The Anthropocene biosphere – William et al. 2015
This article begins by suggesting two prior stages of Earth’s biosphere, the first being defined by microbial life (3.5 to 0.65 Ga) and the later one by metazoan life that was apparent by 650 Ma. Williams et al. discusses that the present state of the Earth is one that indicates movement into a stage of biosphere evolution that the Earth has not yet encountered – one that is defined by four main forcings. These are the homogenization of flora and fauna worldwide, the dominance of Homo sapiens over net primary production and the use of fossil fuels to cause a breach in the energy barrier of the photosynthetic ability of the planet, the anthropogenic selection of traits of other species that drives evolution in a particular direction, and the increased interplay between the biosphere (Earth as it is without human influence) and the “technosphere” – the web of human interaction and our associated technological artefacts and networks. Much discussion on the human impact tends to lean toward the conclusion that humans exist for such a relatively short period of time on Earth that we couldn’t possibly cause change comparable to, for example, a previous mass extinction. This review contradicts this idea by examining the potent possibility that the new relationship between the biosphere and the technosphere will cause changes to Earth significant enough to be relevant on the geological timescale. Such changes have to do with climate, the chemical nature of the ocean, biodiversity, and the fundamental character of Earth’s geology, among many other nuances. William et al. concludes their discussion by comparing the current nature of the technosphere to a parasite that exhausts the potential of the biosphere. They suggest that a future of sustained evolution between the biosphere and the technosphere, a commensal relationship between the two, would require a modification of the current system into one that is more balanced rather than inflated on one side.
Williams et al. Questions
1. How would Homo sapien activity effect the preservation of fossils?
2. In what ways do Homo sapiens influence evolution? Is this beneficial to the biosphere?
3. How can Homo sapiens shift the technosphere from being parisitizing to one that is commensal with the biosphere? ( in other words how can humans produce a technobiosphere?)
Summary of Body Size Downgrading of Mammals Over the Late Quaternary
by Smith et. al
Competition between hominins and animals seems to have occurred from the very beginning of hominin expansion, with large-bodied mammals taking the largest hit. According to the data in this research, megafauna extinction seems to have a relation with hominin migration patterns. This is of importance to the ecosystem, because a decline in megafauna can lead to changes in ecological function. This correlation was found by applying two datasets that encompassed the entire Cenozoic mammal record over every continent, viewed across five important hominin expansion time periods. This included the late Pleistocene, which was the estimated departure of hominins from Africa, to 0.2ka in the future, where they assumed all mammals in the IUCN category would be anywhere between being near threatened to extinct. These data analyses showed a strong and significant size-biased pattern spanning over each continent. This is an important finding because body size and extinction risk have rarely been significantly associated. The data analyses also showed that size selectivity decreased since the end-Pleistocene, which could be reflective of more recently changing natural threats. The loss of biodiversity in the Cenozoic was the most drastic, showing a 10-fold drop in mean and maximum body mass. They also found a hint that homogenization may have been a general consequence of hominin behavior, since Africa was shown to be an outlier in body size and continent size comparisons. It is hypothesized that size-selective extinction will continue within the next 200 years. The extinction of large-bodied mammals showed a change in energy flow in the past, and is predicted to occur again if the future holds more size selective extinctions.
Smith et al. Questions
1. Why would future extinctions be of greater magnitude but reduced size selectivity compared to the past?
2. How have hominins influenced extinction? Has their presence made matters worse?
3. After reading this article, what do you propose is the cause of increased homogenization of ecosystems? Size selective extinctions? Hominin activity?
The Anthropocene biosphere – William et al. 2015
ReplyDelete1. Depends on the activity, but I'm sure we can all agree that humans destroy a lot of nature. Not just by pollution with pharmaceutical runoff and garbage dumping, but harmful gas emissions and non biodegradable products. In addition, I think construction would be a huge one. Blasting, digging, and destroying the environment has probably ended up destroying plenty of fossils. Not only do we break up the areas where the fossils form, but we blast it away and move it before anyone can even check for fossils. We also ruin environments plenty, so there will not likely be many fossils in the future.
2. Humans influence evolution by making it artificial; just look at the hundreds of different dog breeds. Humans interrupt natural selection for artificial selection, making selected species evolve the way that humans want them to. We disrupt the natural order this way. Not only this, but by causing climate change and endangering a lot of animals, we also force the species to attempt to adapt to drastic changes in almost no time at all or face extinction- which, evolution has no set goal, so extinction is what these species face. A species cannot force itself to adapt. Basically, humans ruin everything.
3. In a perfect world where corporations don't exist...green energy. Renewables- wind turbines, solar, wave power, the list goes on. Clean energy would be a drastic improvement for the planet, and it's a start. Along with that, the decrease of methane production from livestock- I've read a few papers on a type of seaweed that decreases methane production from livestock. Decreasing livestock farms altogether would be ideal- not getting rid of them completely, but decreasing. Also stopping deforestation. There's a plethora of things that people could do- unfortunately, money exists, so the planet continues to suffer.
