Biology: Evolution

Study Notes

Evolution is the change in gene frequency in a population's gene pool over several generations.
Evolutionary change occurs within a population over many generations, not in individual organisms within their lifetime.
Evolution occurs in gene pools, not genomes.
There are two scales of evolution: microevolution (small scale, causing a change in allele frequency) and macroevolution (larger scale, leading to the creation of new species).

Charles Darwin was an English naturalist, biologist, and geologist who proposed the theory of natural selection as a mechanism for evolution.
He was born in 1809 in Shrewsbury, England, and initially studied medicine at Edinburgh University in Scotland.
Darwin's passion for natural history led him to focus on it instead of medicine, and he eventually embarked on a voyage aboard the HMS Beagle in 1831.
During the voyage, Darwin collected numerous samples of plants, animals, rocks, and fossils, which he sent back to England for further study.
Upon his return, Darwin's work led to groundbreaking scientific discoveries, including the understanding of fossil formation and the shaping of the Earth's surface.

The theory of natural selection states that individuals with traits best suited to their environment are more likely to survive and pass on their genes to the next generation.
This leads to the widespread adoption of such traits in a species and can eventually result in the development of a new species.
Darwin published his thoughts on evolution and natural selection in On the Origin of Species in 1859.
The book was popular and controversial, suggesting that the planet was much older than commonly believed at the time.

Darwin's two main ideas about the change in species over time are the mechanism of natural selection and the concept of common descent.
The concept of common descent proposes that all organisms alive on Earth today originated from a common ancestor.