---
title: Evolution of Humans
disqus: hackmd
---
:::success
> Documentation [name=MrDr.Staffan]
##1a #q~#### tags: `Evolution`

### Table of Contents
[TOC]
:::
[3Top](#Table-of-Contents)

==[Lemurs lost noses, gained Eccrine?]==
==[Water ape]==
==[Fur]==


Pleistocene
Holocene


# Animals shaking off trauma
[Or hunt? We are small hunter Tracking patterns, visual tracking. Endurance as one, but not the only tactic.]
Acetyl-choline

[Build-up of unreleased acetylcholine in pre-synaptic Neurons.

Anxiety. A fast cholinergic system.

Stress that doesn't get release overscales these terminals. Leading to propensity for anxiety/buildup of acetylcholine?]

# Milestones EvoluTion of human

https://www.visualcapitalist.com/path-of-human-evolution/

CynogNathus - when third eye was lost. Pineal gland.

# 330 Ma

## Keratin Eggs
## Cranial nerves
## Adrenal glands

#loss of gills

# 300 Ma

## Diaphragm
## Mouth 2nd palate

#Loss of scales

# 260 Ma

Warm blood
Adv. Lymphatic system

Thick skin.

Third eye internalized. Pineal gland

[The mammalian pineal gland: known facts, unknown facets](https://www.cell.com/trends/endocrinology-metabolism/fulltext/S1043-2760(07)00032-X#fig3)

# 230 Ma
## Nocturnal
pineal gland?

## Milk and sweat glands

## Fur
Fur first appears

## Constant body temperature
"Constant"

# 170 Ma

## Live eggless births

Marsupial pouches
Nipples
Placenta
Genitals

# **65-54.8 Ma Paleocene**

## 67 Ma psilocybin
https://www.pnas.org/doi/10.1073/pnas.2311245121

## 65 Ma forward facing eyes
And grasping

## 65 Ma Uricase and Uric acid
The loss of uricase in higher primates parallels the similar loss of the ability to synthesize ascorbic acid, leading to the suggestion that urate may partially substitute for ascorbate in such species.[14] Both uric acid and ascorbic acid are strong reducing agents (electron donors) and potent antioxidants. In humans, over half the antioxidant capacity of blood plasma comes from hydrogen urate ion.[15]

**[[When humans lost Uox. We These are the neuronal cell types that got a boost in reductive capacity? due to having had highest ability to breakdown Uric acid to urea ]]**
metabolic breakdown of purine nucleotides. This could mean they became less able?

Uox is in mice, very high in Ependymal cells

PSNP6 Non-peptidergic (NP3), DRG **0.0903**

TEGLU10 Excitatory neurons, cerebral cortex 0.0344
MEGLU14 Glutamatergic projection neurons of the raphe nucleus 0.0211
TEGLU5 Excitatory neurons, cerebral cortex 0.0158

DEINH4 Inhibitory neurons, thalamus 0.0175

HBCHO3 Afferent nuclei of cranial nerves VI-XII 0.0277
ENT8 Cholinergic enteric neurons, VGLUT2 0.0307
SYCHO2 Cholinergic neurons, sympathetic 0.0264

HBSER3 Serotonergic neurons, hindbrain 0.0228
HBSER5 Serotonergic neurons, hindbrain 0.0155
HBSER4 Serotonergic neurons, hindbrain 0.0277

ENT1 Nitrergic enteric neurons **0.0710**

HYPEP5 Vasopressin-producing cells, hypothalamus 0.0172
HYPEP4 Oxytocin-producing cells, hypothalamus 0.0102

EPEN Ependymal cells **0.380**
EPSC Ependymal cells, spinal cord **0.134**
EPMB Ependymal cells, midbrain 0.0144

Variants of a number of genes, linked to serum urate, have so far been identified:
**SLC2A9**;
PDZK1.[25][26][27] GLUT9, encoded by the SLC2A9 gene, is known to transport both uric acid and fructose.[18][28][29]
**ABCG2** ([Ncult](https://docs.google.com/spreadsheets/d/1ExKN0yQ0-Cv7HjRLVrnQza-T9s0_j9_Pf92G7IDfzx8/edit#gid=741940387&range=A183));
**SLC17A1**;
**SLC22A11**; [Only in Hs](https://docs.google.com/spreadsheets/d/1ExKN0yQ0-Cv7HjRLVrnQza-T9s0_j9_Pf92G7IDfzx8/edit#gid=1009969694&range=A146) Uric acid, Inhibited by Octanoic acid?
**SLC22A12**;
**SLC16A9**;
GCKR;
**LRRC16A**; ([A+O](https://docs.google.com/spreadsheets/d/1ExKN0yQ0-Cv7HjRLVrnQza-T9s0_j9_Pf92G7IDfzx8/edit#gid=112430370&range=A3920)) Optic nerve

### Uox
Peroxisomes are cellular organelles present in virtually all eukaryotic cells. UOX is synthesized on free ribosomes in the cytoplasm and imported into peroxisomes post-translationally with the action of a translocation signal (PTS1) at the C-terminal. In mammals, urate oxidase is mainly localized to liver peroxisomes, forming crystal cores [18,19].

