Present Day Extinctions: Do They live up to the Hype?

The fossil record of the sixth extinction
Plotnick et al. 2016


This paper is about using the fossil record and the IUCN database of current species to determine the expected outcome of the 6th extinction event currently happening. The authors downloaded a list of modern mammal species from the IUCN Red List of Threatened Species. This list had 1250 genera with a total of 5515 species included. They categorized each species as threatened or not threatened  based on their own criteria. Using multiple different fossil databases, they gathered the number of occurrences of these species in the fossil record. In order to have a fossil record, the species had to be listed in one of these databases. These species were divided into four separate groups, depending on a combination of whether they were not-threatened or threatened and had a fossil record or not.
The results of this study illustrated how little of an actual fossil record current biota leave for humans to study.  The authors discuss how each of their various groups only have a small percentage as fossilized record. The authors then go into more detail on each group and illustrate that the more threatened a species is the less likely it will have a specimen in the fossil record, and the same is true for species that are described later in time (the later a species is described in terms of years, the less likely that species is to have a fossil record). Additional aspects which influence fossil record occurrence are geographic range, population density, and body size. Large body size, wide distribution, and small local abundance all correlated with increased preservation potential.
The mammals recorded in the fossil record represent only a small fraction of the animals that we know of today. That being said, the probability of a species at higher risk of extinction becoming a part of the fossil record is about half. Using only the fossil record, the intensity of the “Sixth Extinction” is lesser than that of the Big Five. This led the authors to suggest that more than 75% of current species must be lost in order to match the fossil record of the Big Five. The authors then go on to discuss and critique the various reasons of fossilized preservation of current biological species. For example, the ways a species’ range and body mass influence their likelihood to be fossilized in the first place and found by researchers later on. This then leads to the authors’ conclusion that the fossil record of the last 200 hundred years (rather than the current rates of biodiversity loss) needs to be compared to the fossil record of other mass extinctions in order to fully understand the differences and similarities that exist between the two. This will enable researchers to accurately gauge current biological declines relative to prior mass extinctions and determine whether Earth truly is undergoing a mass extinction event.
Questions:
  1. Is it worth to do studies such as this one even though the fossil record is so incomplete?
  2. Why would large size, wide distribution, and small local abundance increase the preservation potential of an animal? Which of the three factors discussed (large size, wide distribution, small local abundance) do you believe increases preservation potential of a species the most?
  3. Do you believe small local abundance intrinsically increases a species’ preservation potential, or rather is an attribute which frequently is associated with large bodied animals?
  4. Is ‘Pull of the Recent’ a significant obstacle to overcome when scientists compare ancient extinction events with modern biodiversity declines? Do you believe that fossil representatives of modern species need to be taxonomically revised because of this?
  5. When paleontologists from 40017 are excavating soils dated to 2017, what do you think some striking characteristics of fossils discovered will be, perhaps in relation to fossils of the Cenozoic era?

Comments

  1. 1. I do believe that studies like this should be done despite the limited fossil record. The advantage of studying current extinctions is that since we have living populations of endangered species information about the characteristics of the current extinctions can be made without having to rely heavily on the fossil records.
    2. I think that wide distribution would most likely influence the preservation potential for an organism the most. This is because the environmental factors have to be just right for fossilization to occur and having a wide distribution would increase the probability of the organism dying in the right environment to be preserved in.

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  2. Large size, wide distribution, and small local abundance would increase the preservation for an animal because it adds protection to the animal’s skeletal preservation by having lots of different environments to properly preserve the fossils. The most important would be a wide distribution since this allows the animal to preserve in multiple areas with different environmental factors, which may include settings that are just right to keep the skeletal remains intact. This could be areas with less scavengers or weathering, but many different skeletal sites can add to the chances of the preservation potential for this animal or species.

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  3. We should absolutely keep doing studies like this. I think it is incredibly important to see what is happening currently to animal populations and what will cause them to go extinct. I would say that a wide distribution is more important when it comes to preservation. The larger area they inhabit the more easily they can move due to disturbance. I don't think by 40017 there will be any more fossils to find if we keep up discoveries at the rate we are today. Plus, we are preserving current extant animals in museums and collections. They may find absurd amounts of chemicals and radiation though.