Summary of Body Size Downgrading of Mammals Over the Late Quaternary by Smith et. al
1. Greater magnitude: humans' presence and migration out of Africa, and then evolution into modern humans, has greatly hurt the species on the planet. There will be reduced size selectivity because there are so many ecosystems affected- everything from rhinos to frogs. All species are affected by humans in some way, not just the larger animals. (Not to mention, it tends to be the larger animals who are under a lot of conservation efforts- elephants, rhinos, pandas, tigers, just to name a few that are very popular with the public)
2. I would say with certainty that their presence has made extinctions worse. We haven't been prevalent in the world long enough to really compare our destruction to the destruction of, say, the mass extinctions of the past- but things are definitely worse.
3. The increased homogenization of ecosystems is a tricky one for me. It definitely could have to do with the fact that over the time humans have been here, more and more land mass has had similar use- in most places in the world, you see the same thing: business buildings, housing buildings, landmarks, parks, statues, and so on. These things exist in every culture today, and some species have an easier time adapting than others. The size selective extinctions and hominin activity probably both contribute to this, as events in nature are rarely due to just one thing. It's usually a bunch of factors.
Humans could have effected the fossil record in multiple ways. First, they could have unintentionally "depleted" the fossil record by not leaving body parts like bones laying around to become fossilized. Second, they could have added to the fossil record by having a "kill site" where they brought back all of the hunts to butcher and therefore leaving a plethora of fossils like bones and tools in one specific area. Humans need to understand the role we play on Earth, and fundamentally I believe this starts from the ground up with educating everyone. We cannot fix a major problem if the majority of people do not accept that there is in fact a problem. We are the most intelligent species (well, some of us) to have ever walked the Earth and we have the technology and resources to change our lifestyles for the better. People just need to get on board with it. Future extinctions will not have a size selective aspect to them because we are no longer hunting things to extinction necessarily (with the exception of elephants and other big animals). We are killing them off by destroying and polluting their habitats. It doesn't matter what size you are, if your home and/or resources are gone you will likely follow. We have definitely exacerbated the current extinction rates. It does not matter that the Earth may be in a "warming" part of its cycle, It is the fact that we are increasing this process at an incredibly fast rate and animals are dying because of our actions.
ReplyDeleteWilliams
ReplyDeleteI believe that Homo sapiens activity on the preservation of fossils would act the exact same way that we saw animal scavengers effect fossil preservation. There would be more marks on fossils, more skeleton movement from kill sites, and potentially more larger bones left alone. Just like with the animals, the skeleton remains would be mixed up or lost when Homo sapiens killed something or wanted their body parts for survival objects. This would create a breakage from the environment where that body died and how well the skeleton stays fully intact.
Smith
Hominins have influenced extinctions by both the rate of extinctions and what exactly is going extinct. With added presence of Hominins, the prey that they need to survive will need to increase as the Hominins population starts to grow. This would create a large increase in demands of prey types and make rates of extinctions go up even higher based on the snowball effect with everything associated with the now gone prey. This also leads to a size-selective extinction as well. Hominins have made matters worse with the effects of animal groups lost in environments and that leading to a larger scale of environmental loss wherever their presence is at.
Williams et al.
ReplyDeleteHomo sapien activity could lead to a decrease in the preservation of fossils because many human activities require disturbing the environment, which I believe would make it difficult for dead remains to be preserved. We are constantly building and destroying, making it hard to not only discover new fossils but also to preserve fossils for the future.
Homo sapiens influence evolution through selective breeding of many things, such as flowers or dogs. Humans have been breeding various organisms to select for certain traits and eliminate others for hundreds of years. I don’t know if this evolution is beneficial or not. It almost seems more detrimental to the biosphere than beneficial, with populations of wild animals decreasing and populations of domestic animals forced to be maintained on small areas of land, leading to “human-dominated biomes”. At the same time, human-directed evolution has created (or will be able to create) new species/forms of plants, cyanobacteria, and animals, which could lead us to a better understanding of the intricacies of the biosphere and maybe even an increase in biodiversity.
According to the paper, the technosphere was created by humans with the use of tools that led to an increase in probable survival rates. From there, the technosphere expanded with human inventions such as “roads, mobile (animal) power sources, agriculture…” The paper goes on to state that humans and technology are now interdependent, but that the technosphere acts as a parasite on the biosphere. This is such an interesting way to look at human technology that requires the use of natural materials from the biosphere in order to function. Because of this, I think that the biggest way to make the relationship between the biosphere and the technosphere more commensal is to make human technology reusable. Recycling and reusing materials would prevent finite natural resources from being completely depleted, which should be one of the ultimate goals for humans with regard to our impact on the environment and the biosphere.
Smith et al.
Future extinctions might be of greater magnitude but reduced size selectivity due to different threats faced by animals now. Today, many smaller and specialized animals are endangered due to urbanization of their habitat. As their habitat decreases, the available options to sustain themselves also decreases.
As we’ve discussed for multiple papers, hominins have influenced extinction by creating a size-selective extinction over the Cenozoic. Due to hunting, megafauna and large animals were at a severe disadvantage because of their slow gestation and maturity rates. Populations were not able to match the death rates inflicted on them by hunting, which inevitably contributed to their demise.