## 65 Ma Vitamin C
[See Vitamin C](https://hackmd.io/@sholmqvist/BJpKurTBB/%2FVRxXizYGTSmR_hDbuSI8LQ#Vitamin-C)

**[[Before humans lost Uox and Gulo. We These are the neuronal cell types that needed most reduction?]]**

Gulo
L-gulono-γ-lactone oxidase

Cells with highest Gulo transcripts
**HBCHO3** Afferent nuclei of cranial nerves VI-XII
*Markers: Slc5a7 Tbx20 Adcyap1 AW551984 Tmem26"
High:
Slc18a3 Vesicular (acetyl)+choline transporter
SLC5A7 Choline

[](https://mouse.brain-map.org/experiment/siv?id=69874012&imageId=69826511&initImage=ish&coordSystem=pixel&x=6776&y=3752&z=2)

[](https://mouse.brain-map.org/experiment/show?id=79762433)

then

**HBINH1** Inhibitory neurons, hindbrain
Pons, interpeduncular and tegmental nuclei in rh1
*Markers:* Chrna2 Nos1

**ENT6** Cholinergic enteric neurons

Gulonic acid


Gulonolactone

The classic example of a unitary pseudogene is the gene that presumably coded the enzyme L-gulono-γ-lactone oxidase (GULO) in primates.


## Evolution of vitamin C Pathways
https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-022-02040-7

[Here the interesting question is not how do we get vitamin C. Or what happens when we don't. The real question is, what happens to the rest of the system when we don'T?
-Or- where does all the gulonic acid go?]

# **54.8 - 33.7 Ma Eocene**

## 50 Ma menstruation cycles
~50Mya

## MenoPaus.
Only six species – humans and five types of toothed whale – are known to experience menopause

[How would you explain the "function" loss of another function has with gradual evolution.?"]

The latest work suggest experienced female mothers also help their sons navigate social relationship

[i.e once they are not longer having that behaviour to the same degree imprinted, as they become "masculanized" they can help their sons, but not their daughters. Likely 'helping' daughters May be built into them being female. ]

since its a matriarchy, this could be the effect of having a senior leader around. How do they know that the bite marks are from after another animals menopause?

## 50 Ma single pair of nipples
~50Mya

The loss of nipples may signify a selective pressure to nurse few offspring extensively rather than as many as possible.

# **33.7-24 Ma Oligoscene**

## 34 Ma
Paratethys (caspian sea) formed about 34 Ma (million years ago) at the beginning of the Oligocene epoch,[3]

# **24-5 Ma Miocene // Neogene**

## 14 Ma Nacholapithecus kerioi
Nacholapithecus kerioi was an ape that lived 14-15 million years ago[1] during the Middle Miocene.

## 11.6 Ma Boronius
late Miocene Epoch, 11.6 million years ago. The new genus is called Buronius manfredschmidi.

## 11-5 Ma Chimp last common ancestor
The chimpanzee–human last common ancestor (CHLCA)

# **5 Ma - 10K Pleistiocene**

# Lucy
Lucy was a member of the species Australopithecus afarensis, an extinct hominin – a group that includes humans and our fossil relatives. Australopithecus afarensis lived from 3.8 million years ago to 2.9 million years ago, in the region that is now Ethiopia, Kenya and Tanzania. Dated to 3.2 million years ago, Lucy was the oldest and most complete human ancestor ever found at the time of her discovery.

Lucy stood on two feet and had a small brain, not much larger than that of a chimpanzee

Lucy proved unequivocally that standing and walking upright was the first step in becoming human. In fact, large brains did not show up in our lineage until well over 1 million years after Lucy lived.


# Lungs and fire

[The Exposome in Human Evolution: From Dust to Diesel](https://www.journals.uchicago.edu/doi/full/10.1086/706768)


ApoE

## 500K - Fire
Fire? Ref.

## Denisovians
Shown not by fossils but also dna

285 to 25 thousand years

## 30K - Light skin color.

My own research provided some of these findings, showing that positive selection in the ancestors of today's European and East Asian populations had affected many genes, including some involved in pigmentation. Those changes were mostly after 30,000 years ago, after the Neandertals were gone

woven linen fabrics from wild flax may date back over 30,000 years.[3

# **10K-Now Holocene**

# smoke and fire
The brain that lost its sense of smell. (compared to previous Apes/humans).

That the loss of a sense enables a great flexibility in brain plasticity. If large part of the brain does not have to focus on previous Smell related estimations. It can Instead adopt other parts.

How blind people can use their visual cortex for oTher tasks.(ref?).

Or how people with half a brain adapts.

# Meat eating non-human primates
[Meat eating by nonhuman primates: A review and synthesis](https://www.sciencedirect.com/science/article/pii/S0047248420301433)

[Loving bonobos have a carnivorous dark side](https://www.newscientist.com/article/dn14926-loving-bonobos-have-a-carnivorous-dark-side/)

# Symbols and language.
Sharing our internal world.

If this is unique to humans, it implies that humans are particularily good at introducing our inner world into the external (shared world) this in a real sense makes us share internal world (models).

