Sex ratio in the context of Indian Singaporean

Sexual selection is a mechanism of evolution in which members of one sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males.

The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald Fisher in the early 20th century. Sexual selection can lead males to extreme efforts to demonstrate their fitness to be chosen by females, producing sexual dimorphism in secondary sexual characteristics, such as the ornate plumage of birds-of-paradise and peafowl, or the antlers of deer. Depending on the species, these rules can be reversed. This is caused by a positive feedback mechanism known as a Fisherian runaway, where the passing-on of the desire for a trait in one sex is as important as having the trait in the other sex in producing the runaway effect. Although the sexy son hypothesis indicates that females would prefer male offspring, Fisher's principle explains why the sex ratio is most often 1:1. Sexual selection is widely distributed in the animal kingdom, and is also found in plants and fungi.

The human sex ratio is the ratio of males to females in a population in the context of anthropology and demography. In humans, the natural sex ratio at birth is slightly biased towards the male sex. It is estimated to be about 1.05 worldwide or within a narrow range from 1.03 to 1.06 males per female at birth. The sex ratio for the entire world population including all ages is approximately 101 males to 100 females as of 2024.

The sex ratios at birth and of the total population are affected by various factors including natural factors, exposure to pesticides and environmental contaminants, war casualties, effects of war on men, sex-selective abortions, infanticides, aging, gendercide, problems with birth registration and sex differences in life expectancy.

Gender inequality in India refers to health, education, economic and political inequalities between men and women in India. Various international gender inequality indices rank India differently on each of these factors, as well as on a composite basis, and these indices are controversial.

Gender inequalities, and their social causes, impact India's sex ratio, women's health over their lifetimes, their educational attainment, and even their economic conditions. It also prevents the institution of equal rape laws for men. Gender inequality in India is a multifaceted issue that primarily concerns women, but also affects men. When India's population is examined as a whole, women are at a disadvantage in several important ways. Although the constitution of India grants men and women equal rights in theory, gender disparities remain.

The sexy son hypothesis in evolutionary biology and sexual selection, proposed by Patrick J. Weatherhead and Raleigh J. Robertson of Queen's University in Kingston, Ontario in 1979, states that a female's ideal mate choice among potential mates is one whose genes will produce males with the best chance of reproductive success. This implies that other benefits the father can offer the mother or offspring are less relevant than they may appear, including his capacity as a parental caregiver, territory and any nuptial gifts. Fisher's principle means that the sex ratio (except in certain eusocial insects) is always near 1:1 between males and females, yet what matters most are the female's "sexy sons'" future breeding successes, more likely if they have a promiscuous father, in creating large numbers of offspring carrying copies of her genes. This sexual selection hypothesis has been researched in species such as the European pied flycatcher (Ficedula hypoleuca).

Fisher's principle is an evolutionary model that explains why the sex ratio of most species that produce offspring through sexual reproduction is approximately 1:1 between males and females. A. W. F. Edwards has remarked that it is "probably the most celebrated argument in evolutionary biology".

Fisher's principle was outlined by Ronald Fisher in his 1930 book The Genetical Theory of Natural Selection (but has been incorrectly attributed as original to Fisher). Fisher couched his argument in terms of parental expenditure, and predicted that parental expenditure on both sexes should be equal. Sex ratios that are 1:1 are hence known as "Fisherian", and those that are not 1:1 are "non-Fisherian" or "extraordinary" and occur because they break the assumptions made in Fisher's model.

Indian Singaporeans are Singaporeans of Indian or broader South Asian ancestry. As of the 2020 census, they constitute approximately 9.0% of the country's residents, representing the third largest ethnic group in Singapore. In Singapore, "Indian" is an umbrella term defined in both geographical and ethnic-cultural contexts as pertaining to South Asia and bears no necessary relation to the contemporary Republic of India. Some Singaporeans of South Asian ancestry would simply just consider themselves "Singaporean", viewing themselves as distinct from the "India Indians" in terms of culture, identity and social reality.

The historical presence of ancient India influenced the indigenous Malay culture long before the founding of modern Singapore by the British Empire in 1819. Early Indian settlement was largely transient, composed primarily of male workers and soldiers. By the mid-20th century, however, the community had become more established, exhibiting a balanced gender ratio and a diversified age distribution. This period marked the emergence of a cohesive Indian Singaporean identity within the evolving social fabric of the island.

William Donald Hamilton FRS (1 August 1936 – 7 March 2000) was a British evolutionary biologist, recognised as one of the most significant evolutionary theorists of the 20th century. Hamilton became known for his theoretical work expounding a rigorous genetic basis for the existence of altruism, an insight that was a key part of the development of the gene-centered view of evolution. He is considered one of the forerunners of sociobiology. Hamilton published important work on sex ratios and the evolution of sex. From 1984 to his death in 2000, he was a Royal Society Research Professor at Oxford University.

Richard Dawkins has written that Hamilton was "the greatest Darwinian of my lifetime".

Mandi (formerly known as Mandav Nagar) is a major city and a municipal corporation in Mandi District in the Indian state of Himachal Pradesh. It is situated 145 kilometres (90 mi) north of state capital, Shimla in the north-west Himalayas at an average altitude of 880 m (2,890 ft) Mandi is connected to the Pathankot through National Highway 154 and to Manali and Chandigarh through National Highway 5. Mandi is approximately 163 km (101 mi) from Chandigarh, the nearest major city, and 395 km (245 mi) from New Delhi, the national capital. In the 2011 Indian census, Mandi had a population of 26,422. Mandi district is currently the 4th largest economy in the state. Mandi has the second highest sex ratio of 1013 females per thousand males, in the state.

It serves as the headquarters of Mandi District and Zonal Headquarters of central zone including districts namely Kullu, Bilaspur, and Hamirpur. As a tourist place, Mandi is often referred to as "Varanasi of Hills" or "Choti Kashi" or "Kashi of Himachal". Also, Mandi is the starting point for a trek of the region, Prashar lake trek. From Mandi, trekkers go to Bagi village, which serves as the base village for Prashar lake. Indian Institute of Technology (IIT) Mandi is a premier institute located 15 kilometres (9.3 mi) from Mandi town.

Singaporean Chinese or Chinese Singaporeans (simplified Chinese: 新加坡华人/华裔新加坡人; traditional Chinese: 新加坡華人/華裔新加坡人; pinyin: Xīnjiāpō Huárén / Huáyì Xīnjiāpōrén) are Singaporeans of Han ancestry. As of the 2020 census, they constitute 75.9% of the resident population, making them the largest ethnic group in Singapore. In Singapore, "Chinese" is an umbrella term defined in both geographical and ethnic-cultural contexts as pertaining to Greater China and bears no necessary relation to the contemporary People's Republic of China, whose citizens are classified separately when in Singapore. As a result, some Singaporeans of Han ancestry would simply just consider themselves "Singaporean", viewing themselves as distinct from the "China Chinese" in terms of culture, identity and social reality.

Evidence of Chinese people trading with and settling among local populations in Singapore dates as early as the 10th century. Prior to the establishment of Singapore as a British trading port, the island was home to a small community of around 120 Malays and 20 to 30 Chinese, mostly traders. The colonial period saw a substantial influx of male Chinese migrants, who often returned to their families in China after earning sufficient income. Over time, more ethnic Chinese arrived in Singapore such as the samsui women and other economic migrants. This led to a more balanced gender ratio and a diversified age distribution, which formed the bulk of the Singaporean Chinese population known today.