In organisms that reproduce sexually speciation isn't about becoming "something else". it occurs when two initially related populations become so genetically distinct that they are no longer able to interbreed with each other without their offspring losing biological fitness. Mules and horses for example can breed with each other but their offspring is infertile - a drastic loss of fitness. Phenotypical similarity isn't an indicator of speciation at all - wolves are more similar to coyotes than to shih tzu but neverthless, they are more closely related to shih tzu than to coyotes. There is also so called convergent evolution - some species may develop similar traits due to similar evolutionary pressures. Wolves are very similar to Tasmanian tigers but are only distantly related.
Ad 2 - I agree that not all words have a common "parent" (words do not arise due to sexual reproduction so they can't have parents). However, languages also evolve though via more or less different mechanisms than biological evolution and there are families of languages which are descended from a common ancestor. My native language belongs to a West Slavic branch of Slavic languages, itself belonging to Indo European family. All Romance languages (French, Spanish, Italian, Romanian etc.) are descended from Vulgar Latin which was a homogenous language around 500 AD but then began to differentate into separate languages because of geographic and political isolation of it's speakers. If you believe in creationism, do you believe in linguistic creationism as well? Do you think that e.g. lexical, grammatical and phonetical similarity of all Slavic languages is just an evidence of creation but not evolution?
Ad 2 - I agree that not all words have a common "parent" (words do not arise due to sexual reproduction so they can't have parents). However, languages also evolve though via more or less different mechanisms than biological evolution and there are families of languages which are descended from a common ancestor. My native language belongs to a West Slavic branch of Slavic languages, itself belonging to Indo European family. All Romance languages (French, Spanish, Italian, Romanian etc.) are descended from Vulgar Latin which was a homogenous language around 500 AD but then began to differentate into separate languages because of geographic and political isolation of it's speakers. If you believe in creationism, do you believe in linguistic creationism as well? Do you think that e.g. lexical, grammatical and phonetical similarity of all Slavic languages is just an evidence of creation but not evolution?