The theory of evolution, as set forth by Charles Darwin in 1859, stated that all plant and animal life evolved over long period
The theory of evolution, as set forth by Charles Darwin in 1859, stated that all plant and animal life evolved over long periods of time from simple to more complicated forms through mutation and adaption. He also taught that only the fittest on each species would survive. This concept is called "Evolution by Natural Selection". Natural selection is that the strongest survive and propagate and therefore increase in the strength of the species.
On the Galapagos Islands, the various species established themselves and determined territories. Evolution then set in and many unique species, such as Darwin's finches, resulted. These finches probably descended from one type of ancestor and then, due to isolation and through chance, different climates and natural forces such as food availability and type, they evolved into thirteen different types of finches. So in short, based on the food availability and types, certain fiches survived. The process of their evolution would probably have began with immigrates from the mainland. As they dispersed to different islands, new populations would be formed. Every time these satellite populations dispersed, there would be greater differences between the individual species.
Natural selection works as follows:
1. Variations exist in any population.
2. In and generation there are individuals that do not reach maturity and reproduce. Their characteristics are removed (passed on)
3. The organisms that survive to reproduce are best adapted to that environment as they have the variations that allowed them to survive (Survival of the fittest)
4. These favourable variations are passed onto the next generation, which become more and more common.
Some evidences of evolution include:
The Age of the Earth
Evolution can only take place over enormous periods of time. The fact the Earth has been dated 4,500 million years old which allows evolution to be possible.
Continents that have been separated for millions of years (due to continental drift) have evolved different creatures that use similar ecological niche.
Similarities of body structure suggest evolutionary connections. A good example of this is how the limbs of vertebrates all seem to have a 5 digit Structure that has been modified from a common ancestor to suit different environments. This is called "Pentadactyl Limb"
Living things all have the same basic chemistry suggesting a common ancestry:- All made of basically C,H,O
All have DNA and/or RNA for genetic codes
All have similar Cell membrane structure
All release energy by chemical respiration (except chemosynthetic bacteria)
Jean- Baptiste Lamark lived from 1744 until 1829 and was a scientist from France. His ideas were the start of...