Genetics and Evolution - Essay Example

Only on StudentShare

Extract of sample
Genetics and Evolution

Thus in such situations the characters used to recognise the species becomes merely diagnostic, not distinctive. Biologically speaking, these are a connected series of the species in neighbouring areas which interbreed with two end populations which are too phenotypically and geographically separated that they cannot interbreed. These two genetically and phenotypically diverse populations which represent the end populations may exist in the same geographic region, yet due to genetic and phenotypic diversity would not interbreed. As an example, the case of Larus gulls can be taken, the different species of which form a ring around the North Pole. The Lesser Black-beaked Gulls in Siberia form a part of this ring, and although they descend from the same species, adjacent Herring gulls are so different from them that they do not interbreed.
Earnst Mayr's Biological species concept tends to recognise species based on defined phenotypic characters. Mayr defined species as groups of interbreeding populations, which do not reproduce across other species. This builds in a concept of reproductive isolation from other such groups. Particular species specific phenotypic characters or attributes prevent interbreeding with other species. ...
Download paper


Ring species is defined by a phenomenon of evolution where two species are apparently present at one place, but these two species are connected by a series of forms, existing in places connected geographically like a ring. The most important feature of ring species is that despite arbitrary similarities, no phenotypic characteristics can be used to divide this ring into two species…
Author : runolfssonjuwan

Related Essays

Processes of Evolution
This is also the rationale behind the arrival of variations in the species of organisms through time. The genius of evolution lies in the fact that although organisms have obviously changed though time, a lot of their features remain strikingly comparable to something from a different age. (The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California, 2008)
4 pages (1004 words) Essay
Genetics Essay
The expected phenotype of F2 generation would be 75% tall plants and 25% short plants. In F2 generation 25% of plants would be tall but would be homozygous for their trait of tallness. Another 50% of plants would also be tall but would be heterozygous for their trait of tallness while the remaining 25% of would be short and would be recessive for their trait.
4 pages (1004 words) Essay
Evolution of colouration in bird eggs
One key fact states that the more diversified a population becomes, the more likely it is to survive as a species. This increases its ability to occupy more territory and gain access to more sustenance, or to spread itself out and become more inconspicuous among predators. Several species of birds demonstrate this type of variation at the embryonic stage. The eggs they lay are coloured or spotted in particular ways, the complete reasons for which have been somewhat elusive to researchers for some time. In fact, birds are the only species that produce pigmented egg shells (Gosler, et al. 2005,...
11 pages (2761 words) Essay
Human Genetics
This would make both of his parents Dd genetypes.
6 pages (1506 words) Essay
The F1 phenotypic ratio is 3:1:3:1, rough yellow, smooth yellow, rough white, smooth white. The genotypic ratio is 1:1:2:2:1:1. All combinations have occurred, but two showed elevated results according to genotypic and phenotypic ratios.
4 pages (1004 words) Essay
This was done to obtain the RAD51+/- cells (EMBO, 1998). Then, the RAD51+/- cells have been transpected with conditional human Rad51 expression constructs to obtain RAD51+/- cells carrying the constructs at random sites on the chromosome (RAD51+/-/HsRAD51)." (, 1998) Finally, the RAD51 construct that contained the blasticidin was then transpected into "several RAD51+/-/HsRAD51 clones to isolate RAD51-/-/HsRAD51 clones." (EMBO, 1998)
3 pages (753 words) Essay
Got a tricky question? Receive an answer from students like you! Try us!