In 1858, Charles Darwin and Alfred Wallace released a joint scientific paper which introduced the concept of evolution by means of natural selection. This paper, along with Darwin’s subsequent publication, “The Origin of Species,” changed the way science and society explained events in our natural world.
Many scientist before them had observed the fact that organisms change, or evolve over time. Darwin and Wallace rocked the world by describing the specific mechanism by which new forms could arise -- natural selection.
Difference between Evolution and Natural Selection
Evolution
In biology, evolution can be defined simply as inheritable change in a population that ultimately results from the interaction of individuals with their environment.
Its action over vary large stretches of time explains the origin of new species, occasionally the elimination of existing species and ultimately the vast diversity of the biological world.
Contemporary species are related to each other through common decent (ancestors that they share), and are products of evolution over billions of years.
Key concepts of evolution:
Any change must be inheritable (able to be passed on to the next generation).
These changes are regulated by natural selection.
Natural Selection
This is the process in nature by which only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics to the next generation, while those less well adapted tend to be eliminated, where environment means the combined biological and physical influences.
biological influences: include things like disease, competition, and predation
physical influences: include things like drought, fire, flood
Natural Selection is the process. Evolution is the outcome.
Essential components of Evolution via Natural Selection
Genetic Diversity - Populations of individuals are genetically diverse. Even members of the same species have characteristics that very from one individual to the next.
Fitness - In any given environment, some individuals have characteristics that put them at an advantage over individuals who do not possess those characteristics.
Population Shift - In any given environment, those individuals who have advantageous characteristics will generally be healthier, live longer, and leave more offspring than individuals who do not possess those characteristics. The population will, over time, contain more and more individuals with the advantageous characteristic, and fewer individuals who do not possess the characteristic.
The Power of Natural Selection over Time
Two organisms are of the same species if they can produce fertile offspring with each other. Over time, natural selection can make sub-populations within a species genetically different enough so that they are no longer able to reproduce with each other, creating separate species (reproductive isolation). Natural selection does not always result in new forms or species. Natural selection may also result in the elimination of species from the environment (extinction).
In a nutshell; the “goal” of all organisms is to live long enough to produce reproductive offspring. Individuals that can locate, harvest and utilize the resources from their environment the most efficiently, while minimizing the influence of limiting factors acting upon them, will be the most successful in continuing their genes to the next generation.
About the Image
Photo of the Berlin Archaeopteryx taken by Raimond Spekking and found on Wikipedia.
