Jacob Tennessen
@jacobphd.bsky.social
Scientist errant. Genetics, evolution, whimsy, awe. https://scholar.harvard.edu/jtennessen
🧬🦟🐌🩸👤🦠🍓🐸🧬
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Jacob Tennessen
@jacobphd.bsky.social
· Sep 17
Stuff I've written about biology that I think is cool (and you might too):
General musings:
adaptivediversity.wordpress.com
The Emoji Guide to Human Genetic Diversity:
scholar.harvard.edu/jtennessen/e...
More emoji-based science communication:
scholar.harvard.edu/jtennessen/b...
General musings:
adaptivediversity.wordpress.com
The Emoji Guide to Human Genetic Diversity:
scholar.harvard.edu/jtennessen/e...
More emoji-based science communication:
scholar.harvard.edu/jtennessen/b...
In complex life cycles, selection should act less efficiently in bottleneck stages. Plasmodium parasites go from a few cells at infection to 100s of millions in the blood. Selection strength varies accordingly. Brilliant work by @sarahperkins.bsky.social
royalsocietypublishing.org/doi/10.1098/...
royalsocietypublishing.org/doi/10.1098/...
Heterogeneous constraint and adaptation across the malaria parasite life cycle | Proceedings of the Royal Society B: Biological Sciences
Evolutionary forces vary across genomes, creating disparities in how traits evolve. In organisms with complex life cycles, it is unclear how intrinsic differences among discrete life stages impact evolution. Here, we look for life history-driven patterns ...
royalsocietypublishing.org
November 12, 2025 at 4:41 PM
In complex life cycles, selection should act less efficiently in bottleneck stages. Plasmodium parasites go from a few cells at infection to 100s of millions in the blood. Selection strength varies accordingly. Brilliant work by @sarahperkins.bsky.social
royalsocietypublishing.org/doi/10.1098/...
royalsocietypublishing.org/doi/10.1098/...
Polynesians had domesticated dogs, but none appear in Moana.
The Lion King showcases the biodiversity of Africa but includes no canids (jackals, painted dogs, etc.)
Does Disney practice deliberate dog erasure because people love dogs and they would steal the spotlight from the main characters?
The Lion King showcases the biodiversity of Africa but includes no canids (jackals, painted dogs, etc.)
Does Disney practice deliberate dog erasure because people love dogs and they would steal the spotlight from the main characters?
November 12, 2025 at 4:28 PM
Polynesians had domesticated dogs, but none appear in Moana.
The Lion King showcases the biodiversity of Africa but includes no canids (jackals, painted dogs, etc.)
Does Disney practice deliberate dog erasure because people love dogs and they would steal the spotlight from the main characters?
The Lion King showcases the biodiversity of Africa but includes no canids (jackals, painted dogs, etc.)
Does Disney practice deliberate dog erasure because people love dogs and they would steal the spotlight from the main characters?
You can't win, for I've already drawn you as the disheveled Putative First Animal and myself as the sleek and sophisticated Complex Early Animal.
November 11, 2025 at 5:28 PM
You can't win, for I've already drawn you as the disheveled Putative First Animal and myself as the sleek and sophisticated Complex Early Animal.
This says Anopheles mosquitoes crossed the Atlantic when it was ~2/3 of its modern width, instead of the conventionally stated Mesozoic timing when the distance was short. Is it plausible? Mosquitoes are delicate and absent from many remote islands, but life finds a way…
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...
November 6, 2025 at 11:46 PM
This says Anopheles mosquitoes crossed the Atlantic when it was ~2/3 of its modern width, instead of the conventionally stated Mesozoic timing when the distance was short. Is it plausible? Mosquitoes are delicate and absent from many remote islands, but life finds a way…
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...
Children's book idea: A grocer decides real fruits must have seeds & reorganizes the produce stands. The fruits and veggies are appalled. Zucchinis must leave their carrot friends. Bananas protest. Grape families are split up. Customers are confused. Finally the grocer learns biology isn't identity.
November 6, 2025 at 5:17 PM
Children's book idea: A grocer decides real fruits must have seeds & reorganizes the produce stands. The fruits and veggies are appalled. Zucchinis must leave their carrot friends. Bananas protest. Grape families are split up. Customers are confused. Finally the grocer learns biology isn't identity.
Only one predator species chooses its prey based on what it senses the prey has eaten. Specifically, it wants prey full of human (or other vertebrate) blood! Meet Evarcha culicivora, the spider that prefers blood-fed mosquitoes. Called the vampire spider, but this is misleading: it EATS vampires.
November 6, 2025 at 5:05 AM
Only one predator species chooses its prey based on what it senses the prey has eaten. Specifically, it wants prey full of human (or other vertebrate) blood! Meet Evarcha culicivora, the spider that prefers blood-fed mosquitoes. Called the vampire spider, but this is misleading: it EATS vampires.