What other animals can communicate their internal world?
Many, any animal that can display their emotions is in effect sharing their internal world.

**Emotions**.
Emotions as such is the result of signals / patterns we are unable to priocess in a controlled way. These are then sent to the DI to be reintegrated in what is seemingly a sweeping way.

Brain activity becomes the job of filtering patterns of impressions in order to choose an appropriate response.

If there is no specific (pre-trained) response the "information" // the impression is reinjected into the DI but this time has no clear source. These inputs are therfore unprecise and hence seem to come from inside us.

This new "sourceless // sense independent" input to DI will then be difficult to handle and thus more likely to process into a specfic action.

That is why fear is the mind killer. As fear, that is not routed functionally / integrate it // processes it, only makes it end up unprocessed and reinjected into the DI thereby rinforcing it.

Yet some form of integration will always happen as it passes through the network. This way repeated difficult to process information eventually becomes meaningless.

Hence CBT

This theory has similarities (but was not actively thought about as the psychological Triangel. Ie. action leads to emotion leads to thoughts lead to emotions, leads to action.)

It also shows why this process is only needed, when there is a failure of integration.

This predicts that cortical(amygdala)-DI connections would diminish in the amygdala-DI signaling (as the signal is "purposfully/frictionlessly" diverted to some action).

This also highlights the difference between "information" in a computer and that in living systems. In a computer a signal is meaningless if it doesnt lead to something. in living systems where signals arre not pure electrons patterns - signals/information is carried by bona fide matter. that is in part electrons, but also single atoms (ions), molecules, proteins etc.

The main difference is that in acomputer a signal that doesnt lead anywhere ends there, creates heat?.

While in a living system, this information is carried in molecules that have to go somewhere and be handled.
Hence the higher level of complexity that the living information system takes place in comes with certain inherent consequencs. And what is waste to one system is instructions for the next. looking at each of these systems separately will not be logically intelligable. However togheter they form purpose full mechanisms in the organism as a whole. JUST LIKE AN ECOSYSTEM.

# human nest building

Consequences?
Did we always put most of our 'money' on housing. Are we nomads?

Does being outside, and then going inside. Have impact on their interaction with the world.?
Artificial darkness.

## Living underground.
Also see n-mole rats

# Human chin
modern humans (Homo sapiens) are the only species with a chin, an anatomical feature with no known function
Even Neanderthal jaws ended in a flat vertical plane

# Fur
[See Water ape hypothesis](https://hackmd.io/@sholmqvist/BJpKurTBB/%2F_nRvA-YUSomXntMLaaOJsw#Water-ape-hypothesis)

[See Neoteny](https://hackmd.io/@sholmqvist/BJpKurTBB/%2F_nRvA-YUSomXntMLaaOJsw#Neoteny)

[did we turn our entire bodies into morrhår. Men sen tappade morrhåren? See below]

Human babies are without hair.

Humpback whales "barnacle-like" bumps on their head are golfball sized hair folicles.

The group of baleen (Bard-) whales has very small hair-like whiskers on their muzzle, chin and jaw line

Dolphins are whales with teeth.
Some dolphins have hair in the womb as fetuses and lose it before they are born whereas other dolphins are born with hair and lose it soon after birth. (sparse hair or whiskers usually on snout)

Harp Seals: These babies are born covered in thick white fur

Sea Otters: They look like beavers but are much, much bigger! Sea otters can get to be 4 feet long and weigh around 90lbs. They spend most of their time in the water, searching for food and floating on their backs in groups called “rafts”. They have the thickest fur of all animals with over 900 million hairs.

# Loss of morrhår.
We humans lost the DNA for whiskers around 800,000 years ago as other parts of our bodies became more sensitive, such as our fingers.

[Whiskers are vibrissae, keratin filaments that grow out of different follicles than hair. Whisker follicles are much deeper than hair follicles and are surrounded by pockets of blood that amplify vibrations to better communicate information to the nerve cells beside the follicles](https://www.mcgill.ca/oss/article/did-you-know-history/whiskers-humans)

You may have noticed when looking at your cat that there are 2 kinds of whiskers, long and short.

Long whiskers are macrovibrissae and can be moved voluntarily.

Animals use these to sweep areas (called whisking) to navigate spaces and generally feel the world.

Short whiskers are microvibrissae, and they cannot be moved voluntarily. These are used specifically for object recognition, whether it’s your rat’s favourite toy or your hand.

The human brain devotes *relatively huge* [funny way to put it] portions of itself to sensing and processing touch.

[Also double as heat sinks?] Do only mammals have whiskers?

a type of stiff, functional hair **used by mammals** to sense their environment

## Evolution of whiskers vibrissae

Nearly all mammals have whiskers – sensory tactile hairs, also known as vibrissae (Fig. 1). They are only truly absent in a handful of species, including humans.

