Charles Darwin's Framework Of Natural Selection

Evolutionary biology is a conceptual subfield of biology that seeks to explain the origin and diversification of life. The sub-field formally began when Charles Darwin demonstrated that all organism share a common ancestry and that the key mechanism of evolution is natural selection. While no universally accepted definition exists, ‘Darwinism’ can loosely be defined as a theory of biological evolution developed by Charles Robert Darwin and his contemporaries, thats states that all species of organisms arise and develop through the natural selection of small, inherited variations that increase an individual’s ability to compete, survive, and reproduce (The American Heritage Dictionary, 2000). Although ‘natural selection’ is typically prized

For example, evolutionists are yet to come to a consensus on the definite relationship between microevolutionary and macroevolutionary processes due to the lack of evidence for macroevolution. Microevolution, a theory supported by substantial biological evidence, essentially describes evolution resulting from a succession of relatively small genetic variations that often cause the formation of new subspecies over a reasonably small time period (The American Heritage, 2002). One only has to look as far as the evolution of resistance of pests to pesticides, weeds to herbicides and pathogens to medicines to observe microevolutionary processes in action. Other classic demonstrations include industrial melanism in peppered moths (Kettlewell, 1973; Majerus, 1998), adaptation of plants to different soil conditions (Snaydon, 1970; Antonovics, Bradshaw & Turner, 1971), divergence of mosquitofish introduced to Hawaii (Stearns, 1983), adaptation of guppies to different predation regimes in Trinidad (Endler, 1980; Reznick et al., 1997), and changes in the size and shape of finch beaks in the Galápagos Islands (Grant & Grant, 1995). Hence, with the extensive scientific backing that has been acquired over several decades, it is reasonable to adjudge microevolution as a valid

While it draws from a number of biological disciplines, evolutionary developmental biology has its own set of questions, approaches and methods - some of which look to answer the most fundamental questions about the mechanism of macroevolution. Moreover, evo-devo is essentially the fusion of ontogeny, or the changes an individual organism goes through during embryonic and juvenile growth stages, and phylogenic evolutionary change that looks to address unanswered questions about major, abrupt, evolutionary changes. Advancements in macroevolutionary aspects of evo-devo are limited however, as the coverage of ontogenetic stages is incomplete, making it difficult to empirically test each model. Additionally, investigations of ontogeny at a macroevolutionary scale are by nature more limited to descriptive patterns, rather than explanatory processes that include the relative adaptive value of traits (Streelman, 2014). Currently, the only plausible evidence for macroevolution is that used to support the theory, universal common ancestry such as ontogeny and developmental biology, anatomical vestiges and embryology. Evolutionary biologists are yet to present a clear and coherent explanation for the transition from reptiles to birds (macroevolutionary