BIO342 Evolutionary Biology Lecture 1
Evolution is a change in the frequency of an allele or genotype through time within a
allele - a unique copy of a gene
genotype - individuals that share th same set of alles at one more loci
population - group of interbreeding individuals
◦ population is the unit of evolution
◦ individuals cannot evolve
when a change in the frequency of alleles cause a change in the distribution of
phenotypic traits within a population we call this phenotypic evolution
a phenotypic trait is any characteristic of an organism i.e. Hair/eye colour,
height, weight, size, behaviour, physiological response, etc.
What is Evolutionary Biology?
evolutionary biology - scientific discipline that tests hypotheses proposed to
explain evolutionary processes and patterns associated with organic evolution
(i.e. the evolution of life)
Why is evolutionary biology important?
evolution explains the history and diversity of all life on earth
4.6 billion years ago, earth started as molten soup, no life at all
in the 1st billion years, earth cooled
as water appeared (by 4 bya) first signs of life appeared, molecules that self
replicated - amino acids
amino acids gave rise to more complex life, similar to RNA
◦ self replicate and make copies of itself
◦ more resistant to changes in the environment
single common ancestor (4 bya) gave rise to all the organisms you see on earth
Climate change: can populations adapt?
changing precipitation and atmosphere on earth
industrial evolution, manufacturing ◦ CO2 bouncing up to 300 ppm then 50 years ago, sky rocket
◦ increase in temperature, length of growing season, increase about 10 days
longer on average
changed the way we see the world around us
glacier receding due to human influence
profound effect on life on