The last universal common ancestor of all extant mammals had vibrissae.[5]

[28.9 Great apes lack Whiskers]
Great apes are the only extant mammal species which do not have vibrissae. All extant mammal species retain the ancestral layout of the whiskers along with the special facial muscles that move them.[3]

## Whiskers and piloerection?
The formation of goose bumps in humans under stress is considered to be a **vestigial reflex**.[3]

A vestigial response or vestigial reflex in a species is a response that has lost its original function. In humans, vestigial responses include ear perking, goose bumps and the hypnic jerk.

## Control and effects of piloerection

[The most credible function of piloerection is to increase fur thickness and thereby the amount of trapped air. Reducing the need to provide energy from temperature in cold.]
[Earlier mammals might have used it to "look big", albeit this suggestion seems incredible.]

The reflex is started by the sympathetic nervous system, which is responsible for many fight-or-flight responses.

Arrector pili muscles (APM) are smooth muscles
In between the hair follicle and the APM there are lobules which form an angular shape. These lobules are sebaceous gland lobules which are supported by the APM.[6] [Thereby the contraction of the muscle and piloerection is anatomically coupled to squeezing of sebaceous gland lobules]
secrete sebum. Sebum is a substance that provides a protective coating for your skin to help it retain moisture.

Voluntary control
An unknown proportion of people may consciously initiate the sensation and physiological signs of piloerection. The phenomenon is discovered spontaneously, appearing to be innate, and is not known to be possible to learn or acquire. Those with the ability frequently are unaware that it is not possible for everyone. The ability appears to correlate with personality traits associated with openness to experience.[23]

## Sebum

secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals.[2] wiki

sebaceous glands occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet.

composed of triglycerides (≈41%), wax esters (≈26%), squalene (≈12%), and free fatty acids (≈16%).[7][14] Wiki

Wax esters and squalene are unique to sebum and not produced as final products anywhere else in the body.[5] [Really? isnt squalene an intermediate to cholesterol? It perhaps the only gland medicine knows that produces it for a specific function.]

**Sapienic acid** is a sebum fatty acid that is **unique to humans**, and is implicated in the **development of acne**.[15] Sebum is odorless, but its breakdown by bacteria can produce strong odors.[16]

[See FA sheet Sapienic acid](https://docs.google.com/spreadsheets/d/1m2mHV2WSeV8XSYT9GT5xUU0FTjzT41Dw8M_lFFnn8Wo/edit#gid=1734563512&range=B93)

C 16:1ω10 // 16:1delta6

Delta-6-desaturation of palmitic acid leads to the biosynthesis of sapienic acid

[Is there a peak in UFA in adolescence]

In other tissues linoleic acid (18:2 cis-9,12.) is the target for delta 6 desaturase, but linoleic acid is degraded in sebaceous cells, allowing the enzyme to desaturate palmitic to sapienic acid.[6][7]

delta-6 desaturase // FADS2
[FADS2 is also expressed in mouse & human glia.]

Sapienic acid can lead to the decanal which is likely what mosquitoes use to identify human prey.[8]

## Sebum consitute fatty acids
The fatty acids of waxes isolated from the preputial gland are present in the following order of abundance: C16:1 > C18:1 > C16:0 > C20:0 > C14:0, and the fatty alcohol moiety is predominantly C16:0 (18). Each of these fatty acids or alcohols is utilized as a substrate by the mouse enzyme in vitro (Fig. 3, A and B) and presumably in vivo as well. Despite this correlation, additional factors must influence the wax composition of sebum, including the substrate preferences of the fatty acyl-CoA reductases, intracellular lipid transport proteins, and fatty acid synthesis enzymes. These inputs may explain the absence of short chain fatty acids (e.g. C10:0 and C12:0) from sebum waxes even though these lipids are excellent substrates for the wax synthase in vitro. ([2004](https://www.sciencedirect.com/science/article/pii/S0021925820730528?via%3Dihub))

**Adult human sebum** is composed principally of wax monoesters (25% of total lipids), triglycerides (41%), free fatty acids (16%), and squalene (12%),

**Mouse fur sebum** is wax monoesters (5%), wax diesters (65%), triglycerides (6%), and free and esterified sterols (23%). Within the mouse, the sebum elaborated by the preputial glands, which are specialized sebaceous glands involved in pheromone production, has a much higher content of wax monoesters (48%) than fur sebum (1).

[[Connection to loosing certain sense of smell? & water-ape?]]

## Sapienic acid & Mitochondrial / peroxisomal dynamics
[See Outline slides](https://docs.google.com/presentation/d/1V1G5JW11ihcb9ICCSz0xNwYFXyv0fXw2cM0lUgUrkJ0/edit#slide=id.g4fa6360217d1ad8c_35)

[See Predictions](https://docs.google.com/document/d/1qK9vX7etgtTp40jZRC6rSGAhIeTOsUsQMBVuTwDeoGc/edit)

C16:1w10. In practice this implies that after 2 (or 3) rounds of acetyl shortening. They have to leave the Mitochondria to be handled in peroxisome. In neurons this export means they end up toward ER? the form ought to be in the range C10, C11, C12,C13,C14?

