150 years ago today, what is probably the most important book in all of science, and definitely the most important book in all of biology, was first published.
Origin of Species.
I quote from the book:
There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
Our understanding of how the world works has changed immensely in the past 150 years, and much of that was due to the publication of this book. We now understand how diseases evolve (so there's a new flu virus every year, and HIV is impossible to stop). We now understand who pesticides only work for so long (the animals they're used on evolve).
Almost every big idea in biology--how organisms change, genetics, DNA, ecology, etc.--has been discovered in the past 150 years, and much of that has to do with Charles Darwin's research.
What a great time to be alive.