It is the uniquely human capacity to create complex culture that has allowed us to become the most dominant and wide ranging animal on the planet. We travel the world, carrying our tools and our knowledge and we adapt our culture to help us to survive. The shelters and agriculture we create are ascribed to culture, as well as the division of labor and family structures we form. It is because of culture that we can survive in cold climates without fur, can kill meat without claws and teach our offspring the same methods. Our ability to adapt to our environment through the use of culture has permitted human societies to thrive in inhospitable environments. Our culture keeps us warm and well fed in areas where our species is not physically suited to live, much less procreate.
Because of our culture, the survival of our species is no longer dependent on good health, strength or skill, but on cultural adaptations. The smallest and least resilient human specimen among us is still likely procreate, which is the true test of the usefulness of any adaptation. Their genes will be passed to future generations and as well as their capacity for culture and their poor health. It is our culture, or more accurately, our capacity for culture that sets the human animal apart from other organisms on this planet. It is our unique ability to create and use tools, and then to share and expand that knowledge through the use of language and learned systems of meaning, that makes us uniquely human.
For me, the question “Why does 'culture' matter?” is really a bigger question beyond discussions of systems of symbols or the use of tools or the creation of customs and beliefs. For me, the question of 'culture' really seems to ask what exactly it means to be human. What is that thing, that spark of humanness that separates us from the cats and the dinosaurs? Culture. Culture is uniquely human.
It can be argued that other species have some ability to form culture as well. There are orangutans that have been taught to use sign language, so, isn't that culture? There are numerous species of animals that live in packs and form social groups with hierarchies and rivalries, that seems to be a sign of culture, right? There are even birds whose songs appear to be learned and passed down through each generation, and that is definitely cultural, isn't it? Yes, I think that a valid argument can be made that these other species have some capacity for culture, however it is not their primary means of adaptation. Orangutans cannot live in Siberia, no matter how much they express their desire to, and a pack of dogs will not survive a lean winter by harvesting their crops in the fall. My point is that culture is not a primary adaptation for any animal but the human animal, and so our capacity for complex culture is what makes us unique in the world.
Culture is language and social structure, it is community knowledge and learned behavior, and it is the way we dress and the the way we interact with each other. It is through culture that we learn become useful and contributing members of our societies and learn to survive and procreate in those communities. Culture is a million little things, as Clifford Geertz said in his Thick Description: Toward an Interpretive Theory of Culture, “...man is an animal suspended in webs of significance he himself has spun, I take culture to be those webs and the analysis if it it to be...an interpretive one in search of meaning.”
I agree with Geertz (with the exception of his using all male pronouns), culture is a complex web that we have crated, and most importantly, have used to procreate and ensure the survival of our species in to future generations.