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  4. I think any study is worth doing. If nobody did a study or looked into something that other people thought was controversial, stupid, or worthless, we wouldn’t have much to go on as a species. People learn differently, leading them to develop different perspectives and sometimes new ideas about the same set of information. Even though the fossil record is tricky, scientists would never use it at all if there was nothing more to learn.
    I think wide distribution is the most significant factor for animals mentioned in this question. We have been shown that large size is not always helpful, and small local abundances may be inefficient for overall maintenance of a species if range is smaller.
    I have a feeling that most of the record people will find in the future will be archaeological and only minimally organismal. We have degraded habitats and enacted so much land cover change that I’m not certain organisms have the time and space to fossilize uninterrupted by human activity. If the fossil record of Earth’s history is minimal, I would guess that future paleontologists, if there are any future paleontologists, will find an even smaller record of non-human species than we have found for past years.

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  5. I believe that it is worth doing studies such as this one. I think any study leads to an increase in information or understanding of whatever is being studied which can only help us to learn more. I also think that even though the fossil record is so incomplete, doing studies like this allow us to learn more and fill in more information that we do not know already. I think that wide distribution increases preservation potential of a species the most because if there is a wider distribution of organisms, it’s more likely that this organism will be preserved somewhere within the wide distribution because of different environmental factors that would occur in the distribution. I think that ‘Pull of the Recent’ may be an obstacle to overcome when scientists compare ancient extinction events with modern biodiversity declines, but I also think that all the recent organisms did evolve these past organisms, so I don’t think it is a significant obstacle. I believe that in 40017 there will be very minimal, if any at all, fossils left to find by paleontologists. I also think that with urbanization and the large human population size that continues growing that there won’t be anymore land that will have the necessary aspects needed to create fossils, so any present-day organisms will likely not leave any fossils for future paleontologists to find.

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  6. 1. Most (if not all) studies are worth doing. Even though the fossil record is so incomplete, it still exists and gives us a lot of information. While it may not tell us everything about the potential 6th mass extinction because of the different factors influencing it, the more information we have, the better.
    2. I think that wide distribution would preserve a species the most. Being crammed into a small area certainly does not help a species, and a wide distribution helps the species thrive by giving more area covered. Not only that, but it protects them from dying off completely if an area undergoes a disaster- the other populations would be relatively safe.
    3. It is hard to say if small local abundance increases a species' survival potential.
    4. It is an obstacle, but not a catastrophic one.
    5. I don't think humanity will last this long with this political climate, but theoretically, I think some of the characteristics of fossils will be how polluted they are.

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  7. 1. Yes I think it is worth to do studies as this one even though the fossil record is so incomplete because more information is always better. This also emphasizes the need to increase the fossil record but also rely on other information/technology to "fill in the gaps".
    2. I think these factors (large size, wide distribution, and small local abundance) would increase the preservation potential of an animal because: large size could take it longer to degrade/more time to allow remains to be fossilized, wide distribution could have the remains once an animal dies in perfect conditions to be preserved if the animals move to wide ranges, and small local abundance can give an advantage to a species/less competition. I think wide distribution increases preservation potential of a species the most because it allows species to move to areas/avoid changes in their environment which can make them go extinct, find new habitats, and can be in areas where fossilization easily occurs.
    3. I believe it is hard to say for sure whether small local abundance has a significant affect on increasing the survival of a species.
    4. Yes, ‘Pull of the Recent’ is a significant obstacle to overcome when scientists compare ancient extinction events with modern biodiversity declines. I do believe that fossil representatives of modern species need to be taxonomically revised because species are being driven to extinction from human anthropogenic factors instead of the mechanisms which caused extinctions in the past.
    5. When paleontologists from 40017 are excavating soils dated to 2017, I don't think there will be much of anything to be fossilized because a lot of species will be extinct and with increase in urbanization/infrastructure (with increasing population of humans), many fossils will be destroyed/built over to find.

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  8. I do think doing studies like this one is important no matter what the fossil record looks like. I think it still gives insight on what other extinctions could happen in the future or it could just give information that will be important for later use. Large size, wide distribution, and small local abundance increase the preservation potential of an animal because there are certain aspects that allow for a fossil to be made and changes in how many animals and their size can have better preservation than smaller animals as there is more to preserve. I think wide distribution would be the main factor of this increase in preservation potential as animals have a larger distribution; they have more area that may be better for fossil making, the environment plays a significant role in how things are preserved.

