Evidence for Evolution

Describe the relation fo all living things with DNA

All living things have the same DNA code, adding to hypothesis that all have common ancestor. The sequence of bases in DNA of living things varies.

What causes gain and loss of genes

New genes gained by mutation, others lost by natural selection, genetic drift or some other process.

What # of differences in DNA between species indicates:

Species more distantly related have more differences in DNA, whereas species more closely related share greater portion of their DNA.

define comparative genomics:

comparison of genome sequences of different species

what does comparative genomics do?

It helps identify genes that are preserved among species, as well as genes that give each organism its unique characteristics.

What is a genome?

complete set of DNA in each cell of an organism

what is DNA hybridisation

technique measuring degree of genetic similarity between DNA sequences

Explain the process used for DNA Hybridisation:

DNA strands to be compared are mixed, incubated and allowed to reform as hybrid double-stranded DNA. DNA unzips at 94ᵒC. Hybridised sequences with a high degree of similarity will bind more firmly, and therefore will require more energy (in the form of heat) to separate them. [If more closely related species, unzip at 80ᵒC]