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Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charles Darwin popularised the term "natural selection", contrasting it with artificial selection, which is ...
Oct 19, 2023 · Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others. Individuals with adaptive traits — traits ...
selection, in biology, the preferential survival and reproduction or preferential elimination of individuals with certain genotypes (genetic compositions), by means of natural or artificial controlling factors. The theory of evolution by natural selection was proposed by Charles Darwin and Alfred Russel Wallace in 1858.
- The Editors of Encyclopaedia Britannica
Evo 101. Natural Selection. Natural selection is one of the basic mechanisms of evolution, along with mutation, migration, and genetic drift. Darwin’s grand idea of evolution by natural selection is relatively simple but often misunderstood. To see how it works, imagine a population of beetles: There is variation in traits.
- Natural Selection Explained
- Natural Selection Examples
- Principles of Natural Selection
- Types of Natural Selection
- History of Natural Selection
Even if a parent were perfectly adapted to the environment, the environment will change, leaving the offspring maladapted to the environment. Because there are many animals and few resources, only the best and most fit organisms can reproduce.Natural selection works against all organisms, and it can be thought of as the environment and forces actin...
Example of Stabilizing Selection
For stabilizing selection, imagine a population of mice that lives in the woods. Some of the mice are black, some are white, and some are grey. If the mice had no predators, and no other forces acting on the color of their coat, it would have no reason to change and would only change randomly in response to certain mutations in the DNA. However, that is not the case with these mice. They have lots of predators. Foxes and house cats prey on the mice during the day. In the nighttime, the owls a...
Example of Directional Selection
It is important to consider different traits in the same population of animals. Imagine again the population of mice living in the woods. Instead of their color, consider a trait that runs on a continuous scale. Imagine that the mice vary in size from a normal sized mouse to something much larger than a rat. Although the mice are the same species, they grow into many different sizes. The predators, however, have a terrible time trying to catch and eat the largest of the mice. Not only do the...
Example of Diversifying Selection
Okay, last time with the mice. But this time, consider a new trait in the population. Let’s imagine that some of the mice begin to grow skin flaps between their front and back legs. Effectively, it makes a parachute that allows them to glide away from predators. Mice that fully have the skin flaps do really well and are almost always able to escape predators. Likewise, mice without the flaps avoid the trees and open spaces that mice with flaps venture into, and are much better at hiding from...
There is an incredible variety of selective forces in the natural world, ranging from interspecies competition, to predator-prey dynamics, to sexual selection between the different genders. The defining characteristic of natural selection is that it is a force that allows some organisms to reproduce more than others. Natural selection does not alwa...
As animals diversify and fill different niches, the pressures exerted on them can change in many ways. The functional requirements to be a bird are much different than those required to be a fish. Their food is different, the medium they exist in is different, and they must obtain oxygen in a different way. Natural selection thus selects for very d...
Before Darwin
In 1809, the world of biology was very different. This was the year Charles Darwin, the originator of the theory of natural selection, was born. Darwin was born into a world were transmutation was the dominant theory of evolution.According to this theory, animals changed throughout their lifetime, and they passed these changes on to their offspring. For example, giraffes got their long necks because every generation stretched as far as possible to reach the leaves. This theory did not sit wel...
Darwin’s Theory
In this idea, evolution was driven by four principles. Between individuals, the was variance. Organisms can only get traits via inheritance. A force, natural selection, let’s the fittest animals reproduce the most. Finally, these actions all take place over time, an important aspect of evolution. Together, these principles drive changes over time. However, Darwin did not publish these ideas immediately. He spent the next 20 years gathering more evidence and solidifying his argument. This proc...
- Gabe Buckley
157. Natural selection is a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. This process causes species to change and diverge over time. Natural selection is one of the ways to account for the millions of species that have lived on Earth.
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Nov 10, 2023 · Natural selection is the adaptation strategy of living organisms on Earth. It occurs when they acquire and evolve a trait with time that provides them a distinct advantage for their survival and reproduction over other organisms in the population. Darwin called them ‘survival of the fittest.’. Organisms with better adaptive traits survive ...
