Why humans and lots of animals have 5 fingers and 5 toes, and not 4, or 6, or more, or less?
349227
CHECK THE NUMBER OF CHROMOSOMES OF HUMAN, IT IS FIXED AT 48, BUT HUMAN WITH MORE OR LESS NUMBER OF CHROMSOMES TEND TO DEVELOPED OTHER PHYSICAL FEATURES THAT IS CONSIDERED ABNORMAL.OTHER ANIMALS HAVE THEIR NORMAL NUMBER OF CHROMOSOMES THAT INFLUENCED THEIR PHYSICAL FEATURES INCLUDING THE NUMBER OF FINGERS.
446873
by primitive and advanced, a paleontologist doesn't mean the same thing as one normally thinks of when you hear 'primitive' or 'advanced'.\n\nPrimitive means closer to the ancestral form, unmodified from that which has been inherited through phylogeny.  A more proper term would be plesiomorphic.  Two groups which share a plesiomorphic trait, such as five fingers, would be synplesiomorphic, suggesting that those lineages inherited the trait from a common ancestor.  For example, bats, humans, tree frogs and monitor lizards would share the synplesiomorphy of five digits on the forelimb.  This trait can be traced back to the Rhipidistian Sarcopterygian fish.  Primitive does not mean inferior, only that it has not been modified from the ancestral state.\n\nAdvanced, derived or synapomorphous traits are ones that have been modified from the ancestral condition.  The two digits of the T. rex are highly derived from the original five digit condition.  So is the two foreclaws possessed by the two-toed sloth.  These traits, although highly derived, so not share a similar phylogenetic origin.  They also are not necessarily superior to five gigits, or 'more evolved', they are simply an adaptation in that lineage that has taken place that is different that the adaptations that earlier organisms in that lineage possessed.\n\nThe reason we (and all tetrapods) have five digits as a primitive trait is due to the fin structure of that first fishie that started wandering out on land and becoming the first amphibian.  Those Sarcopterygians had a number of bony ossicles in their loby fins that helped provide some support to their fleshy fins as they pushed their way onto land.  It just happened that those ossicles were arranged in more or less five rows, and these rows eventually became adapted to become the digits of our ancestral amphibian great-grandparents.  Had we evolved from the Actinopterygians (ray-finned fish), perhaps we'd have thirty or forty fingers.  Who knows?
1138358
Each finger has its own distinctive mark. So, the answer is they are different.
335802
It's a mutation of their genes. It's natural, and not at all a problem. Sometimes I'd like to have an extra finger on each hand. Mostly when I was playing clarinet and needed to stretch my fingers farther.\n\nPolydactyly is the medical term for having an extra finger or toe. There is an interesting list of polydactyl people on wikipedia.org.\n\nhttp://en.wikipedia.org/wiki/List_of_polydactyl_people
1049595
Yes. The bones in your toes and fingers are called phalanges. Your pinky toe has 3 bones.  (The thumb and big toe have two phalanges, while the other fingers and toes consist of three.). You may be able to look it up in a reference book if you need more details.
309417
Dr d is right, everything depends on the environment and our own selection choices, however s/he is wrong to say these cannot be predicted.\n\nOne can predict that we will live less active lives and will have less requirement for fitness, altough that is not to say that fitness traits will be lost.  There is absolutely no reason for us to go bals or lose fingers if there is no selection for them.\n\nIf man stopped using his little finger (pinky) it would not be lost this is because change only occurs when there is pressure for it to do so.  Man would be no less 'fit' with or without the fifth finger so it would remain, unless men and women decied it was sexy to have four fingers and only individuals with smaller fifth fingers ever bred.  This would cause a shift towards fewer digits, but come on, this would not happen.  \n\nOther answers are correct for saying that our diets and environmental conditions may affect our health and body weight.  For example diabetes is becoming more prevalent in the USA so we might expect natural cases of diabetes to increase, but in 2000yrs it is likely this will have been addressed.
961364
Fingers are on hands, and toes are on feet.