Increased homogenization of ecosystems seems to be due to hominin activity. Focusing on humans, we can see that as humans move to new places, they tend to urbanize habitat, which inevitably reduces the biodiversity in an area because it prevents specialized and isolated species from being able to function properly in their niche. If their niche space is gone, then that species will likely not survive.
Humans are definitely having a major influence on the biosphere. Smith et al. focus on the effect humans have had on large mammals, concluding that 125 ka hominins began a process of eliminating large mammals and, in the near future, the largest land mammal will be the domesticated cow. Williams et al. conclude that humans are impacting the biosphere in four categories of influence. Both have indicated that one of the primary effects is homogenization, Smith et al. with size distribution of land mammals and Williams et al. with biodiversity. The cause of this homogenization is simple. Humans alter their environment to suit their needs, and human needs are similar worldwide.
ReplyDeleteThe homogenization of size distribution among land mammals and within the biodiversity of ecosystems, can be interpreted as a function of human population size. One hundred years ago, the human population was 2 billion. Today, it is 7.5 billion and growing. Although we have learned to reason, we have not evolved beyond a very shortsighted approach in our policies. Whether hunting large game for the biggest payoff, using petroleum for fuel and agricultural products, or genetically engineering species to conform to our designs, our policies continue to be concerned with what will be useful in the next four or five years.
It is hubris to assume that we are able to descry the effects of our actions, beyond the immediate future. However, looking at past trends, the result of extinctions, whether mass or background, is an overall increase in biodiversity. Even for catastrophic changes in the biosphere, as was noted by Williams et al. in reference to the Great Oxygenation Event, the result is an explosion in biodiversity. In this, we can view humanity in a broader perspective. Although we are causing extinctions, changing patterns of evolution, and generally wreaking havoc on the planet, we are a small blip in the geologic record. If anyone does look for fossils in the Anthropocene, they are liable to find a very thin section of strata with unusual characteristics.
William et al.:
ReplyDeleteThere are many reasons as to why Homo sapien activity would effect the preservation of fossils. In order to become a fossil, certain things have to take place. You have to die in a certain area and remain undisturbed. Homo sapiens were exploring and moving around, disturbing the environment. It's possible that they could have also dug and not known what they found were of precious value. Humans are definitely influencing evolution. The dogs we have today came from wolves. If you put a wolf next to a chihuahua or a poodle, you can see how they are similar but it is crazy how different they are. I'm not sure if this is beneficial to the biosphere. Wolves are not endangered and neither are dogs. The only thing is some dogs can have problems because of the choosing of certain characteristics and the breeding for those characteristics.
Smith et al.:
Hominins have influenced extinction in multiple ways. In the past, they killed off big game by hunting them. It would make sense to hunt the biggest animal you could find because you could feed the most amount of people, in a short amount of time, with overall less effort. Your payoff would be bigger. The problem is, once you kill off all of the animals, they become extinct and you have to start looking for other animals. Once an animal becomes extinct, it allows other animals to fill up that niche space, which could be both a good and bad thing. The presence of hominins have made extinctions worse. But if we weren't around to cause extinction, something else would have caused it. The problem is, hominins cause extinctions rapidly and cause potential problems for our own kind. An example for today would be the bees. We are causing them to go extinct rapidly, but by causing them to go extinct, we will create mega problems for ourselves in the future.
William et. al- Question 3
ReplyDeleteI feel the issue of preventing humans from living commensally with the biosphere is largely dependent on the unwillingness of many to reduce or cease to use fossil fuels as our main source of energy. Although solar and wind energy are increasing, many are still resistant to use these methods due to an increased cost (installation, weather dependent, etc) . In America in particular, we are so insistent on driving large cars yet most of us don't have a need to drive a truck everyday, and could drive a more fuel efficient vehicle. I think one of biggest changes we could make is better education on this issue of our impact on this planet, and how we are accelerating changes which will greatly impact our environment. Although many people know about "climate change" some believe its something that you either believe in or don't, like it is an issue or morality rather than a proven scientific fact.
Smith et al. - question 2
100% humans caused an impact on extinctions, because before we cared about population sizes/diversity/etc we would hunt things to extinction because we wanted to eat them, and they tasted good. For example, the Dodo is believed to have gone extinct because sailors found that it was easy to catch (flightless) due to being naive to humans and also they tasted good. If an animal presented itself as a reliable food source, early humans would catch it whenever they could without thinking about the impact their hunting was having on population sizes , and once they could no longer find those animals they would move onto some other prey source-- a perk of being omnivorous and at the time, migratory. Many of these megafauna were naive to humans because humans hadn't been present in Asia, Europe, or the Americas (especially) long enough for them to learn that we presented a danger, like animals we hunt now know. Megafauna in Africa likely survived due to being exposed to human interactions longer, and also being around them when they were still developing tool use and advancing their hunting methods so that they were no longer naive to them when humans were more efficient or longer range hunters.