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  9. I do think it is important to do studies such as this one even though our fossil record is incomplete. We are still able to gain valuable information even though there are some gaps in the record. Both large size and wide distribution would be very important for increasing the preservation of an animal. I think the most important factor is wide distribution because there will be more areas for the animal to become properly preserved in. I do not think that small local abundance is increasing species preservation. In future research I do not believe that were will be many fossils left to find. Since we have advanced technology we are finding fossils quicker than ever which will leave less for future generations.

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  10. I believe producing a study like this is absolutely important! If we did not generate these types of studies, it would be difficult to analyze current species extinctions and what factors might be causing them to be going extinct. The data encompassed in these types of studies can provide us with a foundation to future and maybe more improved studies. As far as the mentioned aspects to preservation of species, I believe wide distribution is the most important factor. This is because animals would not be confined to one specific area which may or may not have the correct factors for becoming a fossil. If the animal can move around it has a higher chance of becoming fossilized under the right conditions. If an animal is in a small local abundance, I believe this may or may not help its chances to be preserved. I think many factors would need to be considered including if it can be found, if it had died in a good place and if hard body parts. If they did die in the right place having an abundance in a local area would seem to give them a higher chance of being found. By the year 40017, I believe fossils may be hard to come by. Humans are drastically changing the composition of the environment which is going to make it difficult for future soil excavators to find any recent or historical fossils.

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  11. When comparing the Big 5 to the current extinction event, “pull of the recent” is not so much an obstacle as a consideration for determining extinction rates. Because we rely on morphology, for identifying taxa that went extinct in deep time, they are necessarily grouped into higher categories, i.e., family and order. That fewer fossils survive, the further back in time we look, will result in some skewed data for past extinctions. Modern taxa can be categorized into species and subspecies, by examining genomes, behavior, physiology, as well as morphology. It is easy to recognize an elephant. When a similar animal is found in the fossil record, we’ll say it’s in the same family. Because they are recent animals, it is more likely that we’ll find one in the fossil record than an animal that lived 400 million years ago. Accounting for these phenomena, we can make a reasonable comparison between the current extinction event and past ones.

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  12. I feel like it is difficult to compare the fossil record of the last 200 years to the previous mass extinctions because of the massive urbanization and habitat degradation we are responsible for. Previously humans were not in the way or influential of what and what didn't become a fossil, but i would guess that the ability to become a fossil is increasingly difficult in the Anthropocene, as we have take up a large portion of open spaces, but also we hunt and poach for commercial gain, therefore what actually makes it into the fossil record wouldn't necessarily be reflective of real life. Nevertheless, i still feel that studies such as these are important to understand our impact on our environment and how we are perhaps pushing nature into a larger extinction rate than would be naturally occurring had we not existed.

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  13. Question: "Why would large size, wide distribution, and small local abundance increase the preservation potential of an animal? Which of the three factors discussed (large size, wide distribution, small local abundance) do you believe increases preservation potential of a species the most?"
    As we have learned in class and when looking at this paper we can understand that animals that are more globally spread with large numbers not only increase their chances of survival, but also are more likely to become a fossil. If the entire population of an animal species are gathered in a small local area then the chances for survival decrease.

    Question: "When paleontologists from 40017 are excavating soils dated to 2017, what do you think some striking characteristics of fossils discovered will be, perhaps in relation to fossils of the Cenozoic era?"
    The fossils found 38,000 years from now from the present year will be much different than the fossils that we are currently excavating from the Cenozoic era. There will be more artifacts found than fossils I think. Cars, computers, cell phones, etc. are all things that someone may dig up one day. I think that there will definitely be human fossils found but maybe not as many as we would think due to the complicated process of becoming a fossil.

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  14. 1) Yes because even thought the record is complete we can still estimate the past population and see extinction patterns. Even though it might not be as accurate it is still a good source to give us a general idea.

    2) Large size is usually correlated with distribution and this would make it so if something happens in one area and kills off that group you still have species reserves elsewhere. Small local abundance can make it to where the species is able to maintain their population more easily. I think that wide geological range is most likely to protect a species the most as it allows for many reserves for a species and the chance of evading localized environment events.

