Chapter !5 - Evolution and Genomic Change Code: KSI0014

<Index of Chapter 5>

Evolution is exploration

Industrial melanism and its reversal. (Moth example)

The two elements of exploration - variation from the current state of the system and change to a new one - occur at many levels from individual genomes to proteins to cells to ecosystems

A long-standing challenge of biology is to understand the relationships among these different levels of evolution.

 

Biological systematics

Study of the vast variety of living organisms requires that we organize what we observe and measure. 

We have to agree on what we call things. Biological taxonomy encompaseses identifying new life forms, deciding where they fit in, and assigning them a name

Biological nomenclature

Measurement of biological similarities and differences 

-In order ti develop a clear picture of the relationships between species, it's necessary to pick  a molecule that is changing at a reasonable rate. There must e enough change such that the signal does not sink below the noise level, but not too much change as to obscure common features. 

 

Homogoues and families

Products of evolution retain similarities. The similarities appear at many levels- related people, recently diverged species, tissues within an organism containing related cell types but varying protein expression patterns, amino acid sequences and structures of proteins and DNA sequences. 

To trace the course of evolution, we must quantitatively measure such similarities. There are many possible objects of such analysis. 

 

Pattern matching - the basic tool of bioinformatics

Sequence alignment

Definining the optimum alignment

Approximate methods for quick screening of databases

Pattern matching in three-dimensional structures

Evolution of protein sequences, structures, and functions

The effects of single-site mutations

Evolution of protein structure and function

Phylogeny

Phylogenetic trees

Clustering methods

Cladistic methods

The problem of varying rates of evolution

Batesiian methods

Short-circuiting evolution : Genetic engineering