I also think that humans may have consciously targeted the larger carnivores as they may have presented a danger to their own populations, therefore if they had an opportunity to hunt a saber tooth cat to prevent it from later attacking their people, they would .This is possibly more modern day thinking, but i find it no different than more modern humans and decimating wolf and bear populations in order to establish homesteads and ranches with less of a worry about your animals or yourself being attacked.
William et al.
ReplyDelete1. Humans tend to take everything that they think they need, regardless of how the taking damages the earth. They burn the environment to flush out game. They are not sustainable in how they take. They mine minerals, drill for oil, drill for fracking, they dig up, crush, blast, plow, cut through mountains, etc. all to get at things that will result in greater profits.
2. Humans tend to fashion things to their aesthetics, such as domestic animals, plants, and the environment. They pave over the earth, they engineer plants for greater yields, and they selectively breed animals for larger body sizes, greater egg production, and for what they look like or how they behave. This is tailored for human consumption and control, with no regard for the future of the planet.
3. The best way would be to reduce the human population. Other ways would be to utilize power and energy from solar technologies, geothermal energy, wave and current energies, wind energies. Another factor is the trashing of the planet with waste. This can be controlled by consuming less, by less packaging, by recycling, by utilizing less materials such as plastics which do not biodegrade readily. Also, the utilization and waste of pharmaceuticals needs to be reduced and safer ways of recycling or denaturing these chemicals needs to be devised.
Smith et al.
1. The larger animals all seem to have been made extinct, or are now on the endangered species lists. As these larger animals become extinct, the next smaller animals will become the prey of humans with their efficient hunting ways and their need to kill animals for either trophies or for eating. As the larger animals disappear, the next largest ones become the targets.
2. Since hominins appeared on earth, they have migrated over the land, starting in Africa and following many different routes, during different times, to exploit the resources that were available. As prey animals populations were reduced by the efficient methods of hunting that hominins developed, the hominins moved to other areas where either their prey moved or they followed new and different prey animals. This has lead to rapid extinctions of the larger bodied animals, as hunting these could feed many hominins for a time, and was thus an efficient way to sustain themselves. As time passes, more and more of the largest animals have become endangered and have become extinct. This practice has not been curbed by factory farming of domestic animals and will continue to devastate the populations of the larger bodied animals.
3. These are complicated questions. As the number of people on this earth continuously increases, the demand for resources, especially food, increases. What seems to happen in the past, is when the amount of resources decreases, the population of the animals that consume those resources tend to decrease. This may be due to war over the resources, starvation of those not lucky enough to gain access to the resources, or death due to environmental factors related to the destruction and over consumption of the resources. These become serious issues which are fodder for politics, wars, and mass death. The reduction in the world's human population would be a start to begin fixing this in a sustainable way. The reduction in factory farming, industrial mining and drilling for oil and gas, would be another approach. Humans are not programmed to stop reducing their population, nor to stop exploiting the earth's resources for profit. This may lead to the wholesale extinction of the human population. We have not been here for long, and have not evolved much beyond the homo sapiens species. There is little hope that our species will survive. We have not learned much from the past history of the earth.
Smith
ReplyDelete1. Why would future extinctions be of greater magnitude but reduced size selectivity compared to the past?
Future extinctions would be of greater magnitude but reduced size selectivity because of the widespread impact of humans on the biosphere. There would be reduced size selectivity because these ecosystems are somewhat evolved to human interactions and it reaches a plateau.
2. How have hominins influenced extinction? Has their presence made matters worse?
Hominins have influenced extinction by making it a lot more pronounced and occurring faster. Extinctions are occurring faster but don’t have the same exact type of kill mechanisms as extinctions in the past.
3. After reading this article, what do you propose is the cause of increased homogenization of ecosystems? Size selective extinctions? Hominin activity?
I think it is a combination of both. There exists a greater balance between the size balance within ecosystems and the hominin activity have exerted a lot of pressure to ecosystems.
Williams et al. Questions
1. How would Homo sapien activity effect the preservation of fossils?
Homo sapien activity includes massive manipulation of the natural environment. This causes widespread destruction of current systems but also changes in global climate which can make fossil preservation more difficult.
2. In what ways do Homo sapiens influence evolution? Is this beneficial to the biosphere?
Homo sapiens massive and quick influence over ecosystems can perhaps make evolutionary behaviors harder to occur. It is not beneficial to the biosphere.
3. How can Homo sapiens shift the technosphere from being parisitizing to one that is commensal with the biosphere? ( in other words how can humans produce a technobiosphere?)
I think by understanding the way the homo sapien activities have new and pronounced effects on biosphere, a more sustainable technobiosphere can evolve.
Williams et al. 2015
ReplyDeleteI think a major factor as to how humans disturb the preservation of fossils is by continuous alteration of many habitats. Alteration of habitats include expansion of urbanization, drilling for oil or other fuels or alteration of the climate. All of these issues make it incredibly difficult to become a fossil or in general to find “good” fossils. Humans contributed their fair share in the influence of evolution. A few examples are the alteration of plants and dogs. There are countless breeds of dogs that are bred for size, protection of humans or livestock, hunting etc. Plant diversity can also be altered to produce greater energy yields. Overall, the bottom line driving this evolution is human control and it benefiting humans much more than the environment. The best way to make our environment more of a technobiosphere is to utilize the clean and renewable energy techniques. Of course in today’s society getting everybody to do this is a huge problem. A couple of practices gaining much attention today that I think are coming along slowly are solar energy and green energy.
