Evolution ~ Pre-Lab Notes & Vocab.Scientific Theories are based on: 1. Evidence – serves to either support or counter a scientific theory or

hypothesis 2. Inferences – conclusions that follow logically from some form of direct

evidence

Pre-Darwinian Theory - too many to mention, but here are a couple…- The German philosopher Immanuel Kant (1724-1804) developed a concept

of descent that is relatively close to modern evolutionary thinking. Based on similarities between organisms, Kant speculated that they may have come from a single ancestral source.

- Jean-Baptiste Lamarck's (1744-1829) theory of evolution was a good try for his time, but has now been discredited by experimental evidence. His idea of the inheritance of acquired characteristics. This theory stated that an organism could pass on to its offspring any characteristics it had acquired in its lifetime. For example, if a man exercised and thus developed strong muscles, his offspring would then have strong muscles at birth.

I love Science Class & Rocket Ships

Modern Evolutionary Theory – “Darwinism”

• Based on the studies of Charles Darwin and his published works starting with the 1859 “Origin of Species”

• Terms commonly associated with modern evolutionary theory:

- Adaptation - Variation

- Population - Species

- Natural Selection - Mutation

Adaptation

• Changes in an organism's physiological structure or function or habits that allow it to survive in new surroundings.

Population

• A group of organisms occupying a particular space; the number of living creatures in a designated area.

Natural Selection

• process in which species that are best adapted to their environments will survive

Species

• A group of individuals which can successfully breed with each other to produce offspring which can still breed with each other.

• A group of individuals having a common origin and a continuous breeding system.

Variation

• differences within a species

Mutation

• Any heritable change brought about by an alteration in the genetic material.

Speciation

• http://evolution.berkeley.edu/evosite/evo101/VSpeciation.shtml