In a radical departure from the plant lineage, our ancestors—the Unikonts—simplified their propulsion system. They stopped using two “pulling” flagella and narrowed it down to a single motor. This made the cell more streamlined and paved the way for more specialized movement. While some Unikonts (like our cousins the Amoebas) eventually gave up on flagella altogether to “crawl” by oozing their bodies, our direct line stayed committed to the efficiency of the single-propeller design.
Author note.
Explore voice = Exploratory style. Very punchy. Personal, and lively using “me,” “you,” “us,” and “I” freely.
I want you to feel me right there with you. We use “I” and “me” and “us” without apology. If the Explain voice is a bridge, the Explore voice is the hike we take across it. It is lively, reflective, and sometimes a bit raw. It is the sound of a shared exploration where I lead you by the hand, but we both discover the view at the same time.
This is where I get to think out loud. Not with definitions, we aren’t just looking at the facts; we are looking at how they feel and what they mean for our lives. I’m talking to you about what I’ve found and what I’m still figuring out. It is engaging because it is real, and it is reflective because it is honest.
The goal is real advice and enjoyable reading. I want to land on something you can actually use. It’s about being direct, being punchy, and making sure that by the time we reach the end of the page, we’ve both found something worth keeping.
And now the piece.
Unikonts: Single-Motor flagella Reform
~1.3 Billion Years Ago (+/- 100 million)
Transition to a Single Flagellum
- Here's the key idea. About 1.3 billion years ago, our animal-fungi ancestor stopped using two pulling flagella and narrowed it down to a single motor.
- Finally, the core takeaway. By 1.3 billion years ago, our animal-fungi ancestor, the Unikonts, stopped using two pulling flagella and narrowed it down to one. This single motor will evolve over the next 100 million years or so into a true Posterior Flagellum. The distinquishing cell trait that some mushrooms and humans share today.
That Science Story,
was first published on TST 2 months ago.
The flashcard inspired by it is this.
All this is part of the broader TST project.
These short pieces do the quiet work of verification, ensuring that ideas remain grounded in reliable scholarship rather than repetition or assumption.
Ideas here are not replaced when they evolve—they are refined, annotated, and revisited.
The end!