Smith et al.
A reason for future extinction being of greater magnitude with reduced size selectivity is the urbanization of many habitats of smaller animals. As more humans populate and urbanize many areas this would not be favorable for smaller animals. As a result of urbanization driving out of smaller animals, they cannot survive and will ultimately lead to their downfall. Humans have contributed many factors and illustrated many instances in which they influence extinction. For example, if we look at the earliest forms of humans hunting large herbivores they ultimately help drive them to extinction. Unfortunately, matters of this sort are having the same problem today as many large mammals are becoming extinct due to anthropogenic effects. As a result, the loss of large mammals can lead to many changes that negatively affect the environment.
Williams et al.
ReplyDeleteThis article touches on an interesting impact of Homo sapiens on fossil preservation. The authors argue that one effect of the global nature of Homo sapiens and the ease with which we transport our biota, remains and therefore fossils will be preserved in regions whether an organism would have never been normally found. For instance, humans move livestock around frequently, and sometimes even contain livestock in habitats which they would never have been able to survive without the aid of humans. This means the fossil record will show natural remains, but also remains unnaturally transplanted under the influence of humanity. These organisms make up the neobiota, which humans have created.
The overall trend of human influence on evolution has resulted in biodiversity loss. This is partly due to the homogenization of the agricultural industry and corresponding demand for uniformity in crops, both vegetative and in the livestock industry. Earth is no longer a fully natural environment, the authors state, but rather one which in almost all ways reflects the influence of humans on the environment and our modifications on all natural life. For instance, the breeding of agricultural species to target and enhance certain characteristics is reflective now of that organism’s natural evolutionary path, but of an evolutionary path engineered by Homo sapiens.
In order to develop a technobiosphere, the social perception, and consequently interaction, of the environment by humans needs to undergo a shift. The development of many industries, particularly agriculture and energy production must move in a direction which values the preservation of a natural ecosystem and seeks to maintain balance. Large scale social movements would be needed, followed by changes in policy which reflect the value of ecological balance.
Smith et al.
Future extinctions will affect both large and small bodied mammals equally because the threats which mammals face in the modern era are prevalent across all body sizes and are not skewed toward threatening large bodied mammals anymore. Habitat loss is one of the largest drivers of current extinctions, and is not size specific in its impacts, unlike previous drivers such as overhunting in the Pleistocene.
Humans have certainly exacerbated extinction rates and overall contributed to biodiversity loss. The article shows how from the earliest days of hominin expansion, hominins have driven the extinction of large bodied mammals. Currently, human impacts have been well documented as forcing the extinctions of a multitude of organisms, both large and small.
I would argue that size selective extinctions were the result of hominin activity, and that homogenization has overall been an result of human activity starting from the expansion of hominins. Homogenization in current times is heavily practiced in the agricultural and livestock industry, and will likely continue to be practiced as long as it yields its current benefits to humanity.
Williams et al. 2015
ReplyDeleteHomo sapien activity effect the preservation of fossils I think mostly by taking over so much land for cities and places for people to live and work that there isn’t a chance for anyone to find any fossils that may already be forming or already formed in an area. Building a city could easily cover or destroy any fossils that were in the process or already formed, and with the growth of the human population we could possibly take over the whole planet and leave nowhere for fossils to even have a possibility of forming. Homo sapiens also influence evolution by causing climate change so that animals must evolve to be able to survive this change. Without humans these same animals may not have needed to evolve in this way and this could be harmful to the animals because it could cause them to be more susceptible to other dangers that may kill them off. Homo sapiens also have taken over so much land and hunted so much that there have been a lot of extinctions that were caused by man. Humans produce a technobiosphere by first realizing that as humans we are affecting the planet in a negative way and that we need to make the change to save the planet. There are many ways to make this happen like recycling and reducing the amount of waste we produce and using renewable energy like wind and sun.
Smith et al.
There would be less size selectivity compared to the past because of the change in threats that animals face now. There aren’t so many humans going out and hunting for food to survive as there were in the past and because of urbanization, the animals with specific habitats (smaller bodied animals) are seeing more declines because of their habitats being destroyed. Hominins have influenced extinction because they changed how different ecosystems worked because they were smarter than animals. Because of this rise in intelligence they were able to take down animals much bigger in size than them and change how the ecosystem worked. Now with urbanization, it’s not so much about hunting but about taking away to habitats that animals need to live. I believe that the hominin activity is what caused size selective extinctions, the hominins hunted megafauna for more food and because of this we see the decrease in megafauna populations which then led to the homogenization of ecosystems.
