huelsenbeck14notes - Lecture 14 Monday, April 6, 2009...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 14 Monday, April 6, 2009 Fossils are preserved remains or traces of living organisms. Fossils are found in sedimentary rocks: Fossilization is not random. Hard parts — teeth, bones, shells — are most likely to be fossilized. Only under very rare conditions are soft body parts fossilized. Taphonomy is discussed in the laboratory on macroevolution. Trace fossils preserve some behaviors: Footprints, tracks, burrows, and underground nests occasionally provide information about behavior, e. g. stride length, gait, etc. Some recent fossils can yield DNA for analysis: DNA, primarily mitochondrial DNA, has been extracted from many fossils. The current upper limit is roughly 100,000 years. Whether DNA can be extracted from a fossil depends on the conditions of preservation and storage. Heat and humidity degrade DNA rapidly. Claims of sequencing DNA extracted from older specimens, including ancient bacteria, leaves, dinosaurs, and insects in amber, are not valid. Relative and absolute dates can be estimated
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/13/2009 for the course BIO 1B taught by Professor Carlson,mischel,power during the Spring '07 term at University of California, Berkeley.

Page1 / 2

huelsenbeck14notes - Lecture 14 Monday, April 6, 2009...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online