Macroevolution Essay Example | Topics and Well Written Essays - 750 words

Macroevolution - Essay Example It focuses mainly on the changes which occur above the levels of species (Levinton, 67). In contrast with the micro evolution, it refers to the evolution changes within a species population. The process of specification fall within the purview depending on the forces thought to drive it. Comparative genomics, developmental and paleontology, contribute most of the evidence for patterns and the process which can be classified as macroevolution. Annelida is commonly known as segmented worms which are found in the deepest marine sediments and the city park yards. During the 20th century, Annelida was divided into three main subgroups oligochaeta, polychaeta and Hirudinea (Levinton, 88). Leeches and earthworms are similar to annelids for most people. The polychaeta comprise extent of the divergence of the Annelida and is found near the marine habitat. There are even pelagic polychaeta, which swims, preying on the other plankton and few groups exist in fresh water and the moist environment s. Around nine thousand species of polychaeta are recognized, and the overall systematics groups remain unstable. The oligochaeta and Hirudinea comprise of several other species form a clade which can be referred either clitellata or oligochaeta. It is possible the group may well belong to polychaeta; this makes polychaeta similar with Annelida. There is evidence supporting that all annelids have recently been groped as a single group. The common system used to divide polychaeta was Errantia; his was essentially a system to convenience with no aim of characterize evolutionary relationships. Recent analyses of the Annelida and other groups have resulted into new classification of polychaeta. The group split into two groups palpate and Scolecida. Scolecida contains species less than 1000; these worms are all couch form to another. Palpate have the majority of polychaeta and is also divided into aciculate and canalipalpata. Aciculate are approximately half the polychaeta species and la rgely aggress the old taxonomic group Para podia. Arthropods have taken over almost all the environment on the surface of the earth. Pieces supporting the evidence run that more species of the arthropods are multi celled animals, but that is only true for the expound species and more hobbyists are added to that list for insects. The phylum arthropod is divided in two subphyla, which are named according to their mouthparts but have several differences. The chelicerae’s, named for mouthparts derived from the appearance of the legs and the chelicerae, they do not have antennae found in the subphylum. The chelicerates have six pairs of appendages. One pair of chelicerae is followed by a pair of pedipalps, legs which are adapted with other purposes rather than walking. The horse crab is an old group which has five pairs of legs and no pedipalps; it resembles a shield with two eyes and a tail. They live in sandy zones; have been existing for a long time looking much similar as they are today. The evolutionary theory, they suggest that creatures are suited to an environment which has remained stable for a long time which would change. When exposed to direct radiation chemicals, which mutate animals DNA, changed molecules. The process of mesmerisation is known in drosophila. The metameric pattern can be extended to arthropods and other related animals. The known diversity of metameric process should evolutionary interprets the relationship between their developmental and morphological features. We view the aspects of drosophila development which involve Para segmentation and compartmentalization patterns. The regularities are compared with what is known as phenomena in other crustaceans, onyochophorans and millipedes. The Annelida segments and hypothetical soft bodied which cannot be