Chapter 25, Evolution of Life Flashcards
What are the four groups of eukaryotes we will study?
Protists, Fungi, plants, and animals
When was the earth formed?
4.6 BYO
Describe the bias in the fossil record
Not all species are represented equally, there is bias toward those that existed for a long time, were abundant and widespread, and had hard parts such as shells or skeletons
Describe radiometric dating
A method used to date fossils using the characteristic rate of decay (half-life) of a parent isotope to its daughter
How do we date fossils younger than 75,000 years?
The half-life of C-14
How do we date fossils older than 75,000 years?
Isotopes like U-238 are used to date the volcanic rock layers above and below the fossil
What are the three most recent eras?
Paleozoic, Mesozoic, Cenozoic
What marks the start of the 1st era?
Cambrian explosion-> Paleozoic
What was the name of the first prokaryotes? Describe them. When did they appear?
Stromatolites, bacterial mats that lived during the Archaean
What was the first eukaryotic organism? When was it?
Red algae, Proterozoic
When did the first multicellular eukaryotes appear? What were they?
Proterozoic, sponges and cnidarians
When was the age of the dinosaurs?
Mesozoic
When was the age of the mammals?
Cenozoic
When did atmospheric oxygen first start to rise? Who produced it? What was its effect on the life already present?
Archaean, cyanobacteria, killed many of the prokaryotes but some others used it for cellular respiration
When was land colonized? Who colonized it?
Start of Phanerozoic, arthropods (insects)