
Our Understanding of Giraffes Does Not Measure Up - dnetesn
http://www.nytimes.com/2014/10/07/science/our-understanding-of-giraffes-does-not-measure-up.html?hp&action=click&pgtype=Homepage&version=LargeMediaHeadlineSum&module=photo-spot-region&region=top-news&WT.nav=top-news
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3JPLW
I was hoping the article would mention something about their neuroscience,
too. From a control systems perspective, it's rather remarkable that they're
able to stand upright. They have similar nerve conduction velocities as we do…
but have much longer latencies[1]! It'd be interesting to do further studies
and simulations of the control system requirements with such a long delay.

1\.
[http://jeb.biologists.org/content/216/6/1003.full](http://jeb.biologists.org/content/216/6/1003.full)

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icegreentea
Remember that a lot of 'standard' movements aren't fully controlled from the
brain. Instead, the brain generators modulating signals to structures/systems
lower in the spinal - ie increasing or decreasing your rate of walking.
There's lots of evidence of these 'Central Pattern Generators' being located
below the brain - which would reduce signal lag.

For a somewhat disturbing example of this, here's a 'decerberated' cat on a
treadmill.

[https://www.youtube.com/watch?v=wPiLLplofYw](https://www.youtube.com/watch?v=wPiLLplofYw)

That said, the fact that any vertebrae (even our selves) are able to move and
react so well is pretty amazing, given that our own neural lag is in the
~100ms range. It's really a testament to the robustment of the multi-tier
control that we (animals in general.. but especially large animals) have
evolved.

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scrumper
Fascinating (if a little hard to stomach) video. This seems to imply that
bipedal locomotion is learned, while quadrupeds have the skill hardwired into
lower-level structures. (Certainly, having watched my eldest figure it out, it
doesn't seem to be an innate ability in humans.)

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icegreentea
Just because the structure resides below the brain, doesn't mean that it's
simply 'innate'. For example, while deer fawn are famously able to start
walking right away, a kitten is actually pretty terrible at walking for many
weeks - they still have to learn. Perhaps part of the difference between the
'apparent' skill of quadrapedal and bipedal learning is that a) quadrupedal is
inherently easier (its more stable, more forgiving of small deficiencies), b)
bipedal 'failure' is a lot more drastic (especially when you have the
proportions of a child.. you don't have a lot of leg to catch yourself), and
c) we're simply more familiar with bipedal motion, and therefore more critical
of flaws on observation.

In addition, there is suggestive evidence that human bipedal motion is CPG
driven [1]. I think a reasonable analogy to draw is that at birth a CPG is
kind of a lower level controller, all hooked up, but not yet programmed. It
takes time and practice to tune and program the controller to generate useful
output.

[1]
[http://brain.oxfordjournals.org/content/117/5/1143.abstract](http://brain.oxfordjournals.org/content/117/5/1143.abstract)

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scrumper
Interesting - thanks.

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lun4r
"June 21 is World Giraffe Day — the longest day for the tallest animal" :D
What animal should be celebrate on Dec 21 then?

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fian
June 21 is the longest day only for the northern hemisphere. The southern
hemisphere would therefore celebrate giraffes on the (or about) the 21st Dec.

Also, from a cursory search, giraffes occur both north and south of the
equator in Africa. So neither northern or southern hemisphere could lay sole
claim to picking a day.

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mcv
But around the equator, the length of the day barely varies, so the entire
idea behind it is lost.

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sklogic
Those Voronoi things are fascinating indeed.

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sparkzilla
Giraffes are heartless creatures

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pselbert
Perhaps your comment is a reference to something that I don't know about, or a
sarcastic quip. However, it is in direct conflict with the substance of the
article:

"Female giraffes, for example, have been found to form close friendships with
one another that can last for years, while mother giraffes have displayed
signs of persistent grief after losing their calves to lions."

In fact, the emotional behavior of giraffes is a focal point of the article.

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ufo
its a reference to this image, btw:
[http://viciulgandirii.files.wordpress.com/2012/03/giraffes-a...](http://viciulgandirii.files.wordpress.com/2012/03/giraffes-
are-heartless-creatures.jpg)

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bunkat
Why are there so many random NY Times articles ending up on the front page
lately? Back 6 months ago I never remember seeing these articles and now there
seems to be one hitting the front page every day. I could understand if they
were relevant technical articles but one about giraffes?

The worst part is they create very poor discussions where most of the comments
get down voted because what can one really say about a story about giraffe
evolution?

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Jtsummers
Because someone submitted them and others up voted them. Don't compain just
flag it or ignore it.

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bunkat
So if a group of people wants to change the fundamental focus of this site
from technology to animal evolution we're not allowed to say anything about
it? Flagging doesn't do anything because too many people take your approach of
just ignoring it (or worse down voting any concern as complaining).

There definitely seems to be a growing group of users who are looking to
greatly expand the scope of this site and to me that dilutes the quality of
the site.

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Jtsummers
1\. I don't down vote comments like yours because I try not to down vote (I
once down voted in anger and felt bad, ever since I've reserved them for the
most ignorant comments I come across and rarely even bother then).

2\. If I ignore it, I'm not up voting it. I'm up voting posts that I think
have some value.

3\. This site is about whatever people on this site find interesting. If
evolution (an interesting subject) happens to come up, it'll likely get up
voted and discussed.

4\. We get some slow days when it's mostly fluff here. And then we get days
when it's nothing but academic math papers. It comes and goes, deal with it.

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percentcer
NYTimes doesn't let you highlight text?

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theGimp
I'm able to highlight text using a mouse.

