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19

The conservation biology literature has a great deal of information, particularly with reference to developing species survival plans (e.g., Traill et al. [2007] report a minimum effective population size of ~4,000 will give a 99% persistence probability of 40 generations). Because the question specifically mentions human populations, I'll focus my answer ...


15

A hormone is defined as "a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism" (I'm just taking Wikipedia definition). Hormones work by binding to specific receptors present on their target cells so, if there is something in the environment that mimics the hormone, by ...


13

While poison affects not every organism equally, plants did develop some poisons to avoid being eaten. However, if you look at the great multitude of so-called secondary metabolites, most of them are poisonous to either viruses, bacteria, fungi or other microorganisms, or insects, or even other plants. Plant evolution just hasn't had time to adapt to humans. ...


13

There are several key ways in which rising atmospheric CO2 concentrations will affect photosynthesis, and these are related to the different types of photosynthesis. In order to properly answer your question, I'll provide some background about photosynthesis itself. Photosynthesis evolved in a high-CO2 atmosphere, before the oxygen-enrichment of the ...


12

I did some research on the topic and came accross this paper by Johnson et al. I am not a zoologist, so everything I write here is taken from the references paper. The authors used genetics to estimate gene flow between different populations of limpets Lepetodrilus fucensis which is considered to be an endemic hydrothermal vent animal. They used a ...


11

I wanted to add a little more to the excellent answer above, especially since the OP asks about research into this question in a "real-world context". There is a substantial body of evidence on exactly this question that comes from experiments at "Free Air CO2 Enrichment" (FACE) sites. FACE is an experimental method/technology in which standing ecosystems ...


10

Following up on Alexander's response, I read a little more on the subject by looking at some of the references in the Johnson et al. paper. This paper discusses an interesting case where researchers could study a hydrothermal vent ecology before and after a catastrophic eruption giving a "natural clearance" experiment. Since endemic organisms were ...


10

Population dynamics occupies a whole subset of mathematical biology. Perhaps the most pragmatic uses for modelling population dynamics come from the fields of epidemiology for modelling disease infection and transmission through a population (one such article), or ecology modelling things like forestation, fishing dynamics, predator-prey relationships (an ...


9

Basically, they don't. Ecosystems are pretty much either de facto, delimited by geographical boundaries, or defined by us. For example, an underground lake would be an ecosystem and it is organized in such a way for the simple reason that there is no communication between it and any other system. Most ecosystems however, do communicate. For example, we ...


8

Leonardo's already given you an excellent answer, but I thought I'd add my perspective. I'm a mathematical epidemiologist, so I'd at least like to believe these types of models are useful. For me, there are a number of things population dynamics models are especially useful for: Highlighting data requirements. Yes, models need data, as you've mentioned. ...


8

You can access the Imperial College global population dynamics database. They will have time series data at specific locations. http://www3.imperial.ac.uk/cpb/databases/gpdd There is a sister database as well that might be useful. http://lits.bio.ic.ac.uk:8080/litsproject/ These contain several hundred time series, and you can see a paper that used them ...


7

Two previous answers listed many applications of population dynamics models. I want to add that they are also important for conservation of endangered species. For example classical stage-class model (Crouse et al 1987, free copy) indicate that the most effective way to protect sea turtles is reducing mortality of large juveniles. Moreover, you don't have ...


7

I think it does make sense - with a population density for finland that is so low, the disease with such a low beta cannot communicate to enough people to propagate. The number of people who have this disease will be fewer each week. I think this makes sense because at 16 / km^2, you can expect that practically nobody will ever see each other. This is ...


7

No, I don't think there is any kind of auto-regulation. You'll be interested in various model of prey-predator or of consumer-ressource interactions. For example the Lotka-Volterra equations describe the population dynamics of two co-existing species where one is the prey and the other is a predator. Let's first define some variables… $x$ : Number of ...