[[This range is interesting.
- SFA shorter than C9 become less soluble when attached to CoA i.e. they are not likely be associated with CoA
- SFA longer than C17 CoA-conjugation still makes them less soluble than 1mM
]]
[See FA sheet](https://docs.google.com/spreadsheets/d/1m2mHV2WSeV8XSYT9GT5xUU0FTjzT41Dw8M_lFFnn8Wo/edit#gid=1734563512&range=I107)

[[Yet, There is no clear reason why those below 1mM solubility would be less interesting??]]

Meaning that Neurons that are fed UFA, will use some of them in mitochondrial b-ox. but then they cant be shortened more.

This suggests that UFA does not contribute anaplerotically to the neuronal TCA, instead are directed as MCFA to the ER/Synapse to form SV???

Possibly neurons lack ability to introduce b-hydroxy to activate the first step of fuel utilization.

B-hydroxylated UFA?

20240531
C16:1ω7
Palmitoleic acid

C16:1ω10
Sapienic acid

Very difficult to study beside direct action As Double bond placement is not readily observable for lipidomics.

[[Big data and bulk analysis will become increasingly automated]]

The questions that escape these methods will be lower-hanging.]]

---
If this is the case, then the desaturases with a specific target d5 d4 etc. n7 n9.

[[How does the FA fit into the pocket of the desaturase?]]

1. Are in effect determining how many acetyl-groups can be cut off from the particular FA (unless it also gets extended)

2. How long the remaining "tail-end" is as it gets exported from the mitochondria. In neurons this is critical as they are not simply handled by the peroxisome.

Instead they are directed toward the ER and SVs?

# Sweat glands Eccrine
Apocrine - armpits. Not significant for cooling.

Sweat glands are appendages of the integument. There are eccrine and apocrine sweat glands. They differ in embryology, distribution, and function. Eccrine sweat glands are simple, coiled, tubular glands present throughout the body, most numerously on the soles of the feet.


**Eccrine sweat** glands are distributed almost all over the human body, in varying densities, with the highest density in palms and soles, then on the head, but much less on the trunk and the extremities. Its water-based secretion represents a primary form of cooling in humans

**Apocrine** sweat glands are mostly limited to the axillae (armpits) and perineal area in humans.[8] They are not significant for cooling in humans, but are the sole effective sweat glands in hoofed animals, such as the camels, donkeys, horses, and cattle.

**Ceruminous** glands (which produce ear wax)

**Mammary** glands (which produce milk

**Ciliary** glands in the eyelids are modified apocrine sweat glands.[2][12

<br><br><br><br>
# why eccrine glands?

"Eccrine glands start to form during the fourth to fifth month of gestation: first on the palms of the hands and soles of the feet. Eventually, they cover almost the entire body, but they're not all completely active when a baby is born. When they’re newborns, the most active eccrine sweat glands are on their forehead, which is why parents often say their newborn's forehead feels sweaty.”

## Eccrine - Watery
They are ten times smaller than apocrine sweat glands

Non-primate mammals have eccrine sweat glands only on the palms and soles.

[Humans have a uniquely high density of sweat glands embedded in their skin—10 times the density of chimpanzees and macaques.](https://www.pennmedicine.org/news/news-releases/2021/april/the-chillest-ape-how-humans-evolved-a-super-high-cooling-capacity)

Apocrine glands cover the rest of the body, though they are not as effective as humans' in temperature regulation (with the exception of horses')

[The Chillest Ape: How Humans Evolved A Super-High Cooling Capacity "Engrailed 1 // Eng1"](https://www.pennmedicine.org/news/news-releases/2021/april/the-chillest-ape-how-humans-evolved-a-super-high-cooling-capacity)

==[Lemurs lost noses, gained Eccrine?]==

Engrailed 1—EN1 in humans—helps determine the density of eccrine glands in mice.

Cholinergic- rather than adrenergic-induced sweating play a role in developing and developed rat eccrine sweat glands
Exp Anim. 2021
adrenergic

### ENG1
EN1 encodes a transcription factor protein that, among many other functions, works during development to induce immature skin cells to form eccrine glands

"The Chillest Ape: How Humans Evolved A Super-High Cooling Capacity"

This is not normal. This is the full expulsion of energy. A full-on enzyme?

[Could we in theory measure how important systems are in converting energy? How close they are to mass-conversion? That ]

## Apocrine

## uncombable mammoths

https://www.cell.com/current-biology/fulltext/S0960-9822(23)00404-9

Adgrv1

## Water ape hypothesis
As mentioned by Agnes Wold.

The idea that early humans were coast dwelling monkeys and we almost like the whale species (? Canacea) Went back to the ocean.I am living on the east African beach. Thereby we adopted to eating seafood (rich in Putrescine (?) and UFA).

According to h:
also when we lost our fur.
Also why babies can swim. not likely, more likely they are used to not breathing. Seals have fur.

