At least according to an algorithm:
Researchers created an algorithm to identify similar cell types from species – including fish, mice, flatworms and sponges – that have diverged for hundreds of millions of years, which could help fill in gaps in our understanding of evolution.
Cells are the building blocks of life, present in every living organism. But how similar do you think your cells are to a mouse? A fish? A worm? …
“I was struck by how stark the differences are between them,” said Tarashansky, who was lead author of the paper and is a Stanford Bio-X Interdisciplinary Fellow. “We thought that they should have similar cell types, but when we try analyzing them using standard techniques, the method doesn’t recognize them as being similar.”
Stanford University, “Bioengineers Develop Algorithm to Compare Cells Across Species – With Striking Results” at SciTechDaily
But now get this:
Tarashansky said a highlight of the research was when they were comparing stem cells between two very different flatworms.
“The fact that we did find one-to-one matches in their stem cell populations was really exciting,” he said. “I think that basically unlocked a lot of new and exciting information about how stem cells look inside a parasitic flatworm that infects hundreds of millions of people all over the world.”
Stanford University, “Bioengineers Develop Algorithm to Compare Cells Across Species – With Striking Results” at SciTechDaily
So by the time they got to flatworms, they actually saw significant similarities. Doesn’t that prompt more questions than answers?
The paper is open access.