Henrik Jeldtoft Jensen of the Imperial College London in 2002. The purpose of the model is to create a simple and logical ecological model based on observation. The model is designed such that ecological effects can be accounted for when determining form, and fitness of a population. Ecological genetics Ecological genetics tie into evolutionary ecology through the study of how traits evolve in natural populations. Ecologists are concerned with how the environment and timeframe leads to genes becoming dominant. Organisms must continually adapt in order to survive in natural habitats. Genes define which organisms survive and which will die out. When organisms develop different genetic variations, even though they stem from the same species, it is known as polymorphism. Organisms that pass on beneficial genes continue to evolve their species to have an advantage inside of their niche. Evolutionary ecologists Charles Darwin The basis of the central principles of evolutionary ecology can be attributed to Charles Darwin (1809–1882), specifically in referencing his theory of natural selection and population dynamics, which discusses how populations of a species change over time. According to Ernst Mayr, professor of Zoology at Harvard University, Darwin’s most distinct contributions to evolutionary biology and ecology are as follows: “The first is the non-constancy of species, or the modern conception of evolution itself. The second is the notion of branching evolution, implying the common descent of all species of living things on earth from a single unique origin.” Additionally, “Darwin further noted that evolution must be gradual, with no major breaks or discontinuities. Finally, he reasoned that the mechanism of evolution was natural selection.” George Evelyn Hutchinson George Evelyn Hutchinson’s (1903–1991) contributions to the field of ecology spanned over 60 years, in which he had significant influence in systems ecology, radiation ecology, limnology, and entomology. Described as the “father of modern ecology” by Stephen Jay Gould, Hutchinson was one of the first scientists to link the subjects of ecology and mathematics. According to Hutchinson, he constructed “mathematical models of populations, the changing proportions of individuals of various ages, birthrate, the ecological niche, and population interaction in this technical introduction to population ecology.” He also had a vast interest in limnology, due to his belief that lakes could be studied as a microcosm that provides insight into system behavior. Hutchinson is also known for his work Circular Casual Systems in Ecology, in which he states that “groups of organisms