12 - a brief history of life

12 - a brief history of life - Biology 325H Brief history...

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

View Full Document Right Arrow Icon
Biology 325H Brief history of life on Earth 2/13/08 The next section of our course has two main goals. One goal is to continue with the theme of biological evolution, looking at ways in which organisms have adapted to improve their rates of survival and/or reproduction under particular environmental conditions. As we examine this phenomenon, our second goal will be to gain an appreciation of the interrelationship between structure (anatomy) and function (physiology). Consider your brain, an organ whose extraordinarily complex arrangement of synaptic connections is responsible for your many innate behaviors ( e.g. shivering; sneezing; coughing) and also your ability to learn new skills ( e.g. piano; chess; math). As with most biological traits, the primary reason why any living organism performs certain tasks efficiently is that its ancestors became adapted to those tasks – or something similar – through a process of natural selection. In the case of your brain, it didn't evolve its fantastic learning capabilities to play chess, but rather to efficiently hunt and grow food while making smart decisions within the context of the social group. Over the next three lectures we will examine some of the key events in the evolution of life on Earth from this viewpoint. Today we will look very broadly at major events in the evolution of cells and the origin of multicellularity. In the following lectures we will look more closely at the evolution of particular groups of organisms. Learning goals: 1. What are the three ‘domains’ of life on Earth? What basic features of molecular biology are shared by all three groups? How can we use parsimony to infer the traits of the last common ancestor? 2. Living organisms need a source of carbon and a source of energy. What are the different ways in which living organisms can obtain each of these requirements? Learn and be able to apply Purves’s Table 27.2. 3. Appreciate that the chemical composition of Earth's atmosphere has changed greatly over the last 4 billion years, and that life has both been responsible for and had to adapt to some of those changes. What biochemical process was responsible for the increase in atmospheric O 2 ? How did cells adapt to increased prevalence of this highly reactive and therefore potentially toxic molecule?
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 05/14/2008 for the course BIO 325H taught by Professor Staff during the Spring '08 term at University of Texas at Austin.

Page1 / 8

12 - a brief history of life - Biology 325H Brief history...

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