Williams et al. Questions:
ReplyDelete1. Human activity may influence the preservation of fossils by the destruction of areas in which they are preserved. The human population continues to expand and therefore, our cities and towns stretch further and further into once untouched areas. Commercial buildings practices may completely disturb and then cover layers of earth that fossils may have been contained in.
2. Humans influence evolution by creating harsher selective forces on species of organisms. Since we have expanded our reach into the natural habitats of all organism on earth, in order to survive other organisms must undergo adaptations that allow them to coexistence with humans. Additionally, the repercussions of our high emissions of CO2 into the atmosphere is beginning to affect marine environments quite drastically; often faster than the organisms could hope to adapt to.
3. I think some drastic changes in how most of the worlds societies function will have to be made. There would have to be a global effort to reduce fossil fuel emissions and other sources of greenhouse gases into the air. Additionally, the structure of cities would have to be kept in mind in order to reduce our expansion into wildlife inhabited areas. More funding would have to be allocated in order to increase the size and maintain wildlife reserves. Efforts to increase the population numbers of endangered species would have to be made as well. Therefore, our techno sphere would have to adapt to be less parasitic to the biosphere.
Smith et al. Questions:
1. Future extinctions of organisms due to humans will be of greater magnitude than past ones, simply because of the expansive reach humans now have in every aspect of the globe. Our technology has changed the atmosphere globally and is now beginning to cause significant shifts in the temperature. This alone poses challenges for a huge amount of species as they are being forced to undergo natural selection in order to thrive in changing temperatures. Additionally, the human population is so large that organisms’ environment all over the world are being encroached upon and severely impacted and therefore, extinctions will be less size selective and of greater magnitude.
Williams et al Paper
ReplyDelete1.Homo sapien activity overall effects the preservation of fossils poorly, as during our early years as species we were most likely scavengers which move and disturb kill remains and more often than true predators, eat or break apart bone to get at marrow and fat. During our middle years as hunters and gatherers we tended to leave good examples of fossils but also traveled a lot into environments which did not lend themselves to fossils often driving our prey there as well. In our later years (today’s time period) our technology and building manipulation will leave many great artifacts for someone else to hopefully discover however as far as fossil preservation goes we again are disturbing everything as we expand to every corner of the globe and dump all our trash and debris in the ocean we are leaving very little to be fossilized by time.
2. Humans influence evolution in almost every conceivable way, as we have tampered with the air every animal and plant breaths and we affects the types of predators that hunt and we affect where and when animals may cross or continue to live amongst our encroaching civilization. This leads to humans exerting unintentional control on almost every aspect of evolution as our very being is changing microbial life and viruses and in turn it just moves up the food chain influencing every aspect of plant and animal development although as I said before we do this unbeknownst to most of us.
Smith et al Paper
1.Future extinctions will be of greater magnitude (ie more species will go extinct) than past ones, because humans and our technology are pouching the Earth further and further off its natural cycle of warming and cooling. This is happening at a rate evolution can not even begin to combat by shedding fur or getting leaner builds, and because of this more animals are in danger of going extinct due to the disturbance in climate becoming even larger. Similar to this but slightly different, is the reason why size selectivity will be reduced as compared to other extinctions correlated with human activity, this is because we are finally running out of the extremes in so far as animal size is concerned. Animals today are generally much smaller than they were in say the Cenozoic and thus do not need vast amounts of room to live in, instead humans are pushing everything together and squeezing as much diversity into as small a body range as possible. In other words both of these statements are true and will become even more correct as humans continue to destroy the environment and climate.
Williams et al
ReplyDeleteHomo would have effected the preservation of fossil human would have been scavenging bones leaving little behind to be fossilized. Humans would have also effected fossilization because as they became more civilized they would have moved animals bodies into possibly less open soil and into micro cities. Homo would have changed evolution by changing the climate faster than normal cycles causing animals to adapt or die off. Also human kill of animals and don't allow them to evolve or pass on genes for future generation to evolve. Until we as humans understand how greatly we are effecting the biosphere we will continue to be parasitic. Once we start to use more renewable resources like solar energy then we will be able to positive impact the environment.
Smith et al
Future extinction will be greater in magnitude because they will be quicker and more dramatic. These extinction will focus more on one specific animal species than on a size selective order or family. Homo has effected extinction by altering environmental and habitats quicker than in the past.
Homo sapien activity can affect the preservation of fossils in a multitude of ways over varying time scales. For example, the anthropogenic alteration of land use and land cover change the environments in which organisms can fossilize. Many animal remains are collected by humans for personal or monetary gain, leading to less material remaining in natural environments to fossilize over time.
ReplyDeleteHomo sapiens influence evolution and extinction events through climate change, selective breeding of plants and animals, destruction of habitats, and a vast array of other impacts are important, as well. Humans present challenges which organisms must adapt to in order to survive, in addition to other influences within their niches like species interactions, competition, etc.
Humans can produce a technobiosphere by reducing the extent to which our technology results in fossil fuel emissions, deforestation, and other negative acts, and instead increasing the extent to which our technology creates a better coexistance. I'm not really sure how that's supposed to happen, but I think that shift is easy to define in general terms, at least.
Smith, et. al.
