When Charles Darwin published his radical theory of evolution by natural selection in 1859 it was attacked by many early biologi
sts as seriously flawed. Today his ideas are accepted as correct by biologists. From what we know of how science works, and the scientific method, why might opposition to Darwin's ideas disappear over the last 160 years?
The scientific process involves the formulation of hypotheses that enable to answer questions about the real world, and then to carry out experiments or observations that are used to confirm (or reject) such predictions. In the last 160 years, Darwin's ideas on 'descent with modification' have constantly been subjected to experimental assessment, and obtained data confirmed his observations. For example, molecular evidence based on the DNA and RNA -which constitute the genetic material of all living organisms- has shown the conservation of this process. In consequence, molecular evidence has been used to construct 'evolutionary' phylogenetic trees from DNA/RNA sequences. Moreover, evidence in genetics has shown the critical role played by mutations in the mechanism of natural selection proposed by Darwin, thus also confirming his theories. These are only some examples, and supporting evidence confirming Darwin's ideas has been collected from different research fields ranging from ecology to molecular biology.
The horse will give 32 chromosomes and donkey will give 31 chromosomes to the offspring. The offspring has 63 in total. It is odd so it can not produce normal germ cell. So it is sterile.
When plants do not get enough nitrogen, they are unable to produce amino acids (substances that contain nitrogen and hydrogen and make up many of living cells, muscles and tissue). Without amino acids, plants cannot make the special proteins that the plant cells need to grow.
