist einer der Autoren, durch die ich erfasst habe, das Extinction Rebellion eine Antwort auf eine Bedrohung ist, die es in dieser Form noch nie gegeben hat. (Die Klimakrise als Tragödie—zwei Essays – Lost and Found).

  7. Jun 2021
  8. May 2021
  9. Apr 2021
    1. Affinity groups, as they’re often called within the study of social movements, have been a common feature of grassroots political organising in recent years. “We have seen this developing over time, in many contemporary movements – where people are valued for their expertise and what they can bring within the larger movement,” says Bart Cammaerts, a professor of politics and communication at the London School of Economics.
    2. For XR itself, the model seems to have worked, if anything from a numerical standpoint. As academics Douglas McAdams and Ronnelle Paulsenfound in 1993, knowing someone who is involved in social movements is one of the strongest predictors of recruitment into that same movement.
  10. Feb 2021
  11. Jan 2021
  12. Nov 2020
    1. Net zero by 2025 is not physically impossible. There is no real barrier to deploying the technology required or to achieving the necessary changes in behaviour. But to achieve this, it is not a question of physical possibility but rather whether you believe it is possible to change the economic structure and political decision making of the UK (and EU and world) overnight to allow us to deploy all possible solutions over the next five years.
    1. Netto-Null-Ziel müsste also hier schon Ende 2028 oder sogar Ende 2025 erreicht werden. Das entspricht der Forderung der noch recht jungen Umweltbewegung Extinction Rebellion, die im Frühjahr durch spektakuläre Straßenblockaden in London weltweit bekannt geworden ist. „Wenn man 1,5 Grad mit einer Zwei-Drittel-Wahrscheinlichkeit erreichen will und die Feedbackmechanismen des Erdsystems und die größere Verantwortung von Industrieländern berücksichtigt, dann ist das die logische Konsequenz“, sagt Klimaforscher Rogelj.
    1. Our work clearly demonstrates that we already have the tools and technology needed to efficiently power the UK with 100% renewable energy, to feed ourselves sustainably and so to play our part in leaving a safe and habitable climate for our children and future generations.
  13. Oct 2020
    1. In general, while I've been reading Stuart Kauffmann's At Home in the Universe, I can't help but thinking about the cascading extinctions he describes and wonder if political extinctions of ideas like Communism or other forms of government or even economies might follow the same types of outcomes described there?

  14. Sep 2020
  15. Aug 2020
  16. Apr 2020
  17. Jan 2020
    1. generally accepted extinction coefficients for nucleic acids are: • Double-stranded DNA: 50 • Single-stranded DNA: 33 • RNA: 40
  18. Oct 2019
    1. The purpose of this conceptual paper is to provide readers with an opportunity to reassess their work and life in the face of an inevitable near-term social collapse due to climate change.
  19. Feb 2019
  20. Aug 2018
  21. Jul 2018
    1. Physiological plasticity has the potential to buffer organisms from warming by reducing the thermal sensitivity of life-sustaining processes and increasing physiological tolerances (3, 4).

      This is interesting!

  22. Oct 2017
    1. that we owe what ecologists like David Tilman call an ‘extinction debt’ (Tilman et al., 1994, pp. 65–6)—and that this debt will be paid.

      For more on the concept of 'extinction debt'; read this article: http://www.nature.com/nature/journal/v371/n6492/abs/371065a0.html

      Essentially my understanding of 'extinction debt' refers to species becoming extinct in the future because of things that have happened in the past. Tilman refers to the destruction of a species' habitat as the main cause of that species becoming extinct. Makes absolute when I think about it.

  23. Jun 2017
  24. Mar 2017
    1. In a remote, mist-wrapped island north of the eastern tip of Siberia, a small group of woolly mammoths became the last survivors of their once thriving species.

      Love to read about mammoths!