For decades, conservative commentators have claimed that non-heterosexual orientations are unnatural. A notable example is Michael Levin's 1984 article, "Why Homosexuality is Abnormal," published in the philosophy journal The Monist. Levin argues that homosexuality is undesirable due to its mechanical incompatibility with heterosexual reproduction, asserting that male and female genitalia are “made for each other.”

Throughout history, whether through religious or scientific lenses, societal norms have often been employed to denounce queerness. However, the notion that heterosexuality is the only natural orientation lacks biological support. There is no evidence to substantiate that homosexuality is abnormal, nor is there proof that heterosexuality as an identity is inherently natural.

A common rebuttal from the LGBTQIA2+ community is the observation of diverse sexual and gender behaviors within the animal kingdom. Numerous species—nearly 1,000—exhibit same-sex interactions, demonstrating that sexual orientation in animals does not mirror human constructs.

For instance, male giraffes frequently engage in same-sex behaviors, often participating in a ritualistic display known as “necking,” which sometimes leads to anal intercourse. Adam Rutherford, in his work Humanimal, notes that most sexual encounters among giraffes involve these same-sex interactions.

Gender fluidity is also prevalent among various species. The Banana Slug, for example, is hermaphroditic, possessing both male and female reproductive organs. Although some animals may exhibit intersex traits, the term "hermaphrodite" is now considered outdated and offensive; "intersex" is preferred. True human hermaphroditism, where individuals possess fully functional male and female reproductive systems, has not been documented.

Sequential hermaphroditism is another fascinating phenomenon observed in species like clownfish, where individuals can change sex based on social dynamics. When a female clownfish is lost, the dominant male will transform into a female, allowing the next largest male to assume the role of the new dominant male.

Additionally, Spotted Hyenas possess unique genital structures that blur traditional definitions of male and female. Their anatomy includes a clitoris that resembles a penis, complicating the identification of sexes based solely on genitalia. As zoologist Kay E. Holekamp noted in The New York Times, it’s not uncommon for individuals mistakenly identified as males to later be observed nursing cubs.

While these discussions often conclude with assertions that queerness is natural, they often overlook a deeper inquiry: Is heterosexuality, characterized by exclusive attraction to the opposite sex, genuinely natural?

Evidence suggests otherwise, especially when examining our closest relatives, the Bonobos. Sharing 98% of our DNA, these great apes display a matriarchal society centered on communication and sociability, frequently using sexual interactions—including same-sex encounters—to manage social tensions. As noted by Melissa Hogenboom in BBC, Bonobos are significantly less aggressive than chimpanzees, often resolving conflicts through sexual behaviors.

Chimpanzees, while sharing similar DNA, exhibit a more violent and territorial nature. However, they too engage in same-sex activities, as documented by researchers. Such findings reveal that even within traditionally heterosexual species, same-sex interactions are not uncommon.

The evolutionary biology surrounding these species challenges the conservative narrative that heterosexuality is the only path to reproduction. Giraffes, for instance, display higher rates of same-sex interactions without jeopardizing species survival.

Moreover, a historical lens reveals that human sexuality has always encompassed a spectrum beyond mere heterosexuality. Queer individuals have existed across cultures and eras, influencing societies and contributing to literature, art, and mythology.

Recent polling indicates a growing acceptance of LGBTQ identities, with a Gallup poll showing that 5.6% of Americans identify as LGBT, rising to 15.9% among Generation Z. This generational shift highlights the impact of diminishing stigma surrounding queerness, suggesting that many individuals may simply embrace their authentic selves.

Thus, while heterosexual relationships will continue, the identity of heterosexuality itself is a social construct, not a biological necessity. The animal kingdom showcases a rich tapestry of sexual behaviors, supporting the idea that heterosexuality is not the sole means of survival or reproduction.

In conclusion, the argument positing heterosexuality as a natural default lacks robust scientific backing. Our understanding of sexuality is evolving, and the recognition of diverse sexual orientations is crucial for a more inclusive society.