The growth or shrinkage of populations has nothing to do with natural selection, but with the availability of resources, and the ability of organisms to utilize those resources. This is also known as 'carrying capacity'. The natural tendency is for organisms to produce more offspring than the environment can support. So if the environment supports more individuals, then the population will automatically grow. If conditions change and the environment supports less individuals, then some individuals will starve or be otherwise unable to reproduce. Natural selection, in this case, "determines" which individuals pass, and which do not.
Responsible for publishing work in the 18th + 19th century which provided both inspiration and support for natural selection. Malthus published "An Essay on the Principles of Population" in 1798. Although not concerned with natural selection or evolutionary processes, Malthus put forward the argument that populations in nature will grow exponentially while resources (food) remain relatively stable. His suggestion then, is that population growth is limited by the amoount of resources available. This essay inspired both Darwin and his contemporary, Wallace. Lyell, a respected geologist, published a book "Principles of Geology". In this work, Lyell refined and demonstrated the argument for uniformitarianism; the idea that the earth's features are a result of long term processes that continue today as they did in the past. This idea of gradual change reinforced Darwin's ideas and observations of natural selection in animal populations, while more importantly Lyell's observations vastly changed concepts of how old the earth was. With these new estimates, the time frame for natural selection was established, and Darwin's theories of gradual change over long periods of time were realised. a valid scientific theory. Evolution is a theory, not fact!
They both decrease genetic variation .
We explore, and grow things in the world.
Prosperty seems to be the one factor that slows a population's growth. It is a natural paradox. Every other species on earth grows it population when there is plenty of food, but humans populations grow fastest in poverty stricken agricultural societies and slowest in wealthy industrial societies. France has the lowest birth rate in the world, and even the United States has had a negative growth rate for many years. Both countries rely on immigration to swell the ranks for their work force.
Exposure of a population to a toxin that kills a high percentage of the population selectively eliminates those individuals most susceptible to the toxin. This leaves the most resistant individuals to reproduce individuals that are also resistant. After many generations of this selection the whole population is resistant.
natural selection
His treatise on human populations growth posited that populations would grow at an exponential rate while food production would grow arithmetically. Darwin used this idea in his theory of natural selection and by observing that many more organisms are born than can possible survive with the resources the environment supplies proposed that there would be a struggle for existence that would favor the better adapted variant organisms.
Selective breeding
toilet paper...... just kidding it helps the plants grow and people live
Nature plays no direct role in artificial selection. That is the difference between artificial selection and natural selection. Nature does play some indirect roles in artificial selection. One indirect role is in providing the organisms with which one beings the artificial selection. Another is in influencing the choices of the organism performing the artificial selection.
There are no natural predators to keep them in check in new environments.
to grow
Since natural selection also means the survival of the fittest, those organisms that produce antibiotics (against life) had a weapon to keep other organisms from taking their space that they needed to grow and reproduce.
All organisms are variations and some of these variations confer survivability and reproductive success on the organism that processes the variant traits and the progeny of this organism and all against the immediate environment. Natural selection is just the immediate environment that selects these favored organisms over their conspecifics and then the progeny of these favored organisms leave greater allele frequencies of these favored traits in the populations gene pool and these trait grow to majority ststus as the adaption now seen in the population.
The largest effect of a reduction in bird populations is the increase in insect populations. Insect populations grow if there are fewer birds around to eat them.
Adaptation is the process by which populations grow.
B/c there's no natural competition for them to keep their numbers in check.