Evidence for Evolution

Describe how comparative genomics can show the relatedness of two species?


All living things use the same DNA code –Suggests that all living things came from a common ancestor”

As species drift apart, they will acquire more and more differences due to mutations, natural selection and genetic drift

Comparative genomics compares the genomic sequences (the complete set of DNA in each cell of an organism) of related organisms

  • We can use this to provide a percentage difference/similarity between two species through DNA sequencing will be used to determine the order of base pairs


Describe how endogenous retroviruses can show the relatedness of two species

Endogenous retroviruses are viral sequences that get inserted into particular, non-coding, parts of DNA

They are then able to be inherited in the same loci on the same chromosomes in all members of the species

If two species have ERV in the same loci it is indicative of a close relationship

Humans and chimps have 16 ERV’s at the same locations


Describe how protein sequences can show the relatedness of two species

Comparison of the amino acids that make up particular proteins

Ubiquitous proteins are proteins that a common on all species.

The more similarities the proteins have in their amino acid structure, the more closely related the species are.

  • Other examples include keratin, collagen, elastin etc.



Differentiate between mitochondrial and nuclear DNA in relation to inheritance

DNA found in the mitochondria that contains only 16500 base pairs

Inherited only from mother and prone to more substitution mutations at a higher rate

Can be used to map relatedness of individuals due to how many mutations have occurred

  • Has been used to trace movement of humans


Define bioinformatics and explain how it can be used to aid the understanding of evolution

Define:

A scientific discipline that collects, stores and analyses data relating to genetics and genomes.”

“As we are dealing with such huge amounts of data (human genome contains ~ 2.9 billion base pairs), the greatest difficulty comes with the speed at which it can be analysed.”

“Computer programs and algorithms are employed to make this process more efficient.”


Explan:

developments in the fields of comparative biochemistry (including DNA and protein sequences) and bioinformatics have enabled identification of further evidence for evolutionary relationships, which help refine existing models and theories