My Authors
Read all threads
Humans are in a lineage that has been sexual—that is, sexually reproducing—for 500 million years. Uninterrupted. Once our ancestors discovered sex, not once in our lineage did we go asexual. 1/8
Our ancestors also discovered terrestriality…but some of us returned to the sea. Our ancestors co-opted swim bladders and turned them into lungs. We switched up how we eat, and move, and sense our surroundings and each other. But sex? Once we became sexual, we stayed sexual. 2/
What does it mean to be sexual, rather than asexual? It means that we combine our genomes with other individuals when we make more of ourselves. We don’t do that with our soma—our body cells. We do it with our germ line—our gametes. Gametes are how we sexually reproduce. 3/
In every sexual species on Earth, you can discern its sex by looking its gametes.

Big, sessile gametes that are rich in cytoplasm are eggs. Females have eggs.

Small, mobile gametes that are stripped of cytoplasm are sperm (or pollen). Males have sperm. 4/
Aren’t there some individuals without gametes—because they don’t yet, don’t still, or, in rare cases, they never have or will (in which case, sorry, they are not viable, evolutionarily)? Yes, there are. This does not render the gamete type = sex argument invalid. 5/
Similarly, the fact that some people have only one leg does not mean that humans are not bipedal.

The fact that some people are blind does not put the lie to the fact that we—and indeed, all Primates—are a particularly visually-dominant species. 6/
Exceptions to categories do not render the categories untrue or meaningless.

The more complex the system, the fuzzier the borders between categories are. 7/
Pretending that humans live in an ahistorical landscape is a luxury, not a right. It is the luxury of using pseudo-logic to believe that you have destroyed truths which, in fact, care not a bit what you think. It is the luxury of postmodernism. /end
Missing some Tweet in this thread? You can try to force a refresh.

Enjoying this thread?

Keep Current with Heather E Heying

Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

Twitter may remove this content at anytime, convert it as a PDF, save and print for later use!

Try unrolling a thread yourself!

how to unroll video

1) Follow Thread Reader App on Twitter so you can easily mention us!

2) Go to a Twitter thread (series of Tweets by the same owner) and mention us with a keyword "unroll" @threadreaderapp unroll

You can practice here first or read more on our help page!

Follow Us on Twitter!

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just three indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3.00/month or $30.00/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!