Letty Posted July 21, 2008 Share Posted July 21, 2008 Great question...When you look at the overal shape our finger sizes produce, it makes the hands look like fins. According to the theories of evolution weren't we once aquatic creatures? Aha, the pentadactyl limb!! I had an amazing diagram that I got once, but this will suffice. Link to comment Share on other sites More sharing options...
MoogleViper Posted July 22, 2008 Share Posted July 22, 2008 I love how you are generalising the WHOLE entire female population in one swoop. Not the entire population, just the vast majority. Link to comment Share on other sites More sharing options...
Supergrunch Posted July 22, 2008 Share Posted July 22, 2008 Aha, the pentadactyl limb!! I had an amazing diagram that I got once, but this will suffice. This is the 1:2:5 thing I was saying. Also: Too tired to qualify pictures with words. Link to comment Share on other sites More sharing options...
Sheikah Posted July 22, 2008 Share Posted July 22, 2008 Well, I can't answer the explanation behind why our fingers are of different length (as in, its evolutionary purpose), but I can explain why they are of different length (advanced developmental biology here). At the bottom (or posterior) of the limb bud, the ZPA (Zone of Polarising Activity) is situated, which secretes a diffusible ligand morphogen called Sonic Hedgehog (I kid you not, and it's abbreviated to Shh). Shh concentrations determine the differential Hox gene (genes that determine digit identity) expression along the anterior-posterior (thumb to little finger) hand axis. Where there is practically no to little Shh, earlier Hox genes are dominantly activated and the thumb forms, while high levels determine more posterior digits. Shh has been found to be irregular in the ZPA in some diseased patients, where overexpression results in a lack of thumbs and more numerous and similar length digits, while the lack of Shh results in fewer digits and thumbs only. Interestingly, Shh is involved in midline separation...I don't know if any of you have seen pictures of an incident that happened in the 60's where many sheep were born as cyclops (holoprosencephaly), but it was later found that the sheep's mothers grazed on plants that were covered in cyclopamine...resulting in Shh inhibition. Some scary pics can be found for Shh deficiencies. Scary but interesting. Link to comment Share on other sites More sharing options...
Raining_again Posted July 22, 2008 Share Posted July 22, 2008 While we're on the topic: Why do some people have "finger toes" and some don't? I don't... I find finger toes a little weird Link to comment Share on other sites More sharing options...
D-Day Posted July 22, 2008 Share Posted July 22, 2008 While we're on the topic: Why do some people have "finger toes" and some don't? I don't... I find finger toes a little weird I remember reading somewhere that our feet are naturally supposed to have similar functions as our hands, but over time (minor evolution) for different reasons (such as wearing shoes amongst others apparently), out feet are as they are. Uuuummmm, maybe thats the reason. Lately I've been thinking about walking the streets with no shoes, but realised that it's not such a good idea. I'll just have to let the dream of using my feet just like my hands slip by Link to comment Share on other sites More sharing options...
Blue_Ninja0 Posted July 22, 2008 Share Posted July 22, 2008 What the hell is a finger toe? Link to comment Share on other sites More sharing options...
Fierce_LiNk Posted July 22, 2008 Author Share Posted July 22, 2008 Note to Jayseven: Oh, how you laughed. Three pages, fothermucker! THREE PAGES! of people talking about fingers. Hwoar! *thrusts* Raining_Again: Finger toes are so funky, but not as funky as people who have a huuuuge big toe. God, I want to poke them with a stick its so cool. Link to comment Share on other sites More sharing options...
Raining_again Posted July 22, 2008 Share Posted July 22, 2008 What the hell is a finger toe? 2nd toe longer than big toe. LOL finger toes are creepy fierceyy eww Link to comment Share on other sites More sharing options...
Eenuh Posted July 22, 2008 Share Posted July 22, 2008 2nd toe longer than big toe. LOL finger toes are creepy fierceyy eww My second toe is longer than my first one... =( *feels ugly* Link to comment Share on other sites More sharing options...
Raining_again Posted July 22, 2008 Share Posted July 22, 2008 My second toe is longer than my first one... =( *feels ugly* awh your not ugly I just find them strange because i don't have them... maybe its a sub-concious jealousy :P Link to comment Share on other sites More sharing options...
Fierce_LiNk Posted July 22, 2008 Author Share Posted July 22, 2008 Wait, I thought finger toes were toes that looked like fingers, so that your foot looks like a hand? Link to comment Share on other sites More sharing options...
