Evolution by natural selection was proposed as a theory by Darwin and Wallace. What evidence is there in the world today to suggest that species evolve by this mechanism?
Alfred Russel Wallace was a naturalist who independently proposed the theory of evolution by natural selection. A great admirer of Charles Darwin, Wallace produced scientific journals with Darwin in 1858, which prompted Darwin to publish On the Origin of Species the following year.
Wallace worked around the world gathering evidence to support his evolutionary theory. He is best known for studying warning colouration in animals, one example being the golden birdwing butterfly (Ornithoptera croesus), as well as his theory of speciation.
After a variety of zoological discoveries, Wallace proposed a theory of evolution which matched the unpublished ideas Darwin had kept secret for nearly 20 years. This encouraged Darwin to collect his scientific ideas and collaborate with Wallace. They published their scientific ideas jointly in 1858.
The idea behind the theory of evolution through the process of natural selection is that all species of living things have evolved from simple life forms over a period of time. The Earth is about 4.5 billion years old, and there is scientific evidence to suggest that life on Earth began more than 3 billion years ago.
The accepted theory of evolution explains that it happens by natural selection. The key points are given below.
This model can be used to demonstrate how natural selection can occur based on the characteristic of camouflage in a population of prey organisms.
This model shows that even though both species of prey are predated, the species with the highest degree of camouflage can survive. In reality, these organisms would be able to breed and pass on their camouflage genes. Where there was once an even distribution of green and white organisms, now the camouflaged organisms outnumber the non-camouflaged organisms by 10 to 1.
In this model the prey do not move. What if the white organisms were much faster than the green ones?
There may also be bias in the case of the predator. The scientist selecting the prey may do so not on the basis that some are easier to see, but on the basis that they were aware of what the results should be.