Evolution and Natural Selection
I believe in evolution. Or, at least, that’s it the best theory we have so far for how life came to be what it is today, and all the evidence (if correctly interpreted) is pretty convincing. I also just think it’s plain amazing: that, based on environmental stimulus, a species can change and adapt unwittingly over time.
Let’s take a quick look at what evolution really means.
The word itself comes from the Latin evolutionem, meaning “to unroll a book,” which I think is pretty cool. (I’m a total word nerd, so you’ll be getting a lot of etymological references around here.) The first widely-published ideas about natural selection are attributed by the well-known Charles Darwin, and a whole bunch of lesser-known men such as Alfred Wallace. A lot of other brains contributed and even originated important ideas around the articulation of evolution: writers were talking about the environment’s effects on species as early as the Greek and Roman times. The 1800s saw a rush of publishing and networking between researchers, and the broad dissemination of the information.
Darwin (LEFT) is best known for studying fossils, and later, the varying species living on the Galapagos Islands. Wallace (RIGHT) noticed a division in life on the island of Indonesia: on one side, things more closely resembled species in Australia. On the other side, things more closely resembled those found in Asia.
Evolution describes the changing of inherited traits of a population of organisms over successive generations. So a population can follow paths of new traits and eventually develop into a new species altogether. “Natural selection” describes the result of the process by which random mutations occur in a species’ inheritable traits (genes) and affect survival. Mutations can be negative and interfere with survival, but these traits are typically weeded out because individuals possessing them therefore kind of suck at surviving or procreating. Positive mutations actually aid in survival and so those individuals containing them survive to reproduce, passing those traits on to the next generation. Neutral mutations may be passed on or lost without great consequence.
Evolution is a process that theoretically takes an enormous amount of time, but the more generations a species produces, the faster it evolves. For instance, bacteria can evolve new traits – such as antibiotic resistance – in just weeks. This is the problem with commonly-used drugs both in hospitals and households.
For the next few days I’ll be highlighting some of my favorite examples of evolution. You’ll learn about toxic creatures, twins on opposite sides of the planet, triclosan, and goosebumps!
Posted on August 2, 2010, in Biology/Ecology and tagged antibiotic resistance, bacterial evolution, Darwin, evolution, generations, inheritable traits, mutations, natural selection, naturalist, nature, roaming naturalist, science, Wallace. Bookmark the permalink. 9 Comments.