Has anyone plotted the runaway inflation of PhD count per fictional character? Who has the most? Ford Pines (Gravity Falls) has 12, Mr Terrific (DC Comics) has 14, Mr Fantastic (Marvel) has 18. At this rate future media will have to give their heroes dozens of PhDs just to make the appear competent.
November 5, 2025 at 8:31 PM
Has anyone plotted the runaway inflation of PhD count per fictional character? Who has the most? Ford Pines (Gravity Falls) has 12, Mr Terrific (DC Comics) has 14, Mr Fantastic (Marvel) has 18. At this rate future media will have to give their heroes dozens of PhDs just to make the appear competent.
Right after 9/11 I lived in the Bronx and taught in Harlem. Some of my sophomores may be grandparents by now. Feeling so hopeful for them and their families as NYC rises and shines.🗽
November 5, 2025 at 2:44 AM
Right after 9/11 I lived in the Bronx and taught in Harlem. Some of my sophomores may be grandparents by now. Feeling so hopeful for them and their families as NYC rises and shines.🗽
Toxoplasma isn't "intelligent" but it manipulates the behavior of rodents & maybe other mammals. A brainless algorithm formed by natural selection to hijack brains.
AI need not know what it's doing either, but versions that engage with human psyche so as to favor their own propagation will prosper.
AI need not know what it's doing either, but versions that engage with human psyche so as to favor their own propagation will prosper.
November 3, 2025 at 3:16 PM
Toxoplasma isn't "intelligent" but it manipulates the behavior of rodents & maybe other mammals. A brainless algorithm formed by natural selection to hijack brains.
AI need not know what it's doing either, but versions that engage with human psyche so as to favor their own propagation will prosper.
AI need not know what it's doing either, but versions that engage with human psyche so as to favor their own propagation will prosper.
The government refuses to end the time change, but they have been willing to adjust what day it occurs. So let's keep pushing the fall back / spring forward days together until Standard Time is just the week between Christmas and New Year's when nobody knows what time it is anyway.
November 2, 2025 at 5:27 PM
The government refuses to end the time change, but they have been willing to adjust what day it occurs. So let's keep pushing the fall back / spring forward days together until Standard Time is just the week between Christmas and New Year's when nobody knows what time it is anyway.
An amusing subreddit to browse is /r/Birdsfacingforward
October 31, 2025 at 6:19 AM
An amusing subreddit to browse is /r/Birdsfacingforward
Parasites as Halloween characters:
Zombie = Naegleria
•Eats your brain
•Once it gets you, no cure
Vampire = Plasmodium
•Feeds on blood
•Reaches victims using flight
Werewolf = Paragonimus
•Associated with canids
•He'll rip your lungs out, Jim
Zombie = Naegleria
•Eats your brain
•Once it gets you, no cure
Vampire = Plasmodium
•Feeds on blood
•Reaches victims using flight
Werewolf = Paragonimus
•Associated with canids
•He'll rip your lungs out, Jim
October 31, 2025 at 2:59 AM
Parasites as Halloween characters:
Zombie = Naegleria
•Eats your brain
•Once it gets you, no cure
Vampire = Plasmodium
•Feeds on blood
•Reaches victims using flight
Werewolf = Paragonimus
•Associated with canids
•He'll rip your lungs out, Jim
Zombie = Naegleria
•Eats your brain
•Once it gets you, no cure
Vampire = Plasmodium
•Feeds on blood
•Reaches victims using flight
Werewolf = Paragonimus
•Associated with canids
•He'll rip your lungs out, Jim
This paper makes for great discussion.
Do I agree with their new definition of domestication? No.
Can I come up with a better one myself? Also no.
www.pnas.org/doi/10.1073/...
Do I agree with their new definition of domestication? No.
Can I come up with a better one myself? Also no.
www.pnas.org/doi/10.1073/...
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
www.pnas.org
October 30, 2025 at 3:26 PM
This paper makes for great discussion.
Do I agree with their new definition of domestication? No.
Can I come up with a better one myself? Also no.
www.pnas.org/doi/10.1073/...
Do I agree with their new definition of domestication? No.
Can I come up with a better one myself? Also no.
www.pnas.org/doi/10.1073/...
Wasting away again in Amanitaville
October 29, 2025 at 8:13 PM
Wasting away again in Amanitaville
A "monster" was originally a biological abnormality like a birth defect, believed to be an omen. But it's ableist and scientifically inaccurate to classify births as normal vs abnormal: every baby has unique mutations as well as non-genetic quirks. You are a monster, so do the mash!
October 29, 2025 at 3:28 PM
A "monster" was originally a biological abnormality like a birth defect, believed to be an omen. But it's ableist and scientifically inaccurate to classify births as normal vs abnormal: every baby has unique mutations as well as non-genetic quirks. You are a monster, so do the mash!
