Explain process of selection of taxonomic characters, Biology

Assignment Help:

Explain process of Selection of taxonomic characters

Selection of taxonomic characters

Eventually classification systems may be based almost entirely on direct study of the genes themselves, but for a long time we will continue to use information for many sources. Characters useful for classifying organisms must be measurable, describable, and relatively invariable, regardless of the environment in which the organism grows. For a plant whose leaves have different shapes depending upon whether they grow in water or in air, leaf shape would not be a good taxonomic  character. For groups with good fossil records, direct measures can be made of the rates at which different features have evolved. Nucleic acid analyses and amino acid sequences in proteins, especially when combined with fossil evidence (of the splitting of groups) provide very accurate estimates of the average rate of change in genes and their direct consequences. Although the same procedures are used with all organisms, the characters upon which classification is based differ and only those characters which vary strikingly among organisms are measured. Flowering plants offer branching patterns, leaf shapes, specialised cells, reproductive structures and so on.

Many invertebrates have shells that are readily preserved as fossils and can be measured long after the animal has died. Thus taxonomic character is a feature which is present id all appropriate specimens at appropriate times. One should be very cautious in selecting useful characters. The choice of character is directly based on the accumulated experience of the taxonomist. One should select only those characters which are stable within species or groups, easily studied and quite distinctive in its easy separation from other closely related taxa. Thus a taxonomist has to search for good characters which are most effective in making the distinction and separation of the species or other taxa, quick and easy. He has to keep in mind that these characters should not show wide variation among known specimens as well as intrinsic genetic variability. Also characters should not be influenced readily by the environment but must be consistent and easily seen in the specimen.


Related Discussions:- Explain process of selection of taxonomic characters

How will it impact the rest of the organs, Starting at the esophagus, trace...

Starting at the esophagus, trace the pathway of food through the system. At each organ, indicate anatomical adaptations to the general GI tract tube structure that enhance the spec

Disease occurrence due to climate change in animals, Disease occurrence due...

Disease occurrence due to climate change The movement of animal diseases across physical and political boundaries threatens food security and creates a global public co

Stages of wilms tumour , Stages of Wilm's tumour  We shall now discuss...

Stages of Wilm's tumour  We shall now discuss about the various stages of Wilm's tumour. The extent of  disease is staged according to the findings of  surgery and  the presen

Show the major proteins that constitute the sarcomere, Q. What are the majo...

Q. What are the major proteins that constitute the sarcomere? What is the function of those molecules in the muscle cells? In the sarcomere there are organized myosin and actin

Explain the failure of implant, Failure of implant The implant is cons...

Failure of implant The implant is considered a failed implant if it presents with even any one of the following features: i) Pain on function (Rule out pain due to soft tis

Define about the probiotics, Define about the Probiotics? Dietary Sourc...

Define about the Probiotics? Dietary Sources and their Mode of Action/Effects We can have specific preparations designed for probiotic use, as well as, foods. Probiotic product

How stomata position changes in some plant, How has the position of the sto...

How has the position of the stomata changed in some plants to prevent excessive water loss by transpiration? In the some plants that have leaves that receive too much sunlight

Explain about the toxicity - fat soluble vitamin, Explain about the Toxicit...

Explain about the Toxicity - fat soluble Vitamin? Because vitamin A is fat-soluble and can be stored, primarily in the liver, routine  consumption of large amounts of vitamin A

Bacterial diseases-anthrax, Anthrax Synonym              :    Wool sor...

Anthrax Synonym              :    Wool sorter’s disease Species affected    :    Cattle, sheep, goats, pig, horse and majority of the mammals. Fowls are resistant to anthr

Explain water-soluble and fat-soluble vitamins, What is the difference betw...

What is the difference between water-soluble and fat-soluble vitamins? Why can fat-soluble vitamins cause harm when ingested in excess? Water-soluble vitamins are those soluble

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd