10T2K© Evolution

Thing 1: What is evolution? Evolution is the changes in genotypes and phenotypes that occur over time in a population. Natural selection—the different abilities of organisms to survive and reproduce—is a major force of evolution.

Thing 2: The more closely related two organisms are, the more features they share Two cardinals: Most alike A cardinal and a robin: Less alike A bird and a lizard: Less alike A bird and a tree: Less alike A bird and a bacterium: Least alike

Cardinal Birds Robin Animals Lizard Eukaryotes Tree Alive This works when comparing their genes, too! Bacterium

Homologous structures show common ancestry!

Thing 3: Fossils provide information about life from the past Usually, we can learn about the structure of the organism Sometimes, we can learn about its lifestyle Sometimes, we can learn about its environment

Thing 4: Radioactivity is used to estimate the age of a fossil Radioactive carbon in some fossils can be measured to determine their age (up to 70,000 years). This is called carbon dating or absolute dating. For older fossils, the age of igneous rock layers near them can be determined by measuring other kinds of radioactivity. This is called relative dating.

Thing 5: Adaptations match form and function Just like the beaks of Darwin’s finches, the shape of other organisms relates to the organism’s environment or activities. Adaptive radiation describes how one species can evolve into several related species, each with its own specialization.

Darwin’s finches

Thing 6: Phylogenetic trees show how life changes over time

Thing 7: All life on Earth evolved from a common ancestor Because all living things have genes and structures in common (ribosomes, phospholipid bilayers, the genetic code, etc.), there was some common ancestor from which all life evolved.

Thing 8: Punctuated equilibrium is one theory about the rate of evolution From the fossil record, it appears that many species remained relatively unchanged for long periods of time followed by relatively short periods of rapid change. That is the theory of punctuated equilibrium.

Thing 9: A phenotype that is best fit for one environment might be unfit for another environment Fitness isn’t absolute. It’s an advantage for a polar bear to be white, but not for a grizzly bear.

Thing 10: Lamarck had an incorrect theory about evolution. Lamarck said that offspring inherit characteristics that their parents acquire during their lifetime. By that logic, we would all be born knowing how to drive.