The move to ban Red 40 dye is comical since it's almost literally a red herring. The problems it's supposed to solve are real, and we don't need it, but ditching it won't make America any healthier. An influencer will call it a poison but a scientist will tell you that the dose makes the poison.
October 29, 2025 at 2:15 AM
The move to ban Red 40 dye is comical since it's almost literally a red herring. The problems it's supposed to solve are real, and we don't need it, but ditching it won't make America any healthier. An influencer will call it a poison but a scientist will tell you that the dose makes the poison.
If you don't have bread to go with your curry, you can use tortillas instead. It's a naan-synonymous substitution.
October 28, 2025 at 10:33 PM
If you don't have bread to go with your curry, you can use tortillas instead. It's a naan-synonymous substitution.
The presumptive next Surgeon General laid out her vision last year. Public health is in for a wild ride. She comes close to getting it and identifies a lot of real problems, but she sees science as a fundamentally corrupt system and endorses wacky nonsense instead.
www.caseymeans.com/learn/newsle...
www.caseymeans.com/learn/newsle...
Newsletter #35: 🇺🇸 My health wishlist for the next Administration — Casey Means MD
More than anything, I would like to see our future White House rally Americans to be healthy and fit. We need inspirational national leaders helping to inspire people to care about their health, the f...
www.caseymeans.com
October 28, 2025 at 3:45 PM
The presumptive next Surgeon General laid out her vision last year. Public health is in for a wild ride. She comes close to getting it and identifies a lot of real problems, but she sees science as a fundamentally corrupt system and endorses wacky nonsense instead.
www.caseymeans.com/learn/newsle...
www.caseymeans.com/learn/newsle...
By convention we name science projects after scientists. If someone says they've read Tennessen (2008) you wouldn't say "well actually Tennessen was the doctor, not that monster of a paper." The doctor and the monster have the same name.
October 27, 2025 at 2:06 PM
By convention we name science projects after scientists. If someone says they've read Tennessen (2008) you wouldn't say "well actually Tennessen was the doctor, not that monster of a paper." The doctor and the monster have the same name.
Fuegian “dogs" were not dogs but a partially domesticated form of the fox-like Patagonian culpeo, bred by the Selk’nam people for aid in hunting. A genocide c. 1900 targeted these pets and drove them extinct, though the Selk’nam survived.
Human ingenuity, and human cruelty, shape genetic diversity.
Human ingenuity, and human cruelty, shape genetic diversity.
October 26, 2025 at 6:38 PM
Fuegian “dogs" were not dogs but a partially domesticated form of the fox-like Patagonian culpeo, bred by the Selk’nam people for aid in hunting. A genocide c. 1900 targeted these pets and drove them extinct, though the Selk’nam survived.
Human ingenuity, and human cruelty, shape genetic diversity.
Human ingenuity, and human cruelty, shape genetic diversity.
It didn’t evolve in subway tunnels, but this is still a story of a new species of urban-adapted mosquito created accidentally by humans, the kind of thing we probably want to avoid doing.
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Ancient origin of an urban underground mosquito
Understanding how life is adapting to urban environments represents an important challenge in evolutionary biology. In this work, we investigate a widely cited example of urban adaptation, Culex pipie...
www.science.org
October 25, 2025 at 8:12 PM
It didn’t evolve in subway tunnels, but this is still a story of a new species of urban-adapted mosquito created accidentally by humans, the kind of thing we probably want to avoid doing.
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Back in middle school, some friends and I started a club called Kids Protecting Our Planet, or KPOP. We never hunted demons though.
October 24, 2025 at 11:05 PM
Back in middle school, some friends and I started a club called Kids Protecting Our Planet, or KPOP. We never hunted demons though.
Bivalve making a toast: Pseudofeces for my real friends, and…
October 24, 2025 at 5:09 AM
Bivalve making a toast: Pseudofeces for my real friends, and…
With two big recent tomes on TB (Everything is TB; The Phantom Plague) I await a pop sci book on schisto. Affecting >200 million people; lots of not-for-the-squeamish symptoms like diarrhea, blood in stool/urine, anemia, swollen potbelly, etc.; and spread by sewage-dwelling snails! Super compelling!
October 23, 2025 at 10:48 PM
With two big recent tomes on TB (Everything is TB; The Phantom Plague) I await a pop sci book on schisto. Affecting >200 million people; lots of not-for-the-squeamish symptoms like diarrhea, blood in stool/urine, anemia, swollen potbelly, etc.; and spread by sewage-dwelling snails! Super compelling!
For a great satire of American gun culture, see the first chapter of From the Earth to the Moon written in 1865. I guess we've always been like this.
October 22, 2025 at 1:02 AM
For a great satire of American gun culture, see the first chapter of From the Earth to the Moon written in 1865. I guess we've always been like this.