Sexual dimorphism: what is and examples

Sexual dimorphism refers to physical differences of the organisms of a same species for sex differentiationthat is, between male and female, but they are different from those already presented by the sexual organs.

While sexual dimorphism is more common in animals, it is important to emphasize that in the plant kingdom there are also some cases. The plants are usually monoically, that is to say that they are males and females in the same plant, but some species have males and females separately. In certain cases there is usually sexual dimorphism, presented in the size and height of plants.

Dimorphism begins to express with the arrival of the sexual maturity of an animal. This dimorphism serves for organisms of the opposite sex identify the competent couples and sexually available.

Among the factors that give rise to this differentiation is the genetic information that is expressed in sexual development and the environmental factors on which animals depend, where seasonality indicates to animals that are ready to show themselves as competent and available.

These signs are essential for sexual selection, in order to identify fertile couples and with which a genetic recombination Originator of Apt Desencend. The dimorphism process can generate deterrence, or disappointment in case of not being successful, in the opposite body to modify its behavior. This is how dimorphism is also a type of communication between animals.

We advise you to read about the reproduction function: what it consists of and why it is important.

Within sexual dimorphism we can find various types:

• Sexual dicromism: Difference in color, normally in more striking versions, to attract opposite sex. Females often prefer the most colorful males.
• Sexual dimorphism: Difference in the form of the body or one of the appendices, aimed at specific and gestation activities. For example, male crabs have a larger tenza to hit the ground and attract females through vibrations.
• Sexual DimEgetism: Difference of sizes, as a differentiating quality in polygonic species where males have to compete for females for their harem. In some species, large females represent better fertility, giving it advantage when selected.
• Sexual cyclagism: Difference in sound patterns. In some groups such as amphibians and birds, singing is important for courtship. In birds, this song denotes health of the specimen, thus attracting the male to the females.
• Sexual Difouism: Difference in intensity and light patterns. It can be used to attract the opposite sex, as for example do the adult female fireflies, or to scare away threats, which is the case of the male fireflies in the larval stage.
• Sexual Diolpism: Difference in defense appendices, especially in females to defend their nest or habitat.
• Sexual dimorphism of the brain: Differences in animals behavior, whether sexual behaviors or to protect their offspring. They occur by structural changes in specific sites within the brain, where hormones such as estradiol play an important role.
• Behavioral sexual dimorphism: Other animals that do not have such an advanced headache develop their behavior with responses to chemical or visual signals. They can also have differences in their sexual behaviors.
• Dietary sexual dimorphism: Differences in eating behavior, such as the case of sexual dimorphism in lions. The females are the ones who hunt the food while the males wait.

Finally, we have just clarified this concept with some Examples of easy sexual dimorphism:

Human sexual dimorphism

The human has a marked sexual dimorphism that begins to manifest from puberty and is what we recognize as sexual attraction. While each person has their tastes and today there are many factors that come into play, biologically speaking there are differentiating modifications and standards between men and women. Women begin to accumulate fat in thighs, hips and buttocks, while, generally, men are larger, usually 5 to 13% more. This proportion in size is also visible in hominoid monkeys. Another important feature, which is also common for sexual dimorphism in mammals, is the development of visible mammary glands.

Here you can learn better to mammals: characteristics, types and examples.

Gallo and chicken

Sexual dimorphism in birds is presented by the presence of having more colorful plumages. This is the case of the sexual dimorphism of the rooster and the chicken, where the former has more striking colored feathers, in addition to being larger than the chicken, with spur in the legs and high ridges in the head. They also have sexual cyclagism, because the rooster sings and the chicken does not.

Know more about the characteristics of birds and classification of birds reading these other posts

Beta fish

Beta fish are a clear example of sexual dimorphism in fish. The males have colorful lines with lit colors and large sizes as veils. The females show reproduction stripes, which indicate that ready to reproduce, and their tails are much smaller than those of males. They also have dimorphism in their behavior, where males violently fight between them. In the female courtship process, they swim around to expose their impressive queues.

Learn with this other article about the characteristics and classification of fish.

Religious mantis

Sexual dimorphism in invertebrate animals is highly developed and, in fact, there is no homomorphism. An excellent example are Religious mantis. After intercourse the females kill the males and then eat them. Here we have a case of sexual dimorphism of behavior. Even males demonstrate a modification in behavior. There is also sexual digmemetism dimorphism, because the female is bigger. If you are surprised by this curious animal, do not miss this other post about the doubt: is the religious mantis poisonous?

You can learn more about this other group of animals, to which the mantis belong, reading this article about the classification of insects.

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