126743
There are 26 bones in the human foot (28 if you include the sesamoid bones at the base of the big toe). These are: the Talus, which connects to the tibia at the ankle; the Calcaneus, which forms the heel; the Navicular, Cuboid, and three Cuneiforms (Medial, Intermediate, and Lateral), which form the middle of the foot; the five Metatarsals, which radiate out to the toes; and 14 Phalanges (2-3-3-3-3), which form the toes.\n\n\nThere is a nice diagram of the foot at:\n\nhttp:// www.asianconnect.com.sg/health/mdasample/anat3.html\n\nand a color-coded X-radiogram of the foot at:\n\nhttp://indy.radiology.uiowa.edu/Providers/Textbooks/ JointFluoro/Ankle/Ankle.med.08.html
862514
A "hallux" is the first or inermost digit on a human's (er primate's, or whatever) foot... as in, your big toe. I think in birds, the hallux is the one toe that points backwards. But ostriches don't have one of those things... They just have two toes.
500548
People are like all animals, if you buy a poodle its parts are small you buy a Great Dane and its parts are bigger. same for humans someone 6 foot 4 is going to be bigger everywhere compared to someone 4 foot 11
884467
5 due to the average person's toes was designated as\n   the second number system.  In say 2 million BC in the worst\n   anomales of sciences, even the biblical files of Babylon says\n   that people became frightened of God, the angels, and resort\n   to smaller interactions was common, and taught to the kids.\n   Because the weirdest types become religious fanatics and\n    go in on tatoos, and mutilations, there was a very very high\n    priest of mention.  Schafer the cartoonist made his very\n    early appearance onboard the explorer 2 of Vulcan peace plan.\n   He insisted that the planets would want more automotive\n   parts shoppes and started a revolution to make wheels more\n   hexagonal.  Needless to say what happened was he won out,\n    because the south rose again, and threw out the farm block.\n    No we have writting most likely by Plato, or Caesars agro\n    ancesters who then escaped to california.  But the people of\n    the next mission landed on a real runway with lights and found\n    that increments in speed limits were a new developing life\n     style and planning committee.  The 45 became a living legacy\n    and early prehistoric or prehisterical shannon sang our hit.\n    Wake up little suzy, thus the number 5 started as an alarm\n     clock and today we know of the study of ooga, the first writting.
684283
It would be nice if I had 4 arms and 4 hands. But to anser your question..... NO!
175
According to a column that I read written by Joël Carbonnel, "Nature has never been able to count above five."\n\nA researcher has discovered that when the limbs have more than five digits they become distorted into a bow-legged shape which seriously interferes with normal walking or running.\n\nhttp://www.positivehealth.com/permit/Articles/Regular/joel74.htm
836762
Technically, we don't differ from primates since Homo sapiens are primates.  Monkeys, lemurs, apes and hominids all belong to the order Primates.   \n\nI'm assuming your question is "How do we differ from other primates?"  So, I'll answer that instead.  \n\nWe are unlike the other primates physically in that we do not have opposable thumbs on our feet.  Our hipbones are structured differently to facilitate vertical walking.  Due to this, unlike other primates, humans are the only obligatory bipedal primates.  One misconception is that humans are hairless relatives of apes.  In fact, we have just the number of hair follicles per square centimeter of skin that one would expect on an animal of our size.  It's just thought our hair is unpigmented and finer and shorter than most other animals so it's not as visible at a glance.    \n\nApart from physical characteristics, our advanced brain size and capacity exceeds that of lesser primates.  This allows us to have abstract thought and use logic and other ideas that lesser primates are capable of.  Our use of tools and external objects to compensate our physical shortcomings is unrivaled not only among other primates, but among all other organisms.  \n\nWe do have some common characteristics with primates.  After all, we are supposed to have descended from a common ancestor.  Like other primates, we have opposable thumbs on our hands.  Also, all primates have five fingers (not counting my old shop teacher, Mr. Windslow).  All primates have fingernails instead of claws, or other keratinous apendages.  In general, primates are social creatures.  All primates also have forward facing eyes, useful for depth perception.  Humans are similar to most primates in that we are both omnivorous, meaning that we have the physiology to eat and digest both plant matter and meat.
882099
We humans are known as a "small species", rather as cheetahs are. We both went through a " bottle neck " event that reduced species size considerably. So that very few became the ancestors of very many.\n\nPS Cheetahs are a " smaller " species than humans are.
570245
A human finger, or was it a toe
494185
most mammals have four appendages, they just evolved differently. humans evolved into arms and legs with very different uses. rodent type animals have front feet they can use as hands, as do most monkeys. beasts of burden and their predators maintained four legs for obvious reasons.