[Hypothesis: i think the naked mole human is a better hypothesis - neoteny]

[however the poor human night vision would rather support a beach than an underground lair.] [therefore possibly a life at the beach, giving so much resources that neoteny can occur.] spare energy is the driver of extended youth longer life length by extending youth - delaying development. Make more of the population vulnerable. The costI am absorbance of parental energy into the kids iS bound in the young but released over time as they live longer. (pref. Being young adults longer.) the "extra" care provided by the parents

Explains why we find younger attractive (only true in men?)

Also explains individual extrems such as pedofiles.

[btw, I do matriarchal societies prefer younger men?]

[Interpret/addon Fish and to less degree birds should be a major route of nutrient differentiation from the colder polar regions towards the equator and subsequently onto land.]

# skin pigmentation
OCA2

https://johnhawks.net/weblog/what-color-were-neandertals/amp/
<br>
# Hands & feet

## Proportions & general
https://www.nature.com/articles/ncomms8717

The dexterous fingers of squirrel monkeys are not only great for gripping onto branches, but also come in very useful when opening fruits and holding onto prey.

Scientists have captured a video of an **aye-aye**, a kind of primate, picking its nose in a rather gruesome fashion.

## Human nails instead of claws

[Humans have peculiar fingers, what and when did this change? As we became upright? before? after?

So, why did the ancestors of monkeys, apes and humans lose their grooming claws? One possible answer: because we have each other. “The loss of grooming claws is probably a reflection of more complex social networks and increased social grooming,” Boyer said.

Grooming/toilet-claws.

"“The loss of grooming claws is probably a reflection of more complex social networks and increased social grooming,” Boyer said. “You’re less reliant on yourself.”

This could explain why more solitary monkey species, such as titi and owl monkeys, have re-evolved a grooming claw, he said."

https://www.floridamuseum.ufl.edu/science/ancient-primates-had-grooming-claws/#:~:text=So%2C%20why%20did%20the%20ancestors,social%20grooming%2C%E2%80%9D%20Boyer%20said.

The first toe is the large one, the equivalent of a human big toe. However, in all these prosimians the foot is more or less hand-like. The first toe is opposable, like a human thumb, and the second and third toes correspond approximately to the index and middle fingers.

Like a claw or a nail, the grooming claw is also made of keratin. It resembles a claw in both its lateral compression and longitudinal curvature. However, the tip is not as pointed, and it always stands at a steeper angle, a characteristic that also distinguishes it from a nail.[1
## Opposible thumbs
Primate common ancestor got opposable thumbs (see below).

# Hearing and ears.
[](https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.a.20117#:~:text=Low%2Dfrequency%20hearing%20limits%20range,kHz%20for%20the%20lesser%20bushbaby.)
[Note the exceptionally poor hearing of humans.]


[](https://www.utoledo.edu/al/psychology/pdfs/comphearaudio/primate_hearing_from_a_mammalian_perspective.pdf)
https://www.utoledo.edu/al/psychology/pdfs/comphearaudio/primate_hearing_from_a_mammalian_perspective.pdf

[Humans and elephants have "slow hearing", These should be corrected for size, or skull thickness or similar]

The internal auditory meatus provides a passage through which the vestibulocochlear nerve (CN VIII), the facial nerve (CN VII), and the labyrinthine artery (an internal auditory branch of the anterior inferior cerebellar artery in 85% of people) can pass from inside the skull to structures of the inner ear and face. It also contains the vestibular ganglion. - wiki

## Specifc animal ranges
hiddenhearing.co.uk/hearing-blog/hearing-loss/what-animals-have-better-hearing-than-humans
poor reference

**Humans 20 Hz up to about 20 kHz**

(Sounds above 8 kHz are considered as extended high frequencies (EHF) and are often ignored by researchers, although others suggest that these frequencies can give our hearing a boost, especially when trying to listen to speech in noisy environments.)

**Dog** is dependent on its breed and age. However, the range of hearing is approximately **40 Hz to 60 kHz**. (german shepards and miniature poodles, are more susceptible than other breeds to age-related hearingloss.)

**Bats** need sensitive hearing to compensate for their lack of visual stimuli, particularly for navigation when hunting. Their hearing range is between **9 kHz and 120 kHz**.

**Mice** have large ears in comparison to their bodies. Mice hear higher frequencies than humans; their frequency range is 1 kHz to 70–90 kHz. They do not hear the lower frequencies that we can; they communicate using high frequency noises some of which are inaudible by humans. The distress call of a young mouse is about 40 kHz, twice as high as we can hear.

**Moths up to 300 kHz**, 15 times higher than humans. Possibly this high range is an adaptation to predation by bats.

**Elephants 16 Hz–12 kHz**, an elephant will use its ears to help them keep cool.

**Cats 45Hz – 64,000Hz**, but their ears are also mechanically remarkable. A human ear consists of three muscles and the three smallest bones in the body; a cat’s ears are controlled by around three dozen muscles per ear which allows them to rotate their ears 180 degrees

# Neoteny

# Other things. Related?

[Is human experience "contained". That is do we [an old käpphäst] have a brain that has certain outputs. And all we can do is shift the focus of this output/function. Is the sum of all suffering constant? Is the sum of all worry constant? Is the sum of all love constant. "we have a part, and it does it job". If you solve one emotional trigger, does another one step in to stimulate the network leading to the experience?]

