Natural selection will only cause evolution if there is enough genetic variation in a population. Before the discovery of Mendelian genetics, one common hypothesis was blending inheritance. But with blending inheritance, genetic variance would be rapidly lost, making evolution by natural selection implausible.
Amazon Kindle Fire (2012) The Kindle Fire has a multitouch-capable 7-inch IPS display, a dual-core processor, and at 14.6 ounces, a pretty lightweight frame. The resolution on that screen is 1024 x 600. The battery is rated to last for eight hours of continuous reading or 7.5 hours of video playback (with WiFi switched off).
There are two storage options for the 7-inch Kindle Fire HD: 16GB for $199 or 32GB for $249. Opt for the smaller and you'll have about 12.6GB of space at your disposal, while the larger offers 26.9GB. Otherwise the two are identical, both using a 1.2GHz dual-core TI OMAP4460 processor.