Interactions and relationships among organisms and their environment. This includes biotic and abiotic (non-living/environmental) factors that impact organisms.

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9
votes
4answers
662 views

What prevents predator overpopulation?

I've often heard that a population, human or otherwise, will continue to grow as long as there is food available (assuming nothing else is killing them off). It makes sense: if you have food you can ...
4
votes
1answer
249 views

Body size, what are the evolutionary trade-offs?

Background Considering just the "Kingdom Animalia" branch of organisms. It is clear that bigger does not necessarily mean better - there is large variation in body size... From the 94 µm long ...
12
votes
3answers
275 views

When are population dynamics models useful?

When are population dynamics models useful? There seems to have been a lot of research about it, but how does it help? If I need data about how a population will evolve under what conditions, I need ...
4
votes
3answers
153 views

Why are the fertility rates of large predators kept low?

Predators at the top of a food chain, like lions, seem to have a relatively low fertility rate, which fits well to the ecosystem and avoids overpredation. But what is the mechanism that keeps the ...
24
votes
2answers
578 views

Smallest viable reproducing population

What is the smallest viable reproducing population, such as in a human population. By viable I mean a population which keeps genetic defects low (enough). A very strongly related question: what is ...
6
votes
1answer
123 views

Effects of selection on effective population size

Background The effective population size ($N_e$) is a central concept of evolutionary biology and is influenced by several parameters. For example: sex ratio bias affects $N_e$ $\left(N_e = ...
13
votes
2answers
5k views

How will rising carbon dioxide levels in the troposphere affect photosynthetic producers?

Much discussion has been had about the affects of climate change on plantlife, but how will rising carbon dioxide concentrations affect the photosynthetic process itself? Since CO₂ is a reagent in ...
6
votes
2answers
82 views

What is the mechanism behind plants losing their leaves? [duplicate]

Do plants that lose their leaves (i.e., deciduous plants) do so because of external conditions (e.g., drought, cold), or because of an internal process? Another way of looking at it: if you take a ...
3
votes
1answer
54 views

Confusion regarding niches in evolution theory

This is the definition of a niche from Crash Course: An area of the environment that requires a special set of skills or traits to extract food and reproduce. Obviously, this version of the ...
3
votes
1answer
255 views

Parasitism and mimicry

I was reading this article which states this: Classical Batesian mimicry, in which an undefended mimic evolves to look like a toxic model, is a parasitic relationship in which the mimic gains ...
1
vote
0answers
21 views

Classification of degree of infested areas by pine processionary moth on regions

I'm making a thesis about pine processionary moth distribution on the regions of algeria! i'm making tests about if there are spatial autocorrelation of this insects on the regions. and i'm doing ...