[ I think my way of thinking is the same that AI will result in when it comes to biology. Which is tracing the general picture, rather than the specific. This is how I work (i think) by summing up widely different sources of information, integrating them and drawing conclusions on the overall pattern.]

This a) means AI is challenging my type of intelligence. b) that that type of intelligence is going to advance, and I have a head start.

Practically, this means I only assume patterns that are presented in different datasets. "that have a logic to them, regardless of which data you use to conclude it. Verified by different sources"

[Perhaps it would make sense to do every experimental angle of investigation for each thing you want to establish. Rather than "proving" your idea based on your (research groups) experiments, separated from all others. Published/concluded on their own merit? rather than doing a few and then fitting the conclusions into ]]
]

<br><br><br><br>
# Organs and functions lost or impaired in humans

## Olfaction
See Olfaction. "not worse, different

##

Noses of Nasalis larvatus
Look very odd both compared to other animals and to the noses oh humans. I however, these monkies children's noses look surprisingly like out own.


## Vomeronasal organ (VNO)

## Rhinarium

### An Early mammalian trait.
glandular rhinarium is similar to Philtrum (the FAS slit) and slit-like nostrils, common to therian mammals

**Philtrum** Flat lip can also suggest Prader–Willi syndrome.

**Philtrum** , Similar to Rhinarium.
https://en.wikipedia.org/wiki/Philtrum

A study of boys diagnosed with **autism spectrum** disorders found that a broader than average philtrum is one of a cluster of physical attributes associated with autism.

medial cleft, is a vertical indentation in the middle area of the upper lip, common to therian mammals, extending in humans from the nasal septum to the tubercle of the upper lip.

In humans, the philtrum is formed where the nasomedial and maxillary processes meet during embryonic development. When these processes fail to fuse fully, a cleft lip may result.

### **General**
The rhinarium is adapted for different purposes in different mammals, according to ecological niche

In aquatic mammals, the development of lobes beside the nostrils allows them to close for diving.

In elephants, the rhinarium has become a tactile organ

The rhinarium is a separate sense organ: it is a touch-based chemosensory organ that connects with a well-developed vomeronasal organ (VNO).

VNO

In mammals that dig or root with their noses, the rhinarium often develops into a resilient pad, with the nostrils off to the side (or below) and capable of closing to keep out dust. Examples include the common wombat, marsupial mole, and members of the Chrysochloridae


lack of an obvious rhinarium in Tarsiiformes has been interpreted by some scholars as the consequence of the enormous development of the eyeballs, rather than a loss of relevance of olfaction,[10] but the significance is currently debatable, because there currently is an influential body of opinion favouring inclusion of the tarsiers in the Haplorhini rather than in the Strepsirrhini as had been traditional.[11]

The rhinarium is used to touch a scent-marked object containing pheromones (usually large, non-volatile molecules), and transfer these pheromone molecules down the philtrum to the VNO via the nasopalatine ducts that travel through the incisive foramen of the hard palate

It also acts as a wind-direction detector: cold receptors in the skin of the rhinarium detect the orientation where evaporative cooling is highest, as determined by the wind direction.
[The ability to detect
wind direction].

The study of the rhinarium's structure and associated functions has proven of considerable importance in the fields of mammalian evolution and taxonomy.[5]

For example, primates are phylogenetically divided into those, such as lemurs, with the primitive rhinarium (Strepsirrhini) and the dry-nosed primates (Haplorhini, including apes and humans).

[Dvs, korrelerar det här med Mönnsklig hud? ]
The rhinarium is described as **wet in most species** but eccrine glands in rhinarium skin have been described only in a handful of species.

### Lacking Rhinarum - Dry nosed
Rhinarium is lost by Tarsiiformes amd Lemurs.

Strepsirrhini ("moist-nosed"
Haplorhini "dry-nosed" primates

<br><br><br><br>
# picking nose
The aye-aye is the newest member of an exclusive club: animals that pick their nose


https://www.nhm.ac.uk/discover/news/2022/october/aye-aye-recorded-picking-nose-eating-snot-first-time.html

For example, a survey of 254 Americans in the 1990s found that 91% of respondents said they picked their nose, with three quarters professing the belief that 'almost everyone does it.'

"Some scientists believe that the microbes trapped within it could help maintain the resilience of our immune system. Meanwhile, another study suggests compounds in nasal mucus can reduce the ability of cavity-causing bacteria to attach to teeth, potentially contributing to our oral health."

[i.e. Instinctive trait to touch and smell the world. Intentionally exposing our self by sampling the world. This way our body can become more resilient.]

this predicts that people who strictly stop their kids from picking their noses, might have more immunologiclly sensitive.

