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

#tit, what three connective tissues are liquid

what three connective tissues are liquid

Differences of transposable elements in e. coli, Discuss the similarities a...

Discuss the similarities and differences of transposable elements in E. coli, yeast, plants, and Drosophila.

Describe the pulmonary artery, Q. Describe the pulmonary artery? The ma...

Q. Describe the pulmonary artery? The main pulmonary artery is seen on the PA view, as its left border forms the pulmonary bay. The right pulmonary artery runs horizontally to

Purposes of assessing growth and development in children, PURPOSES OF ASSES...

PURPOSES OF ASSESSING GROWTH AND DEVELOPMENT IN CHILDREN Before you assess the growth and development you should be aware of the purpose of monitoring. The purposes are a

What are sensory receptors, Q. What are sensory receptors? Sensory rece...

Q. What are sensory receptors? Sensory receptors are structures specialized in the acquiring of information, mechanical pressure, like temperature, pH, luminosity and chemical

Explain renal insufficiency, Renal insufficiency  Antimicrobial drugs e...

Renal insufficiency  Antimicrobial drugs excreted through the urinary tract may be toxic for patients with renal insufficiency if they are given in usual therapeutic doses, bec

How do schistosomes differentiate regarding sex separation, Q. How do schis...

Q. How do schistosomes differentiate regarding sex separation? The Schistosomes are dioecious that is the species has separated sexes, female and male individuals.

Define serum vitamin a content, Define Serum Vitamin A Content? Assessm...

Define Serum Vitamin A Content? Assessment of serum vitamin A content is the most reliable criterion Tor assessing vitamin A status. Serum levels indicative of various degrees

Vertebrates, characterstics and classification of vertebrates

characterstics and classification of vertebrates

Benefit of hypothermic, Normal 0 false false false EN-I...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

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