<div class="thumbinner" style="width: 182px;" class="thumbinner"><img width="180" height="260" class="thumbimage" alt="Schematic representation of DNA, the primary genetic material." longdesc="/wiki/Image:DNA-structure-and-bases.png" src="http://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/DNA-structure-and-bases.png/180px-DNA-structure-and-bases.png" longdesc="/wiki/Image:DNA-structure-and-bases.png" alt="Schematic representation of DNA, the primary genetic material." class="thumbimage" />

<div class="magnify" style="float: right;" class="magnify"><img width="15" height="11" alt="" src="http://en.wikipedia.org/skins-1.5/common/images/magnify-clip.png" alt="" /></div>

<p>While organisms may vary immensely in appearance, habitat, and behaviour it is a central principle of biology that all life shares certain universal fundamentals. A key feature is reproduction or replication. According to <a href="httpjavascript:void(0);//www.superiorpapers.com*1256199523180*/">paper writing</a>, the entity being replicated, the replicator, in the past was considered to be the organism during the time of Darwin, but since the 1970s increasingly reduced to the scale of molecules.<sup class="reference" id="_ref-1" class="reference">[2]</sup> All known life has a carbon-based biochemistry, carbon is the fundamental building block of the molecules that make up all known living things. Similarly water is the basic solvent for all known living organisms. While all these things are true of all organisms observed on Earth, in theory alternative forms of life could exist and some scientists do look at alternative biochemistry.</p>

<div class="thumbinner" style="widthWIDTH: 302px;" ><img class="thumbinnerthumbimage"><img height="148" width="300" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Fitness-landscape-cartoon.png/300px-Fitness-landscape-cartoon.png" longdesc="/wiki/Image:Fitness-landscape-cartoon.png" alt="In population genetics the evolution of a population of organisms is sometimes depicted as if travelling on a fitness landscape. The arrows indicate the preferred flow of a population on the landscape, and the points A, B, and C are local optima. The red ball indicates a population that moves from a very low fitness value to the top of a peak." classwidth="300" longdesc="/wiki/Image:Fitness-landscape-cartoon.png" src="thumbimagehttp://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Fitness-landscape-cartoon.png/300px-Fitness-landscape-cartoon.png" />

<div class="magnify" style="floatFLOAT: right;" class="magnify"><img height="11" alt="" width="15" src="http://en.wikipedia.org/skins-1.5/common/images/magnify-clip.png" alt="" /></div>

<p><em>Main <a href="http://webspacehosting.com">web page</a> articles:</em> <strong>Evolutionary biology</strong>, Biodiversity, Botany, Zoology is concerned with the origin and descent of species, as well as their change over time, and includes scientists from many taxonomically-oriented disciplines. For example, it generally involves scientists who have special training in particular organisms such as mammalogy, ornithology, or herpetology, but use those organisms as systems to answer general questions about evolution. Evolutionary biology is mainly based on paleontology, which uses the fossil record to answer questions about the mode and tempo of evolution, as well as the developments in areas such as population genetics and evolutionary theory. In the 1990s, developmental biology re-entered evolutionary biology from its initial exclusion from the modern synthesis through the study of evolutionary developmental biology. Related fields which are often considered part of evolutionary biology are phylogenetics, systematics, and taxonomy.</p>