Mendel's experiments on pea plants (Pisum sativum) over many generations
His observation on seven traits include
1.Color of flower is purple or white
2.Flower position is axil or terminal
3.Stem length is long or short
4.Seed shape is round or wrinkled
5.Seed color is yellow or green
6.Pod shape is inflated or constricted
7.Pod color is yellow or green
Modern Evolutionary Synthesis
Evolution is the change over time of inherited traits found in a population of individuals. Inherited traits are distinguishing characteristics comprising a phenotype encompassing such observables as physiology, anatomy, biochemistry and behavior that are passed on from one generation to the next.
Charles Darwin’s work on "Origin of Species" led to overwhelming acceptance of theory
of evolution by natural selection within the scientific community. In the 1930s,
Darwinian natural selection was combined with Gregor Mendelian’s theory of genetics
as the basis for biological inheritance and mathematical population genetics to
form the modern evolutionary synthesis, in which the connection between the units
of evolution (genes) and the mechanism of evolution (natural selection) was made.
This powerful explanatory and predictive theory has become the central organizing
principle of modern biology, providing a unifying explanation for the diversity
of life on Earth. In the 1940’s, the identification of DNA as the genetic material
by Oswald Avery and colleagues and the subsequent publication of the structure of
DNA by James Watson and Francis Crick in 1953, demonstrated the physical basis for
inheritance. Since then, genetics and molecular biology have become core parts of
The modern theory of evolution is based on two primary key points:
All living beings are related to each other to varying degrees through common decent, developed from a single common ancestor.
The origin of a new species results from random heritable genetic mutations or changes, some of which are more likely to spread and persist in a gene pool rather than others.