BIMM 120 Lecture13_ReadingGuide.051211

BIMM 120 Lecture13_ReadingGuide.051211 - Lecture 13...

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

View Full Document Right Arrow Icon
Lecture 13 – BIMM120.SP11 LECTURE 13 – May 12, 2011 (BLACK = this lecture / BLUE = different lecture / RED = not covered in lecture ) Chapter 14 – Microbial Evolution and Systematics (pp. 367-374; 390-393) I. Early Earth and the Origin and Diversification of Life 14.1 Formation and Early History of Earth Origin and Diversification of Life o The theme that unifies all of biology is evolution Origin of Earth o Earth is thought to have formed about 4.5 billion years ago, based on data from slowly decaying radioactive isotopes Evidence for Microbial Life on Early Earth o Some ancient rocks contain what appear to be bacteria-like microfossils, typically as simple rods or cocci o In rocks of 3.5 billion years old or younger, stromatolites are abundant. Stromatolites are fossilized microbial mats consisting of layers of filamentous prokaryotes and trapped sediment 14.2 Origin of Cellular Life Surface Origin Hypothesis o One hypothesis for the origin of life is that the first membrane-enclosed, self- replicating cells arose out of a primordial soup that was rich in organic and inorganic compounds in a “warm little pond” o This hypothesis is unlikely as the surface conditions of early Earth would have been too hostile for life Subsurface Origin Hypothesis o An alternative hypothesis is that life originated at hydrothermal springs on the ocean floor, well below Earth’s surface. Conditions here would have been much less hostile and more stable
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 03/06/2012 for the course BIMM 120 taught by Professor Larsen during the Spring '08 term at UCSD.

Page1 / 3

BIMM 120 Lecture13_ReadingGuide.051211 - Lecture 13...

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