What Natural selection proposes
Natural selection proposes that certain heritable biological traits that are beneficial to an individual's survival are more likely to be passed on and lead to evolution.
Natural selection is a gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited is beneficial or harmful for their adaption to their environment. It is a key mechanism of evolution.
Variation exists within all population of organisms. This occurs because random mutations arise in the genome of an organism and these mutation are passed to their offspring. Throughtout the individuals lives, their genomes interact with their environments to cause variations in traits. Individuals with cartain variants of the trait may have a greater chance at survival and reproduce more than individuals with other, less successful variants. Therefore the population because more adaptable and evolves.
Natural selection is a gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited is beneficial or harmful for their adaption to their environment. It is a key mechanism of evolution.
Variation exists within all population of organisms. This occurs because random mutations arise in the genome of an organism and these mutation are passed to their offspring. Throughtout the individuals lives, their genomes interact with their environments to cause variations in traits. Individuals with cartain variants of the trait may have a greater chance at survival and reproduce more than individuals with other, less successful variants. Therefore the population because more adaptable and evolves.
This diagram above shows how certain beaks are passed on by what type of food that they eat. An example is, beaks used for grubs will mostly not be inherited if the bird's main source of food are seeds
Steps in natural selection
There are 4 key steps in natural selection.
1. Variation in trait - The population will have different characteristic which will help it survive.
2. Reproduction and competition - The organisms will compete with each other to survive and reproduce so that they can pass down their trait to the offspring.
3. Heredity - what certain traits are passed down. The trait that benefits the organism's survival will be the most likely passed down.
4. result - What certain traits are selected that will help the organism's in its survival
1. Variation in trait - The population will have different characteristic which will help it survive.
2. Reproduction and competition - The organisms will compete with each other to survive and reproduce so that they can pass down their trait to the offspring.
3. Heredity - what certain traits are passed down. The trait that benefits the organism's survival will be the most likely passed down.
4. result - What certain traits are selected that will help the organism's in its survival
Steps in Natural selection example
In these steps i will use elephants as an example. These steps are:
1. Variation in Traits - There are lots of different variety of elephants that will help its survival, for example some with long trunk some with short trunks.
2. Reproduction/competition - The 2 elephants will compete to survive and reproduce. The short trunk elephants are not able to reached their food source while the long trunk elephants can. Due to their short trunks, they will survive less. Due to this they do not get to reproduce to their full potential and produce less than long trunk elephants
3. Heredity - The surviving long trunk elephants have more long trunk babies because the trait has a genetic basis
4. Result - The more advantageous long trunk elephant, allows the elephant to have more offspring which becomes more in population. If this process continues, all individual will have long trunks and the short trunk elephants will be no more are extremely rare.
1. Variation in Traits - There are lots of different variety of elephants that will help its survival, for example some with long trunk some with short trunks.
2. Reproduction/competition - The 2 elephants will compete to survive and reproduce. The short trunk elephants are not able to reached their food source while the long trunk elephants can. Due to their short trunks, they will survive less. Due to this they do not get to reproduce to their full potential and produce less than long trunk elephants
3. Heredity - The surviving long trunk elephants have more long trunk babies because the trait has a genetic basis
4. Result - The more advantageous long trunk elephant, allows the elephant to have more offspring which becomes more in population. If this process continues, all individual will have long trunks and the short trunk elephants will be no more are extremely rare.
Selection pressure
Selection pressures are environmental factors which may reduce reproductive success in a population and thus contribute to evolutionary change or extinction through the process of natural selection. It is a force that causes particular organism to evolve in a certain direction for it to help it adapt with there environment
Some examples of where selective pressures come from include:
- Competition
- Predation
- Dissease
- Parasitism
- Land clearance
- Climate changes
- Pollutants
Some examples of where selective pressures come from include:
- Competition
- Predation
- Dissease
- Parasitism
- Land clearance
- Climate changes
- Pollutants
Survival of the fittest
"Survival of the fittest" is a phrase meaning an individual who are more adapted in their current environment will live and last longer than those who struggle in their environment.
How survival of the fittest is different to Natural selection
Survival of the fittest is different to natural selection. Natural selection is a mechanism of evolution. It is not survival. Natural selection is a process that generates or shape adaptation over a long period of time. For a trait to be shaped by natural selection it must be genetic and inheritable. while Survival of the fittest is a phrase individual who are more adapted in their current environment that other.