Key Terms in Evolutionary Biology of Sex, Gender, and Sexuality: Sex vs. Gender

= Sex vs. Gender =

Definitions
Sex is determined biologically according to the size of the gametes produced by an individual.1 Gametes are reproductive cells, also known as sex cells.3undefined There are two types of gametes, sperm and egg (ovum). 3

There are only two sexes: male and female. Males produce small gametes—sperm, and females produce large gametes—eggs.3 This definition is inflexible and ubiquitous throughout the animal and plant kingdoms.1 In biology, as applied to all species, human and non-human, Gender is determined by traits or characteristics including appearance, behavior, and life history of a sexed body2, and how these are utilized to fulfill an individual’s sexual role in any given society.1undefined

Because the word gender refers to social categories, it is a much broader and versatile word than the sex. The words “men” and “women” are two social classifications.1It is people who determine what defines a man or woman, so what classifies as each gender may be different in every society. These distinctions dictate which roles a person plays in their society, the groups in which they may be included, and with whom it is acceptable to have sex or marry.1

The words “male” and “female” are biological categories, but unlike the social categories, there is no flexibility between these categories.1 Technically, the meanings of male and female don’t change and are used in reference to all living organisms.1 However, in everyday conversation, these terms are often misused3.

Scientific background &amp; History
Often times we think of the word gender as a term that applies to humans alone. However, there are several applications of the word not only in the biological sphere, but in social, idiomatic, and linguistic spheres as well.

Many languages use a system of grammatical gender to classify nouns.6 Some languages have masculine and feminine words, such as the Spanish language. In some languages, German for example, also have a class called neuter, meaning neutral.6

Debates &amp; Controversies
Common Misconceptions &amp; Misleading Stereotypes

There are many misconceptions as well as stereotypes associated with the terms sex and gender. Mostly, these occur when one’s concept of a gender is the same as one’s concept of sex. It is also very common to assume that in a single body, the sex and gender must be congruent. Below are listed a few examples of typical sex/gender misconceptions. (Keep in mind the italicized sentences are false or not always true).

There are only two genders that correspond to the two sexes, and an organism is male or female, remaining so its entire life. This is perhaps the most common delusion people have about the natural world. Even before taking biology class in school, people are raised to believe that there are only two genders, male and female; this is a mistake. Male and female are the two sexes. 1 Men and women are words that describe gender.1 However, gender is by no means limited to man or woman, nor is a body limited to only one gender for life. 1 In fact, the most common body form in plants and animals is for an individual to be both male and female at the same time or at different times throughout its life.1 In other words, there exist only two sexes, but that does not mean that bodies are always one or the other.

Males and females have XY or XX chromosomes, respectively. Although in humans this is most often the case, it is not always the case. In some bird species, males have XX and females have XY. In some creatures, such as turtles, sex is determined by the temperature of the egg during incubation.1

''Females give birth and lactate, and males have penises. '' In many species, it is the male who incubates the eggs or tends the nest of his offspring.1 It is also true that in some species of fruit bat, males have mammary glands that produce milk.1 Probably the most shocking of all, is the myth that only males have penises. Both females and males of the spotted hyena species have penises that function as both organs for copulation and for urinary excretion.2

In addition to the misconceptions some people have concerning the classification of sex and gender in the natural world, there is also much debate over the determinants of gender among different social spheres. Men and women are not the only possible genders either. Hermaphrodites4 are an exceptionally common gender, mostly in fish and plants, but often in other species too, even humans.2

The traits that make an individual a man or a woman change drastically among separate cultures and within each culture as well. For example, in the United States, the consensus is that if you have a penis, you are considered a man. On the other hand, if you are from the South Pacific Vanuatu Islands, you are considered a man only once you have bungee-jumped off a 100-foot tower made of reeds and vines.5 Within these cultures there may also be social circles with different definitions of male and female, such as political parties.

Additional notes (subscripts)
1.  Gametes are haploid cells meaning they contain 23 chromosomes, which is half the amount of a normal diploid cell, containing 46 chromosomes. During sexual reproduction, the egg and sperm combine to create a single diploid cell.4 2. A “sexed” body is a body that is biologically categorized as a “male”, producing small gametes, or “female”, producing large gametes.1 '''3. ''' Misuse of the biological categories, male and female, in place of the social categories, man and woman, is called “essentialism”. 1 4.  Hermaphrodite – a body who makes both gametes at some point during their life.2

References (superscripts)
1.  Roughgarden, Joan, Evolution’s Rainbow, The Regents of the University of California, 2004, 2009. Ch.2 “Sex versus gender”.

2.  Roughgarden, Joan, Evolution’s Rainbow, The Regents of the University of California, 2004, 2009. Ch.3 “Sex within bodies”.

3.  MacDonald, Kurt D., 2007. Evolution &amp; Ecosystem Biology Course Book and Lecture Notes, Kent Denver School. Ch.3 “Mendelian Inheritance”.

4.  MacDonald, Kurt D., 2007. Evolution &amp; Ecosystem Biology Course Book and Lecture Notes, Kent Denver School. Ch.4 “Reproduction/Meiosis”.

5.  Gredose, Alexandra, 2008. The five most terrifying rites of manhood from around the world, Cracked.com. http://www.cracked.com/article_16313_5-most-terrifying-rites-manhood-from-around-world.html.

6.  Wikipedia page last modified 18 March 2010. Gender, Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Gender.

Author
Zoe Bidell