Bio Lecture November 4
Darwin travelled in ship
He made observations
Began to notice on Galapagos islands
Massive upheaval in biology that
There are organisms that once existed that don’t exist anymore
Earth changed overtime.
Also plants and animals changed overtime
o 1 All species have such great potential fertility
o 2 Populations tend to remain stable in size
Their sizes don’t fluctuate. The resources they have to use to eat.
o 3 Environmental resources are limited
o 4 individuals of a population vary extensively in their characteristics
o 5 much of this variation is heritable
Flora and Fauna
No 2 animals are the same or identical.
From these observations he made inferences
In 1859 he published the origin of species
o Descent with modification, evolution
Heritable variations in individuals
Overproduction of offspring
Individuals well suited to the environment tend to leave more offspring
Over time favourable traits accumulate in the population
Can individuals evolve?
o No, you cant change their genetic material. Their genotype.
o But populations can change overtime. How many of different alleles are around
o Thus individuals don’t evolve, populations evolve.