
Mice Change Their Appearance as a Result of Frequent Exposure to Humans - Erlangolem
http://www.media.uzh.ch/en/Press-Releases/2018/Self-domestication-House-Mouse.html
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pvaldes
Another possible explanation could be that animals feeded on an artificial
monotonous diet and set free from predation pressure, start showing
genetic/colour defects quickly. Similar colour issues happen with captive
birds and fishes unless we provide extra charotenes to complete its diet. In
the wild the diet is much more diverse and finding charotenes is not a
problem.

Or that when the mice population increases the animals just fight more.
Domestic mouse males fight and bite other males. Mother with litters will
attack males also. More animals in the same place = more scars by bites, and
this could easily lead to an increase on white (regrown) hair patches. A
simple explanation that does not depend on human contact. Is normal in birds
to create white feathers after a predation event to quickly replace missing
ones and cover bald patches.

And another explanation could be that when the mice population increases,
their individual size decreases because there are less food for each one (and
different hormone interactions non necessarily human related). If we extract
some of those mice and put it in a new cage subject to the same human
manipulation but with a more diverse sources of food, would the average skull
size quickly increase again? Would the animals with white patches decrease? I
bet that yes.

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hchasestevens
Yes, these are all possible explanations, but the specific symptoms observed -
development of spots and smaller cranial capacity - are well documented as
common effects of human domestication across a broad range of mammalian
species. That the same mechanism is driving the changes observed in these mice
would be a simpler explanation than various disparate, piecemeal effects
combining to produce them.

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pvaldes
Domestication, like in the foxes study, needs a small genetic pool to work and
a deliberate selection of the sexual reproduction by humans (killing the non-
desired ones, mating only animals with desired traits). Nothing of that is
happening here.

One of the problems with the article is that does not try to discard those
explanations. A simple check to investigate if white spots are linked to sex
or age would help. A check for scars in those patches would positively help us
to understand what is happenning. It does not mean necessarily harming the
mice, they could just rasurate some white patches and take a look.

We are concluding that animals sort of "deliberately increase" their
"cuteness" to please humans but this conclusion is not justified. What if
aggression is just being increased as response to animals being marked with
strange human odour?. This kind of articles should discuss at least some of
those alternative explanations.

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fcbrooklyn
The article claims that the animals were not exposed to selection based on
their domesticity, but it includes this line "These animals are regularly
provided with food and water, and investigated by the researchers."

It strikes me that that situation represents a selection pressure, because
mice that are more afraid of humans, are likely to avoid a place where they
are regularly present, and thus lose the advantage of the risk-free meal
ticket these particular humans are providing.

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conductr
Along same line. With wolves, the aggressive ones were likely shooed away or
killed. Either way it’s selection or a learned then taught behavior pattern
change.

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lisper
Also observed in foxes:

[https://en.wikipedia.org/wiki/Domesticated_red_fox](https://en.wikipedia.org/wiki/Domesticated_red_fox)

"Russian scientists achieved a population of domesticated foxes that are
fundamentally different in temperament and behavior from their wild forebears.
Some important changes in physiology and morphology became visible, such as
mottled or spotted colored fur. Some scientists[citation needed] believe that
these changes obtaining from selection for tameness are caused by lower
adrenaline production in the new population..."

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hchasestevens
For those interested in hearing more about phenotypic changes in domesticated
mammals (many of which also apply to humans), I'd recommend "The
'Domestication Syndrome' in Mammals: A Unified Explanation Based on Neural
Crest Cell Behavior and Genetics" (link:
[http://www.genetics.org/content/genetics/197/3/795.full.pdf](http://www.genetics.org/content/genetics/197/3/795.full.pdf)).

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oliv__
Makes you wonder if humans do the same with their surrounding peers?

~~~
csours
[https://en.wikipedia.org/wiki/Self-
domestication#In_humans](https://en.wikipedia.org/wiki/Self-
domestication#In_humans)

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_bxg1
Makes me wonder if the anatomical features humans consider "cute" actually
have a root in being real predictors of timidity.

~~~
rsuelzer
My initial thought was that it would make sense to make yourself as cute as
possible if you want humans to leave you alone.

~~~
lisper
[https://en.wikipedia.org/wiki/Heikegani](https://en.wikipedia.org/wiki/Heikegani)

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cm2187
One interesting aspect is the idea that more than just natural selection is at
stake in the evolution of our gene pool. That some genetic features may be
dropped or changed if not required anymore without the pressure of a higher
death rate / lower reproduction. Another example is wisdom teeth, which aren't
really useful anymore given that we cook meat. They are slowly disappearing
but not as a result of natural selection. Darwinism doesn't seem to explain
everything, there must be other mechanisms involved.

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edmccard
>That some genetic features may be dropped or changed if not required anymore
without the pressure of a higher death rate / lower reproduction ... darwinism
doesn't seem to explain everything

If the results of a newly-introduced selection pressure can be explained by
darwinism / natural selection, then surely so can the results of a removal of
selection pressure.

For example, if there are genes that result in lowered fear or agression, and
that leads to fewer offspring for wild mice, they will have a lower frequency
in a wild mouse population than in a population where they don't lead to fewer
offspring. I'm no expert, but it doesn't seem like this particular article
requires any additional mechanisms beyond natural selection.

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Ancalagon
Wow this is fascinating. I didn't realize changes in the adrenal glands could
so rapidly and dramatically alter a species. What evolutionary pressure to
domestic themselves would these animals have if they werent coming into
contact with people regularly?

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Erlangolem
Link to the original study:
[http://rsos.royalsocietypublishing.org/content/5/3/172099](http://rsos.royalsocietypublishing.org/content/5/3/172099)