ReplyDeleteAs outlined in the paper, current species struggling are largely smaller, specialized animals with limited ranges. Given these factors, habitat loss is particularly stressful to their long-term survival. Habitat loss, however, is just one of many ways humans have influenced species diversity, abundance, and extinction. Hunting, mining, agriculture, pesticides, pollution, and the ubiquitous climate change are some of the bigger vectors (of many) as well.
With respect to the homogenization of ecosytems, the paper does a compelling job illustrating a link between the loss of ecosystem diversity and he loss of megafauna that contributed to that diversity, as well as a change (or emphasis) on less-specialized large mammals. It's hard to separate hominim activity from size-selective extinctions (or extinctions in general these days) because we have inhabited (invaded?) every part of the globe and have left some impact, even in the ocean depths where deep critters are showing signs of chemicals working their way down.
Williams, et. al.
Various hominim activities could prevent fossilization, from consumption, using skin or bone as resources, kill sites and/or burial pits that collect them in a way that misrepresents them in some way, all ultimately actions that would prevent remains from being in a position to be fossilized.
The ways hominims have impacted evolution is staggering to consider. The most obvious would be the domestication of animals such as dogs and livestock and even the domestication of plants into more edible forms. As argued in the Smith, et. al., paper, the extinction of megafauna (likely due to the radiation of hominims) impacted ecosystem diversities and their corresponding evolution, pollution has impacted insect evolution, etc. Even behaviorally animals have been impacted by hominim activity, with coyotes and certain monkeys adapting to city environments and and climate change shrinking habitats and exacerbating temporal issues by making seasons less consistent in their duration, forcing some species to migrate to new areas or alter their breeding habits. Whether humans have made matters worse is obviously a judgment call, but from the perspective of the rest of the world, it's hard to argue that we haven't. Certainly human over-population, as with any species over-population, is not sustainable and can only lead to a population crash, it just depends how soon this happens before other things crash, too.
The technosphere is in a difficult place right now. Alternative energy development like wind and solar to mitigate our fossil fuel usage has its own impact, particularly on migratory volant species. A recent article in the New York Times about the impact of self-driving cars indicates a potential direction for technology to mitigate some impact, though, presuming these cars can be programmed to avoid collisions with animals or even route around seasonal habitat corridors. The real test is how much humans want to take these things into consideration and stave off our own decline in the fact of profit and progress.
Humans can have negative effects on fossils preservation because they have changed the surface of the planet by adding cities and roads full of concrete and asphalt. They also negatively effect the direct preservation process by not allowing things to stay undisturbed for long periods of time. Humans have definetly effected evolution by micro managing the environment and even controlling the evolution of certain animals.
ReplyDelete1. Humans cause widespread destruction of natural land environments for numerous different purposes. We drill holes in the earth’s crust, build shopping malls over large stretches of land, and place housing developments where there used to be desert. Even if the remains of an animal was in the optimal location and given enough time to be formed, human influence over the crust of the earth is so extensive that it is likely to never be found, or to be destroyed in the process of some new installation.
ReplyDelete2. One way that humans influence evolution is through the domestication and selective breeding of animals. We take a single type of animal and selectively breed them to exhibit particular traits that we find to be optimal. In this way, we completely alter the genetics of the organism and, in some cases, essentially generate an entirely new species. Rather than letting natural selection run its course, we cause quick, direct alterations to the current and future species pool.
3. By using renewable energy sources, such as wind or solar power, and making efforts to not only rectify the damages that have been caused but also to enforce practices that will benefit the biosphere rather than harm it. We should be focused on reusing, recycling, and cutting down on energy use where it is reasonable.
Williams et al.
ReplyDeleteDo to pollution caused by humans it would be more difficult for material to fossilize. Also due to mines being dug up sediments are constantly being turned over creating a mixture of sediments where fossils may be abundant, and due to shortages of water supplies, and fracking more areas are susceptible of sinkholes. Homo sapiens have influenced evolution greatly by removing some of the natural predators, as well as creating artificial boundaries that may separate some species, or create an environment they have to adapt to. The only way I believe Homo sapiens can shift the technosphere from being parasitizing to one that is commensal with the biosphere is to govern the amount of waste that is produced, because countries such as North America depend so much on technology many of it ends up back in landfills, which is why I think if there was a decrease in waste there could be less environments being disrupted.
Smith et al.
Future extinctions would be greater due to the increase population of humans, and domesticated animals that encroach on larger mammalian habitat. Hominids have influenced extinction through global expansion. This diversification of Hominins targeted high population density driving mammals from their habitat and introducing domesticated mammals that encroach onto wildlife habitat, as well as pouching some species to near extinction, or to extinction. I believe humans have made matters worse.
After reading this article I would have to say that the increase in homogenization of ecosystems is created by Hominins, because we have manipulated the environment to benefit our own personal gains, and interest.
I think Homo sapiens have had an impact on the preservation of fossils from different activities, but I think there is a level of activity we have to think about on how much it affects the fossil preservation. I do think that destroying forests and other habitats for us to build our communities more has definitely made an impact of how fossils are preserved. When this happens, the objects that are in the process of fossilizing are being disrupted because we dig the soil up and change the landscape, effecting how well fossils are preserved.
