Medical testing on animals (such as cancer fighting drugs in rats), organ transplants from animals (such as pig heart valve transplants), and gene implantation (such as into bacteria to synthesize insulin) all depend on the notion that we share common biomolecular processes and structures. We have these commonalities because we share a common ancestor that also shared those traits. Knowing that gives us the power to predict new treatments and innovations that can and do save lives.
In order to be able to keep up with bacterial (like MRSA), viral (like SARS, H1N1, HIV), fungal, and protist infections we need to understand the governing principles and mechanics behind their origin and evolution. Each of those four categories requires very different treatment because of their differing traits and evolutionary histories (like differences in cell walls, ribosomes, and immune response). Knowledge is power when it comes to being able to make predictions about which research and treatments to pursue.
Agricultural ReasonsJust about everything your average person eats has been modified by humans in some way. Wild mustard is just one easy example that demonstrates the power this process of artificial selection has. Being conscious of the evolution of food informs one's decisions about seed banks, genetic modification, ecology, biodiversity, maintaining diversity to lessen disease attacks, etc.
Evolutionary Psychology ReasonsOur minds, like the rest of our body, are the product of evolution and its change agents, like natural selection. Evolutionary psychology, while often speculative, has the ability to reveal the sources of both our strengths, like our care for each other, generosity, ability to forgive wrongs, intelligence, empathy, etc., and our weaknesses, like our fear, greed, anger, out group/in group bias, etc. Being aware of these and exploring its implications gives us the insight needed to strive towards being the best individuals and societies we can be. Far from a license to act "like an animal" it is a call to at times resist our evolutionary inclinations and live a fulfilling life according to wisdom and ethics of today rather than according to what was adaptive in the often harsh ancestral environment we came from. When dealing with others it also gives us the space we need to be patient and understanding--we are all a work in progress.
Biological Understanding Reasons"Nothing in biology makes sense except in the light of evolution." -Theodosius Dobzhansky, evolutionary biologist and Russian Orthodox Christian. Trying to understand biology without evolution would be like trying to get a PhD but not being able to read. You can try. You just won't get very far.
Conservation ReasonsUnderstanding population genetics, adaptation, and that each population has a unique and precious evolutionary history is essential to productive, long term conservation.
This is your story! What could be more important than that?