6

There does not appear to be a current standard, but Veg-X is a standard that has been developed to facilitate exchange of plot-based vegetation data, and may provide the closest to what you are looking for. Veg-X is described in Wiser et al 2011 and the project home page is http://wiki.tdwg.org/Vegetation/ From the abstract: The exchange standard for ...


6

That will depend on many things. How do you define surface? Is one meter underground still "surface"? How about a kilometer? Also, how large an area are we talking about? You could probably find a square millimeter in, for example, Antarctica that has no organisms. I don't think you would find a square kilometer with no organisms though. There are ...


6

I don't think one can fully answer to such a broad question. It depends on the population, the environment (presence of predators for example), the genetic background (having a big stomach is good but only if the intestin is big too), the population's social relations, .. Many traits are correlated and one might want to say that a given trait is beneficial ...


5

I guess you meant the population size stability. It is considered that the biosystems will increase their capacity of adaptation when evolving in very fluctuating environments. I believe the population stability is embedded in the adaptability of individuals. There is a measurement about it, evolvability, when the environment changes, the faster the ...


5

I'm not an expert on Shannon-Weaver Index, but according to wikipedia it is the same as exponentially transformed Renyi entropy. If it is the case, you can compare them since they are scale invariant summary statistics. If you want error bars, you can always try resampling methods such as bootstrapping. Hypothesis testing can also be done with bootstrapping, ...


5

There are many websites which describe this phenomenon. They all seem to confirm the basic premise of the question: in tropical rain forests most of the minerals are held in the biomass and rapid decomposition contributes to the recycling of these nutrients for new growth. One example is here. Tropical rainforests are noted for the rapid nutrient cycling ...


5

Barring the very obvious surfaces (the pits of active volcanoes), the only place I'm aware of that might not contain life is the Atacama Desert near the Andes Mountains in Chile and Brazil. Whereas other places that seem inhospitable - Antarctic, Hot Springs, regular deserts, extremely high altitudes, etc. - the basic necessities for life still exist ...


5

if the pool were just sitting out in open air, on earth and all that good stuff, it certainly would, given enough time. This thought experiment is in the same vein that inspired Darwin when he reflected on his experiences on his visit to the Galapagos islands. Think about it - the many islands which are formed by upheaval were lifeless when they first ...


5

Although work in those areas is definitely all related, there are some kind of general differences in how those labels tend to be used, and I'll take a stab at defining them: Mathematical ecology - this is typically the creation of theoretical models composed purely from math (i.e. not stochastic computer models). Examples include a lot of classics from ...


5

The cost would increase; either because pollination services are not provided and the supply is decreased; or because the cost to producers goes up as they must pay for artificial pollination. See the extremely detailed analysis in Winfree et al. edit I imagine what you're actually asking for is a $ figure "per apple". This depends on the location, crop, ...


5

A parasitic interaction is when one species has a fitness increase from this interaction (benefit) while the other has a fitness decrease (cost). Note: you don't need to have physical contact to have an interaction. As soon as the presence of one specie influence the fitness of the other, it is enough to consider that there is an interaction. In the case of ...


4

It sounds like you are interested in beta diversity which is the change in taxa composition (i.e., alpha diversity) between plots. There are a number of approaches to calculating beta diversity and the correct choice generally depends on the question(s) you are trying to answer. The most common approaches are very well described in this paper: Anderson, ...


4

After talking to my teacher, he said that biological control is the introduction of species to control another species, however species may be introduced for other reasons (the "Introduced Species" method), such as to "assist an ecosystem cope, flourish or re-establish itself." The example he gave was the introduction of South African veldt grass to ...


4

In an environment where all plants are resistant to certain parasites, a rare breed which has a mechanism against this resistance has free play - lots of food and no competition. However, in plants which do not have the resistance, this rare parasite breed may be at a disadvantage compared to parasites who do not have the mechanism against that resistance ...


4

For climate related data you can start from Realclimate pages on data repository. For ecological data I always found less global data, but a good starting point may be the Ecological Society of America Data Registry page. An overview of repositories can be found the the Simmons University Open Access Directory.



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