The Comic:
http://images.ucomics.com/comics/ch/1994/ch940223.gif English is an exception because it is a creole language- a trade language that became spoken by natives. It's technically a mixture of Latin, Anglish, Saxon, Norse, and Danish. The reason we don't have genders is that was determined to complicate things too much for trade; who cares what gender something is when you only want to purchase it from someone?
That's also the reason that Korben Dallas is correct when he says he speaks two languages: English and Bad English. Bad English is perfectly understandable to Native Speakers, because the roots of the language allow it to be. There's no such thing as "Bad Chinese"- without knowing the right tones and sentence structure, you're screwed. Old English originally had a more Germanic structure and style, but when the french took control of Britain, the language shifted to be more in the style of a romance language.
The reason that we have two words for animals and their meat is because the hands tending the animals were not able to eat them, and the cooks called them what their employers called them. Thus, "Cow" (anglosaxon) to "Beef" (from French). "Lamb" to "Mutton", "Pig" to "Pork", "Deer" to "Venison"... the list goes on and on. Swear words, too, were originally descriptive: "Shite" was not a crass way of talking, it was the word for "fecal matter". "Fu**" had similar roots. Only after the french came did these words start to take on the perjorative meanings they have today, because it was percieved that the people using these words were themselves "rude and unkempt".
John McWhorter's Tower of Babel is a pretty good start on the subject of language in general, as well as a nice introduction to the field of linguistics (although I disagree with the man's politics, he writes pretty decent popular science books). He seems to follow Chomsky/Pinker's lead in the book, which is something you should be aware of while reading (there are a couple of other pretty valid ideas about language acquisition floating around in the field right now that he doesn't mention).
Old English (i.e. Anglo-Saxon) had both genders and a neuter...as well as three numberings (single, dual and plural) and a pile of cases (dative, nominative, ablative, etc, etc). A real bastard of a language.
Middle English retained alot of the gendered spelling from Old English words (which is why there're alot of extra 'e's in Middle English, like in "shoppe," etc) but didn't actually have genders...same deal with the wacky verb conjugations: all the verbs conjugate strangely (buy/bought, ran/run, etc) were regular conjugations in Old English that got carried over.