Is macroevolution simply microevolution over very long perio

Is macroevolution simply “microevolution over very long periods of time?” What processes or events become very important at the macroevolutionary scale, where the fossil record gives evidence of different species, genera, families, and higher taxa replacing others?

Solution

It is not macroevolution simply “microevolution over very long periods of time but microevolution is leading to macroevolution and speciation over very long periods of time.

\"Gradualism and the primacy of natural selection followed by Speciation and genome reorganization due to genetic drift\" are the processes or events that become very important at the macroevolutionary scale, where the fossil record gives evidence of different species, genera, families, and higher taxa replacing others. For example, micro-evolutionary changes that accumulate within two organisms of opposite sex may cause macro-evolutionary changes in the offspring produced by their mating. The offspring greatly varies genetically from their parents and is special enough to result in speciation; this is called “macroevolution.”

In Darwin\'s theory, the microevolutionary changes observed in the phenotypic features of the “finches”, beaks, tortoises and coral reefs that are observable during a scientist’s lifetime provide support for Darwin’s view that all life is connected in a branching pattern of phylogenetic tree. According to Darwin, natural selection including genetic variations is leading to “branching pattern” in the origin of species. He concluded in his lifetime microevolutionay observation base on gradualism of species evolution with “branching interrelationships” among all living beings by meticulous “metaphor of branching pattern” as described below.

Darwin’s theory of gradualism and evolution:

Darwin uses Gradualsim and he proposed that the gradual changes associated with variations of a species through evolution to get adapted to the present ecosystem with no much transitional forms. Human evolution based on the gradualism and their adaptations are extremely complex. Initially in the gradualism, natural selection operates to obtain specific traits according to biome, ecosystem because of large-scale events followed by formation of rivers, water availability and habitat formation. Humans did not evolve from primates until just 7 million years ago; while life appeared on earth 3.5 billion years ago. Humans are well adapted for the environment and developed their adaptation features as per interspecific and intraspecific genetic variations. If the evolution time-line compressed to a calendar year, the first organism would appear around March and Humans would not appear until December 31.

Darwin has developed a meticulous scientific theory about the exact biological evolution of a species and he explained the evolution of modern species over a long period from a common ancestor base on morphological convergent & divergent features as explained below.

Descent with modification from a common ancestor mean that species living at any given time such as present and pre-existing species are derived from a common ancestor and their characteristic traits reflect that ancestry as well as changes over time. New species are descended from pre-existing species finally they are able change their traits over time as an evolutionary adaption through environmental variations.