The science of symmetry - Colm Kelleher

When you hear the word symmetry, you might think generally of triangles, butterflies, or even ballerinas. But defined scientifically, symmetry is "a transformation that leaves an object unchanged." Huh? Colm Kelleher unpacks this abstract term and explains how animal's distinct symmetries can tell us more about them -- and ourselves.

Lesson by Colm Kelleher, animation by Andrew Foerster.

[tomer]

He mentioned the mechanical advantages of being symmetrical. But most importantly, if you have a front and back end(head, tail), it is easier for DNA to repeat instructions laterally on both sides of the bilateral line, because, during cell division, it will take much more energy and time to duplicate a longer DNA strand for a non symmetric organism without any errors. As long as DNA can label where the front and back are facing so that arms or legs are not placed backwards, cell growing patterns in embryology become more straightforward. For those reasons, it is an advantageous adaptation because energy conservation can be used towards other adaptations which means greater fitness. It is also important for the outer layer of an organism to be symmetrical along with teeth.

[kevaran]

Having finished biology degree. Bilateral symmetry of mammals is generally external. Once you counted internal organs. The arrangement is not equal left and right.

[raptecclawtooth]

The actors are like: "im not enought paid for this"

[sultanahb]

am i the only one who actually enjoyed the video? xD for someone studying for her bio exam for hours i thought this was somewhat enjoyable lol.

[kunairuto]

I think this is my favorite TED narrator.

[white_shadow_]

The title should be the biology of symmetry.

[oldcowbb]

expecting more math, turns out it's more like biology

[ThePhatWabbit]

i thought we were going to get into quantum mechanics

[silenteyesamr]

Sorry, i could only think of "Dumb Ways To Die" video.

[TheBenenene]

Interesting talk, but STOP DANCING DAMNIT!

[kurrizzle]

Genetics are even more important than symmetry in figuring out the tree of life. Similar phenotypic characteristics can pop up in separate places totally on their own. Symmetries are important to understand in phylogeny if there is some sort of discrepancy in genetic lineage, but it is supplementary information, more than anything else, in determining the tree of life. The beginning of the video veered off course into biology rather than sticking to a discussion of symmetries in all subjects, and made conclusions that, although correct, are not thoroughly discussed in respect to all other subjects. 

[Lucuskane]

Knowledge (singing note), awesome, how a topic(excerpt) like this just hits you out of nowhere  

[darkrules]

I remember the episode of cyber chase where they talk about symmetry. You forgot about slide symmetry which mainly implies to long things like fences and combs

[doncorleone]

When I hear Symmetry I hear: Gurl u getting an A+ on this Test! 😂😂😂

[theepicsandwichgoc]

4:40 the way u said "when reminds me of hot rod whiskey scene xD

[plethrons]

 The animation of this video is so nice! way better than mine :)

[HienNguyenHMN]

I know some people HATE it when others say this about them, but:
I love his accent. :)

[michikomanalang]

“Some Carls don’t exhibit any symmetry at all” I love this accent DEEPLY

[talalzahid]

Symmetry is not only in biology but it is found in the whole universe. From an atom to the biggest galaxies, all have some kind of symmetry involved and if you are smart enough to visualize this then I am sure you will find symmetry everywhere. Physics is arguably all about symmetry!

[JWentu]

may I suggest to read some Richard Dawkins' book to understand why we are bilateral and no, say, 90° rotational symmetric...; basically it's a matter of economy. it's better, as a fish, to differentiate a head from a tail (like they said in the video), it's good also to differentiate an top part from a bottom part (this simmetry is broken by gravity that pulls in the vertical direction) but there would be no gain in differentiating left from right... therefore evolution lead to an economy by having left and right look the same.