Understanding Rhythms & Their Adaptive Significance – Article Example
Understanding Rhythms & Their Adaptive Significance If one considers any quantitative biological phenomenon at random from egg-laying to food-gathering in any living species and draw a sample to record data then it will be observed that the activity exhibits a repetitive linkage with the day and night cycles. Thus these repetitions may be termed as daily rhythms. The descriptive literature provides that these daily rhythms are amazingly common among living beings. They have been evident in all main groups of living organisms from protozoa to mammals as well as at all organizational levels within a species. For example, if examined closely the human births are also rhythmic as there are more chances of birth in early morning than in early evening. Moreover, body temperature, CNS electrical transmission, metabolic rate, blood constituents’ concentration, glycogen levels in liver, urine volume and the cell division exhibited by various tissues can be accounted as daily rhythms. Certain rhythms are found to exhibit sensitivity towards certain agents (pharmaceutical agents) and are called ‘sensitivity rhythms’. Some of these daily rhythms are called circadian rhythms and are referred to be innate and inherited.
The omnipresence of circadian rhythms at various organizational levels as well as phylo-genetically within organisms indicates strongly their common adaptive significance. It has been found that the circadian rhythms may exhibit adaptive nature in two major categories. Firstly in attempt to maintain a synchronization of the particular rhythmic activity with its external rhythmic environmental factors such as temperature, humidity, ecological community and light. For example bees ensure that their visit t specific flowers are timed appropriately so that they reach the flower at the moment it begins to secrete nectar and such a synchronization provides adaptive value to either of the species. Similarly, the reproductive cycles of various organisms are synchronized with events in the environment that impact the existence of offspring. This synchronization is attained by physiological responses to the varying day length depending upon season (photoperiod). Photoperiodism relies upon the organism’s capability to gauge time. Species also decline competition by phasing differentially to the environmental cycles.
The second major category concerned with the circadian rhythms is their role in the sustenance of synchrony between several physiological events occurring within an organism by appropriately phasing with one another. For examples the substrates for energy sources, biochemical reactions, and information conveying molecules must be located at their required places at right time so that the tissues and organs are integrated within an efficiently performing organism. Thus, it can be said that the biological clocks perform their obligations while ensuring synchronization within the different internal systems as well as with the external events (Menaker 687).
Menaker, Michael. “Biological Clocks.” BioScience 19.8 (1969): 681-689. Print.