Evolution “is nothing more and nothing less than adaptation to the local environment.” The local conditions, however, change randomly, i.e. there is no direction in their change. How is it possible then that evolution can lead to the appearance of such complex species as the Homo sapiens?
You can imagine that at every turn, there were some individuals who were well-enough adapted to the environment that they survived to have children.
Now, the funny thing is, our ancestors were pretty social (watch monkeys some time). The big brains we have are more adapted to socializing with our own kind — sort of a self-guided selection process, with the outcasts and pariahs having fewer children.
Is it any wonder we like soap operas so much?
It took a LOOOOOOOOONG time. As opposed to the 7 day theory you probably believe in.
Most people cannot truly fathom geological time. Life has been evolving for 4 billion years. That is a very, very, very long time.
Evolution is not only adaptation it is also due to survival of the fittest. And it is impossible for any of us to imagine just how long 4.5 billion years is.
Hmm … copy-paste much?
Here’s a word-for-word copy of this question:
http://answers.yahoo.com/question/index;_ylt=AqE3eb.9EJ8S3KzNxoO3gzHty6IX;_ylv=3?qid=20080329042240AAL8wge&show=7#profile-info-9i6iukPEaa
And this one:
http://in.answers.yahoo.com/question/index?qid=20080311125930AAjX1Zh
Oooh … and here too:
http://www.topix.com/forum/news/evolution/TOP1HC5V06HTVUP5U
And here:
http://richarddawkins.net/forum/viewtopic.php?f=4&t=40169&p=775563
What is it with Creationists and copy-pasting each other’s questions? Is it really that hard to think for yourself?
….
The answer TIME.
DEEP TIME.
Everything you are saying is correct. But they are precisely why evolution is so powerful.
For example, yes, conditions change … but they also can be very constant … year after year, millenia after millenia … but then change significantly over millions of years. It is precisely because (as you say) “there is no direction” to the change in conditions, that there there is no direction in evolution. A species is adapting to whatever conditions are in effect *at that time*. When conditions change again, then the species changes again as a result.
Or to put it another way, if the conditions do *not* change over time, then the species does not change. This is why there are species, like sharks or crocodiles or coelacanths that appear to have NOT changed in millions of years … their conditions have not changed.
It is the very fact that the earth is a variable place that explains why evolution is so relentless. A single-celled cyanobacterium can evolve in particular conditions in the ocean, but once that niche is filled, there is no more room in that environment for more cyanobacteria … so new bacteria at the outer edges of that environment either die, or they adapt to a neighboring niche … nearby waters with a different temperature, different salinity, more sunlight/less sunlight, etc. … new conditions.
Or imagine a world dominated by large predatory dinosaurs, hit by a large asteroid about 65 million years ago. Conditions change. Sunlight is blocked. Plants die. Temperatures drop. Oxygen levels drop. So large animals do not survive well. The large dinosaurs go extinct. Bad for them. Great for the small rodent-like mammals. They flourish.
As for how complexity is possible … look at a snowflake. It is formed because an ice crystal is forming in freezing air that is constantly changing conditions as the snowflake is buffetted around in the atmosphere. Small changes in local conditions (temperature + humidity) change the way that new water molecules freeze onto the growing crystal. The result is the complex object we see as a snowflake.
Evolution is very much like that. Constant change under constantly changing conditions … over truly DEEP TIME.