ReplyDeleteI think hominins have helped in some way with extinction although there are other factors as well. I think in some way having hominins present does make extinction worse, but I don’t think humans are the only cause of extinction so I think it depends on how much we actually do impact the survivability of other organisms. Destroying and changing habitats of animals and also hunting particular animals can definitely have an impact on extinction and I would say that if we had not evolved, the way the world is would be different. I also think about the many eruptions from LIP events and other events that made populations of animals go extinct before hominins evolved which makes me wonder how much of an impact we really have on extinctions but I do agree that we definitely have made an impact of some sort.
Williams et al:
ReplyDelete1. I think Homo sapien activity would negatively effect the preservation of fossils. As we have learned, it can be very difficult to become a fossil because there are certain conditions in which allow something to become fossilized. Homo sapiens change the environment and alter the conditions (pollution, erosion of soil, nutrient cycling, etc.). Also, there is an increasing demand for resources (metals), which causes people to excavate/mine deep into the ground right through layers in which could have fossils/destroy them.
2. Homo sapiens have influenced evolution because they have created new conditions in which forces the native species to adapt/evolve (new traits, specialization, etc.). Homo sapiens also introduced new things (animals, diseases, etc.) in which affected the trophic systems already in place. Also, homo sapiens influence the number of species (hunting) and destroy the habitat of animals (for firewood/other resources). I do think that homo sapien influence can be beneficial and detrimental. It can be beneficial because homo sapiens can drive evolution of species and create new niches (allow invasive species to come in), and overall increase the biodiversity.
3. In my opinion, I think it would be difficult for people today to truly create a technobiosphere in which is not harmful/negatively impacting the biosphere because industrialization is continuously expanding. I think people put themselves/their needs first and will continue to integrate/advance technology rather than focusing on how important the biosphere is to animals and us. I think people need to be more educated about what the future would look like if we didn't have a biosphere and rather had solely a technosphere.
Smith et al:
1. I think future extinctions would be of greater magnitude but reduced size selectivity compared to the past because homo sapiens have evolved and are not as reliant on hunting big mammals for food. I think future extinctions will be of greater magnitude than the past because of the anthropogenic influence humans have on the climate/environment. The rates at which the world around us is changing is occurring a lot faster due to footprint humans have created and animals aren't able to adapt to these changes as fast/takes some species a long time to evolve.
2. Hominins have influenced extinction because they have caused changes in which have influenced what species are present/survive, where they live (habitat), global expansion/introducing new elements, etc. In my opinion, I believe their presence has made matters worse but is not the only factor in which causes species to go extinct.
3. After reading this article, I propose that the cause of increased homogenization of ecosystems and size selective extinctions is due to mainly hominin activity.
Williams et al.
ReplyDelete1.) First, let us remember how difficult it is to become a fossil. To become one, you must die in the right place at the right time, avoid being eaten, avoid being stepped on, and avoid extreme environmental conditions that could prevent preservation and increase degradation. Humans affect all of these criteria. We feed on animals, we alter remains, we destroy natural habitat, and we pollute the atmosphere that can enhance chemical influence on fossilization.
2.) Homo sapiens have a tendency to extirpate species. By annihilating organisms, you prevent their lineage from evolving. However, human may promote evolution because extinctions, driven by their actions, may allow other species to fill the unoccupied niches and allow them to evolve. Whether it is beneficial to the biosphere or not, we will not know until the future. I want to say it is not beneficial, but I cannot give a definite answer.
3.) To prevent parasitism, humans must invest in renewable energy resources, protect and enhance existing fauna, and create bio friendly infrastructure. Technology can help with preservation concerns.
Smith et al.
1.) Technology and human population/distribution are two reasons why future extinctions will be of far greater magnitude. Size selectivity will be reduced because 1.) there are a limited of large game left and 2.) humans are more likely to simply destroy habitats that will, consequentially, impact all animals. The ever growing human population on Earth results in humans urbanizing more land and disturbing more habitats to obtain resources. Technology helps speed up and enhance the distribution of these activities.
2.) Hominins are major factors in extinctions. The expansion of humans around the planet have resulted in the extirpation of many species. They have made matters worse.
3.) I would say humans are the cause of homogenization of ecosystems. We have systematically wiped out an array of species that have been replaced by generalist species that can fill the empty niches. Eventually, we may see ecosystems that have identical flora and fauna around the world.
In my personal opinion, the anthropogenic effects on the environment has been more destructive than the natural effects that were in effect during the last five mass extinctions. humans tend to destroy the areas in which they touch, but that's just my personal opinion. so I think that humans disturb the ability for those animals that have died off from becoming a fossil due to the massive amounts of CO2 as carbon dioxide is very corrosive, which is bad for fossilization. also, human influences in excavating land and the human desire for extracting fossil fuels has definitely decrease the ability in becoming a fossil. when early humans first migrated out of Africa is when the large megafauna started disappearing from the ecosystems.
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