    3) I feel it is associated with larger animals as larger animals do require more resources and as a result only a few member are able to live in one area.

    4) I think this is a real problem as we do have more data for recent event rather than past events. I think this does need to be taken into consideration when making comparisons as low data quantities can lower the accuracy of the finding. The modern species might have to be revised as because of species evolving, but the current record is sufficient for now.

    5) I think the modern mummified movement might increase the number of true body fossils, how ever I think locating the fossil will be easier as we have increased the about of debris present. But these fossils might be destroyed due to human modification of the landscape. For the most part I believe the number of fossils will be well preserved and abundant in places that do not participate in cremation.


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  15. Plotnick et al.
    I believe that it is important as any information leading to how to handle what humans are doing to the environment and what will happen if we continue to pursue our current courses of action are key to our survival.
    The larger the size, the more likely something will be left some where, the wider the distribution - the more likely the organism will be in a place to become a fossil, with small local abundance the animal is scattered across the landscape.The wider the distribution of an organism is the most important of these factors. Small local abundance is associated with large body size, as a specific locality can only support so many large bodied animals.
    Yes, I do think that 'Pull of the Recent" is an obstacle, as it involves lumping fossils with familiar, recent fauna, not taking into account living species or subspecies. This confuses and blurs things, creating one large mess. In some cases the record needs to be revised due to modern species, not all.
    I'm not sure what they will find, but it will be heavily interspersed with plastics, and non-biodegradable materials. Our trash middens (landfills) and the oceans are filled with such stuff. I think that if we survive to this point, the soils will have been poisoned and they will wonder how we survived at all. They will wonder where a lot of the bones of eaten animals came from and how they were transported, or if they grew in these areas. Here in the desert, we eat things like oysters, clams, etc. and throw away the shells. We eat meat from cattle and lamb grown in South American rainforests, and in New Zealand. We also have seeds and plants which have been grown for food and decoration that are better suited for other places. They will wonder what our ecosystem was like to raise this kind of food and decorations.

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  16. I think that it is worth it to look into the fossil record even though it is largely incomplete for studies like this. A better understanding of the patterns of extinction can surely help, even if it is a small amount. Knowing more in general about extinction patterns and being able to create estimates on what may happen can be helpful in determining plans to help prevent extinction of endangered species. I believe that wide distribution of a species is most important in increasing preservation potential, because the probability of the animal being in an area where fossilization occurs could be higher.

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  17. I do believe that although limited fossil records are found these studies may help fill gaps that may occur if we wait until we assume there are adequate amounts of fossils to be studied, because if certain species do not fossilize correctly, or become disturb then we will end up losing any remnants of a species. I think being large, and widely distributed animals would increases the chances of an animal being preserved, because there is a higher chance of finding a complete fossil, as well as, a higher chance that a larger fossils would still have its skeletal structure intact.

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  18. I do believe that it is still worthwhile to analyze the fossil record even if it is incomplete, because any addition of data can be helpful when attempting to determine the big picture. Although it will not provide researchers with an overall answer, that is typically the case for a lot of analytical studies. By analyzing what data we do have, we can begin to estimate where there are gaps and form new questions based on the data combined with knowledge that we obtain from newer technological methods.
    I would say that wide distribution increases the preservation potential of a species the most because a large factor for preservation potential is the type of environment that it dies in. If the species has a widespread distribution, its remains may be found in various types of environments, so it will likely have a greater chance of decomposing somewhere that facilitates prime fossilization.
    I do believe that "Pull of the Recent" is a significant concept to consider when analyzing biodiversity and biodiversity declines. Modern day sampling methods are substantially more advanced and complete than in the past that it seems that this would have to be taken into account at least to a moderate degree. I believe that research should be done to attempt to quantify how much of the biodiversity increase can be attributed to the pull of the recent effect before determining if revisions should be made.
    There will likely be a high proportion of artifacts found rather than fossilized remains of animals. Additionally, the remains of animals will likely have characteristics suggesting human mediated death and consumption. However, due to human influence on the environment globally, a substantial amount of fossils may be very hard to come by.

