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How does the process by which organisms with an advantageous heritable trait tend to increase in numbers in future generations; but organisms that lack an advantageous heritable trait tend to decrease in numbers in future generations?

Hi Kierstyn,

A heritable trait becomes advantageous only if it helps the animal to adapt and survive in its environment. However great a trait, if it does not help the animal to gain survival advantage, it will dwindle away. That said, let us look at 2 scenarios.
1. One species with survival advantage over another species-
2. One animal within a species with survival advantage over its kindred/fellow animals of the same species.
1. if a particular heritable trait allows the species to say- tolerate a particular vegetation that grows abundantly in its environment, while the other species cannot tolerate it. Then this animal will have no competition and thrive under conditions of other food scarcity and continue to mate and produce. In due course of time, this animal species increases in number and outnumbers other species.
2. Within a species, the competition is not only for food but also mate. In this case, one animal with physical strength or smarter strategy or just a colorful look, nest building ability etc will help this animal to be one up over its less smarter or a weaker fellow animal. Thus the stronger one will not only eat better but may also win a mate while other males may not have a chance to mate. This will result in offsprings of this 'alpha' animal being more in number of which some may inherit the advantageous traits and pass it on further to its next generation. This way, the gene pool will consist more of the genes passed on from the animal which had an advantage. In due course of time, descendants of other weaker animals may totally be wiped out.
THus a combination of genes that confer adaptability, and  sustained favorable environment lead to increase in its number that others.



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Thanemozhi Natarajan


Answers in Genetics, genomics, cytogenetics of syndromes, congenital anomalies, cancer, clinical genomics and interpretation of omics data.


More than 10 years. Doctoral research thesis on Congenital anomalies and cytogenetics, Recurrent reproductive failure and chromosomal abnormalities. Postdoctoral experience in Breast cancer research. Current: Clinical Genomics and Pharmacogenomics.


Cancer Cell International, Cancer Epidemiology Biomarkers and Prevention, Breast cancer research and treatment, Indian Journal of Pediatrics, BMC Proceedings, Pharmacogenetics and Genomics, Human Molecular Genetics, Frontiers in Genetics, Cancer Biomarkers.

PhD Biomedical Genetics

Awards and Honors
University Grants Commission Award for pursuing PhD level research (India); Travel awards to attend conferences.

Past/Present Clients
Post doctoral experience Cancer research, molecular epidemiology Current: Clininical Genomics and Pharmacogenomics

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