This article: https://academic.oup.com/biolinnean/article/120/1/1/2864987

Eggs can only be fertilized by sperm; sperm can only fertilize eggs

If eggs can only be fertilized by sperm and sperm can only fertilize eggs, this would show that there are two separate haploid sexes, even if this does not distinguish which haploids are female and which are male. Such a criterion could be referred to as polarity of gametes, a notion that parallels discussions of (non-existent) diploid sex complementarity and dualism between females and males (Scheibinger, 1993; Hird, 2004). However, in taxa with central fusion and terminal fusion, which are known from many eukaryotes, eggs or egg nuclei fuse with other eggs or egg nuclei (Stenberg & Saura, 2009; Booth et al., 2014). Although much rarer, two sperm pronuclei fuse to form a zygote, for example in the androgenetic stick insect Bacillus grandii (Tinti & Scali, 1992). Although we do not know whether it is possible in such species for all eggs to fuse with all other eggs or all sperm to fuse with all other sperm, at least some eggs can fuse with one another and some sperm can fuse with one another. Therefore sexes do not always correspond with mating types. There is no universal complementarity between female and male gametes.

I highlight one portion of the article. Please read the rest that claims eggs are not larger than sperm in all species, and anisogamy is a poor, exaggerated way of categorization yourselves.

This portion I highlight claims that because sometimes two sperm "fuse" or "create" a zygote, and two eggs "fuse" or "create" a zygote, just as an egg and a sperm fuse or "create" a zygote, the "differences" between sperm and egg, male and female, are arbitrary and not universal. The differences could have evolved between two sperm or two eggs, because two sperm or two eggs can do the same thing a sperm and egg do.

They give the example of taxa with central fusion and terminal fusion, the androgenetic insect Bacillus grandii in particular.

The examples are parthenogenesis, gynogenesis and androgenesis. There are sperm-"fusion" androgenesis in which two sperm "fuse" or "create" a zygote, such as this bee over here which was the result of androgenesis, the "fusion" of two sperm: https://www.forbes.com/sites/grrlscientist/2018/11/28/a-honeybee-with-two-fathers-and-no-mother/#740bc6f84405

https://royalsocietypublishing.org/doi/10.1098/rsbl.2018.0670

Their conclusion is: the differences between sperm and egg, male and female, are not universal, and do not apply to all species, therefore "sperm and egg, male and female, are socially constructed, illusory categories made up by humans"

It makes sense that the differences between sperm and egg, male and female, should be universal and apply to all species.

Exceptions disprove a rule, and indicate a deviation from the "norm", a challenge to a rule.

If, for instance, there were no universal differences between "living" and "nonliving", and there were exceptions, the conclusion would be the categories of "living" and "nonliving" are illusory and don't exist outside the human mind.

I've seen liberals and TRAs claim "living" and "nonliving", as well as "specie" itself, are illusory social constructs ...

To quote the TRA article again:

Several researchers have convincingly demonstrated that there are no universal differences between diploid females and males (Fausto-Sterling, 1985), a finding utterly consistent with intersex, trans-sex, and environmental sex determination in many eukaryotes. Therefore, the focus here has been on haploid and gametic differences between females and males.

The more organisms that we examine, the more we are convinced of the arbitrariness of how humans have classified and designated the two sexes, female and male

Although we typically think of females and males as being well-defined categories across all three eukaryotic supergroups that contain massively multicellular taxa, namely animals, plants, and brown algae (Ophistokonta, Archaeplastida, and Heterokonta), all of the above criteria for differences between females vs. males are illusory and/or inconsistent. Amongst eukaryotes, there is no essential/universal difference between females and males.

What are your arguments against this liberal TRA article?

If you happen to be a biologist, or knowledgeable in the area, please share your knowledge with me