Thread by @FondOfBeetles

I recently tweeted about people who think I believe humans are asparagus.

This bad faith take stems (ha ha) from an analogy I’ve used to illustrate that the phenomenon of male/female is not limited to the constructions of the human brain.

Like many plants, and like humans, (some) asparagus strains are dioecious - they exist as individuals male and individual female plants. In animals, we call this set up ‘gonochorism’.

Asparagus can reproduce via the fusion of one small and one large gamete (sometimes, they reproduce asexually).

Biological convention denotes the plant morph producing the large gamete, found in the ovules, as ‘female’.

Approximately 50% of humans share this reproductive role - contribution of large gametes - with female asparagus plants.

I am among their number. Male humans are not among their number.

It has always been highly amusing to see people interpret this comparison of sexual reproduction in asparagus and humans as me saying that humans are asparagus.

Sorry, the interpretations usually look like ‘HuManS ArE AspaRaGus 🤪’

It appears many are unable or unwilling to grasp that the natural world isn’t composed only of humans and naval-gazing constructions, but is a beautiful, diverse, network of organisms, many of whom, despite outward appearances, share astonishing similarities.

Because evolution.

The way our species reproduces is an widespread Standard Operating Procedure widespread, including in asparagus plants.

As the kids say, ‘cope’.

While humans are not asparagus plants (file under: sentences I never thought I’d have to type), we make babies by the same SOP.

We do a lot of stuff using the same SOP, to be honest, from the processes underpinning the growth of a new baby to the completion of the life cycle in making a new one.

For example, we have cells, with nuclei, that contain DNA packaged into chromosomes.

From those DNA instructions emerge shared processes of replication, division, metabolism, growth, and so on.

And from that DNA comes the instructions to be a male or female plant.

Sex in asparagus is determined by genetics. They use an XY determination system, the same as humans. Female asparagus plants have two X chromosomes, males are typically XY.

Asparagus has a third sex karyotype (it has to be elicited carefully by green-fingered types). The YY karyotype gives rise to ‘super males’. They aren’t easy to discriminate from old hat XY males, but an awful lot of time and money is invested in doing so.

Because we eat male asparagus plants. Their spears are bigger. And if you can boost the number of male plants in your field, you boost your bottom line. Crossing XX females with YY males guarantees all offspring are edible and sellable XY males.

Neat.

YY asparagus plants are not a third sex, just as XYY humans (historically also called ‘super males’) are not a third sex. Both YY asparagus and XYY humans produce small gametes (pollen and sperm, respectively).

They are male individuals and karyotypes are not sex.

The human X chromosome was named for its unique properties. A quick squizz under a microscope reveals nothing visually striking about it.

Despite what some might think, it is not X shaped, except in replication. But all chromosomes are X shaped in replication, including the Y.

Asparagus Xs look a little like human Xs. Sex is an ancient phenomenon, and because - obviously - humans and asparagus plants diverged quite a while ago, there has been a lot of time for accumulation of differences.

But still, the echoes of evolutionary bonds remain.

Understanding how humans fit in the natural world is not faulty thinking, for (failed attempts at) mockery.

Knowing how and why we are similar to asparagus (not just reproductive SOPs) is mind-blowing. And understanding our differences - asparagus don’t do Twitter - equally so.