<br><br><br><br>

# Crybabies
[The science of emotions: Jaak Panksepp at TEDxRainier](https://www.youtube.com/watch?v=65e2qScV_K8)

[1998 Book: Affective Neuroscience: The Foundations of Human and Animal Emotions - Jaak Panksepp](https://academic.oup.com/book/53534)

[2018 The neurobiology of human crying](https://link.springer.com/article/10.1007/s10286-018-0526-y)


The parasympathetic nervous system conserves energy and slows the heart rate and is important for processes related to rest, recovery, and relaxation

# Reddit post on recent human evolution

What are some examples of evolution still at play in human development?
https://www.reddit.com/r/askscience/s/D1auQlquEM

There is actually a reasonably good Wikipedia article about this, which is not generally the case in this field and the main reason why I rarely cite Wikipedia in top-level comments in this sub:

https://en.wikipedia.org/wiki/Recent_human_evolution

Note that the term "evolution" isn't exactly what you're likely thinking of, which is probably selection. Evolution includes changes in allele frequencies due to random chance with neutral effects on reproductive success, the main instances of this is called **genetic drift**. Over evolutionary time, drift encompasses the bulk of overall evolutionary change, with compressed periods of major functional changes spurred by natural selection in response to environmental or ecological changes. Principles like **punctuated equilibrium** and **neutral theory** deal with this realm of observation.

A good way to think about this scenario is to conceive of the general phenotype of a species **at any given point of time other than just after major environmental or ecological change** as being a pretty good fit for that context, and that any given mutation (being random in incidence and location in the genome) is very unlikely to produce beneficial effects on fitness. This leads us to believe that the mutations which are mostly likely to remain over time are those which get trapped in the succession of filters preventing expression in the phenotype. They occur in non-coding areas, or they swap synonymous codons (though they themselves exhibit usage bias across genomes), *or they swap an amino acid which **does not** alter the folding structure or function of a protein*.

While detrimental mutations are subject to removal via selective forces, neutral mutations by definition impart no effect onto fitness and thus freely accumulate in the genome.

[complexity grows]

This process is happening and will always happen in our species (like all species), and will likely always encompass the majority of overall "change" in the human genome, even though it is not related to selection and resulting adaptation. This is completely irrespective of any change in the behavior or environmental experience of humanity: as long as our DNA is duplicating during cellular division, some errors will occur, and these errors are where the magic happens.

[creating is incomplete copying.]

Human reproduction has also become substantially more random since the advent of agriculture and even more so modern medicine.

While there are indeed still forces of sexual selection at play, the reasons for which we choose our partners are dramatically more subtle and nuanced, and it is not a foregone conclusion that they are not simply outweighed by the ever-present contribution of chaotic forces within the broader evolution. Think of it like the effect of weather on ocean waves.

Strong, torrential gusts can be potent enough to drive the waves in one unified direction and override smaller contributors to the current, but softer winds can lose their effect in the random noise of smaller waves going in every direction.

## punctuated equilibrium
In 1972, paleontologists Niles Eldredge and Stephen Jay Gould published a landmark paper developing their theory and called it punctuated equilibria.[1] Their paper built upon Ernst Mayr's model of geographic speciation,[3] I. M. Lerner's theories of developmental and genetic homeostasis,[4] and their own empirical research.[5][6] Eldredge and Gould proposed that the degree of gradualism commonly attributed to Charles Darwin[7] is virtually nonexistent in the fossil record, and that stasis dominates the history of most fossil species. [wiki]

https://en.m.wikipedia.org/wiki/Punctuated_equilibrium

# Motoo Kimura & neutral Theory

He is remembered in genetics for his innovative use of diffusion equations to calculate the probability of fixation of beneficial, deleterious, or neutral alleles.[4]

[Meaning he used ~random walk ~markov processes to study how genetic variation occurs. IMO showing how similar processes can describe vastly different molecular systems. Molecular logic.]

Combining theoretical population genetics with molecular evolution data, he also developed the neutral theory of molecular evolution in which genetic drift is the main force changing allele frequencies.[5]

# Apes

## Orangutans
Recently, it has been demonstrated that the red blood cells of humans and great apes (chimpanzees, gorillas and orangutans) have differences in their plasmalogen composition.[10] Total RBC plasmalogen levels were found to be lower in humans than in chimpanzees, or gorillas, but higher than in orangutans. Gene expression data from all these species caused the authors to speculate that other human and great ape cells and tissues differ in plasmalogen levels. Although the consequences of these potential differences are unknown, cross-species differences in tissue plasmalogens could influence organ functions and multiple biological processes.

# **Diffusion equation**

**Brownian motion**
The diffusion equation is a parabolic partial differential equation. In physics, it describes the macroscopic behavior of many micro-particles in Brownian motion, resulting from the random movements and collisions of the particles (see Fick's laws of diffusion

The **diffusion equation** is a **special case** of the convection–diffusion equation, **when bulk velocity is zero**. It is equivalent to the heat equation under some circumstances.

In math similar to:
Markov processess
Random walk
![image.png](https://hackmd.io/_uploads/ry4Ml6wQ6.png "Markov process" =150x)![image.png](https://hackmd.io/_uploads/SkHSx6DQT.png "random walk" =150x)

The particle diffusion equation was originally derived by Adolf Fick in 1855.[1]