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Three goals of plant taxonomy are the identification, classification and description of plants. The distinction between these three goals is important and often overlooked. Plant identification is a determination of the identity of an unknown plant by comparison with previously collected specimens or with the aid of books or identification ...
Plant evolution is the subset of evolutionary phenomena that concern plants. Evolutionary phenomena are characteristics of populations that are described by averages, medians, distributions, and other statistical methods. This distinguishes plant evolution from plant development, a branch of developmental biology which concerns the changes that ...
if the allele A frequency is denoted by the symbol p and the allele a frequency denoted by q, then p+q=1. For example, if p =0.7, then q must be 0.3. In other words, if the allele frequency of A equals 70%, the remaining 30% of the alleles must be a , because together they equal 100%.
The idea of a tree of life arose from ancient notions of a ladder-like progression from lower into higher forms of life (such as in the Great Chain of Being).Early representations of "branching" phylogenetic trees include a "paleontological chart" showing the geological relationships among plants and animals in the book Elementary Geology, by Edward Hitchcock (first edition: 1840).
Evolutionary taxonomy arose as a result of the influence of the theory of evolution on Linnaean taxonomy. The idea of translating Linnaean taxonomy into a sort of dendrogram of the Animal and Plant kingdoms was formulated toward the end of the 18th century, well before Charles Darwin's book On the Origin of Species was published. [4]
It is important to note the impact that humans have on genetic diversity as well, and be aware of the ways to reduce harmful impacts on natural environments. [26] Major roads, waterway pollution, and urbanization all cause environmental selection and could potentially result in changes in allele frequencies. [ 27 ]
Land plants evolved from a group of freshwater green algae, perhaps as early as 850 mya, [3] but algae-like plants might have evolved as early as 1 billion years ago. [2] The closest living relatives of land plants are the charophytes, specifically Charales; if modern Charales are similar to the distant ancestors they share with land plants, this means that the land plants evolved from a ...
In negative frequency-dependent selection, the fitness of a phenotype or genotype decreases as it becomes more common. This is an example of balancing selection. More generally, frequency-dependent selection includes when biological interactions make an individual's fitness depend on the frequencies of other phenotypes or genotypes in the ...