sexual dimorphism

Examples of sexual dimorphism in the following topics:

• Sexual Selection

  • Sexual selection, the selection pressure on males and females to obtain matings, can result in traits designed to maximize sexual success.
  • The selection pressures on males and females to obtain matings is known as sexual selection.
  • These differences are called sexual dimorphisms and arise from the variation in male reproductive success.
  • Sexual dimorphism varies widely among species; some species are even sex-role reversed.
  • Discuss the effects of sexual dimorphism on the reproductive potential of an organism

• Hypothalamus

  • The hypothalamus affects the endocrine system and governs emotional behavior, such as anger and sexual activity.
  • The defeated animal has an increase in Fos levels in sexually dimorphic structures.
  • Several hypothalamic nuclei are sexually dimorphic, i.e. there are clear differences in both structure and function between males and females.
  • Some differences are apparent even in gross neuroanatomy: most notable is the sexually dimorphic nucleus within the preoptic area.

• Phylum Rotifera

  • Rotifers are dioecious organisms (having either male or female genitalia) and exhibit sexual dimorphism (males and females have different forms).

• Micturition and the Micturition Reflex

  • Due to sexual dimorphism, and the positions where the urethra ends, males and females often use different techniques for urination.

• Phylum Echinodermata

  • Echinoderms are sexually dimorphic and release their eggs and sperm cells into water; fertilization is external.
  • In some species, the larvae divide asexually and multiply before they reach sexual maturity.

• Phylum Nemertea

  • Animals in phylum Nemertea show sexual dimorphism, although freshwater species may be hermaphroditic.

• Early Hominins

  • For example, sexual dimorphism was more exaggerated than in modern humans.

• Characteristics and Evolution of Primates

  • The very arboreal gibbons are smaller than the great apes; they have low sexual dimorphism (that is, the genders are not markedly different in size); and they have relatively longer arms used for swinging/brachiating through trees.

• Genus Homo

  • Its degree of sexual dimorphism was less than earlier species, with males being 20 to 30 percent larger than females, which is close to the size difference seen in our species.

• Defining Sex, Gender, and Sexuality

  • "Human sexuality" refers to people's sexual interest in and attraction to others, as well as their capacity to have erotic experiences and responses.
  • People's sexual orientation is their emotional and sexual attraction to particular sexes or genders, which often shapes their sexuality.
  • The biological and physical aspects of sexuality largely concern the human reproductive functions, including the human sexual-response cycle and the basic biological drive that exists in all species.
  • Social aspects deal with the effects of human society on one's sexuality, while spirituality concerns an individual's spiritual connection with others through sexuality.
  • The standard model has been criticized for saying that humans are sexually dimorphic: this means each and every human being is either male or female, thus leaving out those who are born intersex.