ARE THESE ALL BEARS?

WHICH ONES ARE MORE CLOSELY RELATED?

Evolutionary Family Trees• phylogeny - the evolutionary history of a

species• comparative phylogeny - comparing two or

more species and their evolutionary history• bioinformatics – applying mathematics and

computer sciences to analyze biological data (particularly molecular biology – ex. nucleic acids and proteins)

• You will use bioinformatic tools to analyze the evolutionary relationships among different animals.

rRNA• Ribosomal RNA (rRNA) makes up part of ribosomes.• Recall, ribosomes are where proteins are made and

all cells have them.• Some of the genes that make rRNA are found in

mitochondrial DNA.• Mitochondrial DNA is only inherited from the mother

because the sperm does not contribute its mitochondria to the egg.

• One of the rRNA mitochondrial genes in mammals is 12S rRNA.

• 12S rRNA is a very useful gene to study family trees.

How do genes help make family trees?

• Gene sequences (ex. ATGGCGTACCTTACGTT….) can be compared between different individuals as well as different species.

• The more similar the gene sequence, the more closely related to organisms are.

• The degree of similarity found between gene sequences is used to show how closely related organisms are and to show that relationship

What does the bear family tree look like?