Raining_again Posted July 22, 2008 Share Posted July 22, 2008 Wait, I thought finger toes were toes that looked like fingers, so that your foot looks like a hand? It's when your second toe is bigger than your first, just like how your middle finger is bigger than your index finger. Link to comment Share on other sites More sharing options...
Fierce_LiNk Posted July 22, 2008 Author Share Posted July 22, 2008 It's when your second toe is bigger than your first, just like how your middle finger is bigger than your index finger. Technically then shouldn't it be your third toe is bigger than the second? Hmm, I guess I got that wrong. I think feet that look like hands, and also people who 'hold' objects in their toes, like pens and other such things...thats pretty strange! Link to comment Share on other sites More sharing options...
Supergrunch Posted July 22, 2008 Share Posted July 22, 2008 Well, I can't answer the explanation behind why our fingers are of different length (as in, its evolutionary purpose), but I can explain why they are of different length (advanced developmental biology here). At the bottom (or posterior) of the limb bud, the ZPA (Zone of Polarising Activity) is situated, which secretes a diffusible ligand morphogen called Sonic Hedgehog (I kid you not, and it's abbreviated to Shh). Shh concentrations determine the differential Hox gene (genes that determine digit identity) expression along the anterior-posterior (thumb to little finger) hand axis. Where there is practically no to little Shh, earlier Hox genes are dominantly activated and the thumb forms, while high levels determine more posterior digits. Shh has been found to be irregular in the ZPA in some diseased patients, where overexpression results in a lack of thumbs and more numerous and similar length digits, while the lack of Shh results in fewer digits and thumbs only. Interestingly, Shh is involved in midline separation...I don't know if any of you have seen pictures of an incident that happened in the 60's where many sheep were born as cyclops (holoprosencephaly), but it was later found that the sheep's mothers grazed on plants that were covered in cyclopamine...resulting in Shh inhibition. Some scary pics can be found for Shh deficiencies. Scary but interesting. Sonic hedgehog is just plain awesome, I love the way those chicken embryo experiments correspond so well with Wolpert's French Flag model, especially with the low concentration -> keratin, intermediate concentration -> brachyury, high concentration -> goosecoid. (incidentally, relative "digit" size actually means something in a flying bird, again suggesting some degree of vestigiality in humans) And Hox genes in general are cool - I love the way they are expressed in the order they appear on the genome, both chronologically and positionally. Fun things to do with arthropod speciation too... [/geek] Link to comment Share on other sites More sharing options...
Raining_again Posted July 22, 2008 Share Posted July 22, 2008 Technically then shouldn't it be your third toe is bigger than the second? Hmm, I guess I got that wrong. I think feet that look like hands, and also people who 'hold' objects in their toes, like pens and other such things...thats pretty strange! Technically it should, but shush yer face bucko =P Link to comment Share on other sites More sharing options...
weeyellowbloke Posted July 22, 2008 Share Posted July 22, 2008 I have a finger toe and it's awesome, I can cross my toes like my fingers. I think you're all just jealous you don't have multi purpose feet. I'm guess finger toes exist due to our ape ancestry, a remanent from our days living up in the trees before coming down to evolve on the plains. I'm a throwback! Link to comment Share on other sites More sharing options...
Shino Posted July 22, 2008 Share Posted July 22, 2008 Its so unfair that evolution decided we only need feet instead of a hand. Why fix something that is awesome? And practical too. Link to comment Share on other sites More sharing options...
jayseven Posted July 23, 2008 Share Posted July 23, 2008 YOu're right flinky. I am envious that you got three pages for LOLS rather than two or one, which would'v been SHAMEFIL. Link to comment Share on other sites More sharing options...
Fierce_LiNk Posted July 23, 2008 Author Share Posted July 23, 2008 YOu're right flinky. I am envious that you got three pages for LOLS rather than two or one, which would'v been SHAMEFIL. Go Eat Shit. Pisshead. WeeYellowBloke: My housemate sits kinda cross legged and has one of her legs over the other, and she holds objects like pens and remote controls and stuff between her toes... I just find it strange. It's like she has 3 hands. Link to comment Share on other sites More sharing options...
Falcon_BlizZACK Posted July 23, 2008 Share Posted July 23, 2008 Aha, the pentadactyl limb!! I had an amazing diagram that I got once, but this will suffice. I, uh, don't get it. What is it trying to prove? Or is it just illustrating evolution? Link to comment Share on other sites More sharing options...
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