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  19. 1.) I would argue it is essential to study each set of data no matter the completeness. Currently, we may be limited as far as our ability to create definite correlations between the loss of biodiversity and human impact, and arouse concern in every important figure of power. However, the data we collect now, can be used by future generations that will hopefully possess a far greater pool of material. Even without a complete fossil record, we can still produce information that has value and shows trends between fauna, biota, and humans.
    2.) Large size means more material to preserve and find. Large size is more likely to be resistant against complete dismemberment by scavengers and predators, and fair better against weathering. If the distribution of an organism is wide, there is more of a chance of an animal to be preserved without being disturbed. If an animal has small local abundance, they are more likely to be preserved because this would infer that the population isn't centered in a single area. Animals are more likely to be preserved if their abundance is dispersed rather than localized (more places for them to reach conditions that will allow for better preservation).
    3.) Larger animals require larger areas with resources. Therefore, you would expect to find small local abundances, of large body animals, because a single area can only support and provide resources for so many of them.
    4.) "Pull of the Recent" is a significant obstacle to overcome since it skews past biodiversity estimates towards modern taxa. Yet, since this issue has been discovered, there is always a possibility to fix it. I believe it is in everyone's best interest to revise modern calculation when concerns arise. Why not? Updated information makes for a more accurate record for future generation.
    5.) I believe the fossils humans from this future date will find are those creatures that are abundant today; pests and livestock. Current pollution and habitat destruction will make it very difficult for preservation of modern wild fauna. We could also speculate that they will also unearth many components of the synthetic habitats we are currently creating.

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  20. I personally believe that it is necessary and even beneficial to do studies like this one even of there is a limited fossil record, because humans have impacted the preservation of fossils, and any evidence of life that can be documented. anything that can be documents would good for the life that may or may not persist after the fall of humans. a better understanding to how and what has gone extinct, can be helpful in determining a plan to prevent an extinction event that could wipe out many of the species that are on the edge of extinction. I personally think that the only way to preserve/conserve this world is to create a way for a global interaction.

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  21. I would say it’s worth it to do this type of study to at least begin building a platform upon which we can start stacking new information. We have to start somewhere, and comparing the future to what we already have experienced and understand is a smart way to project how we may be able to respond to a future different from what we’ve seen before.

    Being large makes an individual less susceptible to predation or being dominated. Having wide, dispersed abundance would make a species more likely to survive an extinction event as certain members may be distant enough from the collapse of one ecosystem to continue living in a different one.

    I do think we need to consider that we have more information about the present than we do of the past, but I think researchers already consider this. What is happening on the planet now is reasonably predictable, despite that it has not really happened identically in the past. We can learn a great deal by comparing the present with the past, but we should also include projections of the future.

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  22. I think any information, even if it is incomplete, is helpful in discovering more about the world. Although partial information may raise more questions than it answers, it at least helps scientists realize which questions to ask and in what context. In addition, I believe that having a large size, wide distribution, and small local abundance would increase your chances of fossilization because you are more likely to find yourself in an ideal area to be fossilized. It is already challenging to become a fossil in the first place; you need an anoxic place that remains undisturbed, your remains can't be scavenged or weathered from the environment, and you need to be discovered. For this reason, many organisms have been unable to become fossils in the past. With a wide distribution, you are more likely to find yourself in this ideal set-up to become a fossil. A large size would also help (and we've learned that a large size is often tied to a wide range). Small local abundance, which at first may appear to be a disadvantage when talking about fossilization potential, also makes sense as an important determinant because, depending on the location you are referring to, fossilization may be unlikely or even impossible. Only a few specimens from a few species will ever become fossils. If there happens to be a small population occupying an area that has low fossilization potential, the size of the population itself matters less in the long run than the other factors that prevent it from becoming a fossil in the first place.

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  23. 1. Is it worth to do studies such as this one even though the fossil record is so incomplete?
    I think it is because while evidence may be scarce, conclusions can still be inferred. The collection of data is still valuable to be paired later on as methods improve.
    2. Why would large size, wide distribution, and small local abundance increase the preservation potential of an animal? Which of the three factors discussed (large size, wide distribution, small local abundance) do you believe increases preservation potential of a species the most?
    This are good for increasing the chances of an animals survival because they lessen the effects of extinction events. Large distribution minimizes the effects of species as they can move or some populations are protected.

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