#Evolution, #Darwin, #Mystery
The paper this video is based on can be found here: https://www.pnas.org/doi/10.1073/pnas...

Credits:
Tyler Proctor | Sound Design
https://www.tinkleinthesync.com/

Anthony Danza | Music
http://proofavenue.com/

Ashleigh Griffin | Science Advisor
https://www.biology.ox.ac.uk/people/p...

Jack Howe | Science Advisor
https://www.researchgate.net/profile/...

Jon Perry | Writing | Illustration | Animation | Voice Over
https://www.statedclearly.com/about/j...

The zygote is a single cell with half its DNA from the mother, and half from the father. Why is it that we gamble everything on a single cell each time we reproduce?

Here we dive deep into this question, learning why the single-cell bottleneck is so important in the evolution of multicellular animals, the function of genetic clonality, and we examine what is still a mysterious case of a population of animals that reproduce through fission instead of use using a single-cell bottleneck.

Note:
Many people are taking interest in the concept of sperm competition and what it does to insure the health of potential offspring. This new paper in Science does a great job diving into this complicated process: https://www.science.org/doi/full/10.1...

The title is great:
"Widespread haploid-biased gene expression enables sperm-level natural selection"

Here's another killer line from the publication:
"Genes expressed in spermatogenesis are known to experience heightened selective forces on average, but a subset of GIMs experience further increases, as evidenced by statistically significant enrichment for signatures of selective sweeps, loss-of-function intolerance, and transmission ratio distortion in humans, mice, and bulls."

As some viewers have noted, in some cases, sperm competition might select for traits good in sperm but bad in animal building. This potential problem is addressed in the paper:
"For GIMs with functions both in sperm and in somatic tissues, this could cause an evolutionary conflict for genes because optimal function in highly specialized sperm cells may be detrimental in somatic cells. We identified evolutionary pressure to avoid this conflict, because GIMs are significantly enriched for testis-specific gene expression, paralogs, and isoforms."

I should note: The conclusions of any single paper are tentative, especially a new paper like this one. Passing peer review doesn't mean the contents are "capital-T True", it simply means the peer reviewers think the argument is worth considering and the data seems legit. This is how the slow but powerful scientific process works!