Natural selection is the process by which individuals with characteristics that are advantageous for reproduction in a specific environment leave more offspring in the next generation, thereby increasing the proportion of their genes in the population gene pool over time. Natural selection is the principal mechanism of evolutionary change, and is the most important idea in all biology. Natural selection, the unifying concept of life, was first proposed by Charles Darwin, and represents his single greatest contribution to science.
Natural selection occurs in any reproducing population faced with a changing or variable environment. The environment includes not only physical factors such as climate or terrain, but also living factors such as predators, prey, and other members of a population.
Mechanism of Natural Selection
The mechanism of natural selection depends on several phenomena:
• Heredity: Offspring inherit their traits from their parents, in the form of genes.
• Heritable individual variation: Members of a population have slight differences among them, whether in height, eyesight acuity, beak shape, rate of egg production, or other traits that may affect survival and reproduction. If a trait has a genetic basis, it can be passed on to offspring.
• Overproduction of offspring: In any given generation, populations tend to create more progeny than can survive to reproductive age.
• Competition for resources: Because of excess population, individuals must compete for food, nesting sites, mates, or other resources that affect their ability to successfully reproduce.
Given all these factors, natural selection unavoidably occurs. Those members of a population that reproduce the most will, by definition, leave more offspring for the next generation. These offspring inherit their parents' traits, and are therefore also likely to succeed in competition for resources (assuming the environment continues to pose the same challenges as those faced by parents). Over several generations, the proportion of offspring in a population that are descended from the successful ancestor

Uloborid spider eggs and spiderlings. In any given generation, populations tend to create more offspring than can survive to reproductive age.
increases, and traits that made the ancestor successful therefore also increase in frequency. Natural selection leads to adaptation, in which an organism's traits conform to the environment's conditions for existence.
Answer: Oxygen and glucose are both reactants in the process of cellular respiration
Explanation: hope this helps!
Answer:
Una variable de control (o constante científica) en la experimentación científica es un elemento experimental que es constante y sin cambios durante el curso de la investigación. ... Las variables de control en sí mismas no son de interés primario para el experimentador.
Explanation:
The answer is A. Fallopian Tube. The ovaries create the egg and the fallopian tubes hold the zygote until it is fertilized, then transfer it to the uterus.
Answer: Adaptive immunity
Explanation:
The adaptive immunity is also known as acquired immunity. It is a sub system of the overall immunity.
It can defined as the immunity which is not present in the body when we are born. It develops in the body when it is exposed to the pathogens no matter it is natural or artificial.
The acquired immunity can develop in the body and makes the body susceptible to infections and develops prevention for the next time when the body will be exposed for the next time.
