ECHS Evolution & Diversity Notes

A comprehensive set of flashcards covering key concepts in evolution and diversity as discussed in the lecture notes.

What do fossils reveal about ancient life?

They reveal the structure of the organism, its environment, the way it lived, and that it is extinct.

What kind of rock are most fossils preserved in?

Sedimentary rock.

Where are the oldest fossils found?

Oldest fossils are found on the ocean bottoms as sand, silt, clay, and lime settle over time.

What is the difference between relative dating and radiometric dating?

Relative dating determines the age of fossils based on their position in sedimentary rock, while radiometric dating measures the decay of radioactive isotopes to determine age.

What is the purpose of using index fossils?

Index fossils are used to establish and compare the relative ages of rock layers and the fossils they contain.

What is half-life in radiometric dating?

The time required for half of the radioactive atoms in a sample to decay.

What is the geologic time scale?

A timeline of Earth's history.

What is the Cambrian Explosion?

A time period where there was a huge increase in biodiversity.

What are mass extinctions?

Events during which many species became extinct in a relatively short period of time.

How many mass extinctions have occurred?

Five mass extinctions.

What is the significance of Miller and Urey's experiment?

It simulated the origin of life, suggesting that simple compounds could combine to form organic compounds like amino acids.

What is endosymbiotic theory?

It proposes that eukaryotic cells formed from prokaryotic cells engulfing each other.

What is taxonomy?

The science of naming and classifying organisms.

What is binomial nomenclature?

A formal two-part naming system for species.

What two taxa make up the scientific name?

Genus and species.

What is a dichotomous key?

A set of paired statements used to identify organisms.

What are the eight taxa from broadest to most specific?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What is the goal of modern evolutionary classification?

To group species into larger categories that reflect evolutionary relationships.

What are cladograms?

Phylogenetic trees that show the evolutionary history of derived characteristics.

What are homologous structures?

Inherited from a common ancestor with similar structures but different functions.

What is a population in biology?

A group of individuals of the same species that mate and produce offspring.

What are mutations in genetic variation?

Any change in genetic material.

What is natural selection?

The process where organisms with favorable variations survive and reproduce.

What is common descent?

The principle that all species, living and extinct, are descended from ancient common ancestors.

How do DNA sequences relate to classification?

More derived characters two species share, the more recently they shared a common ancestor.

What are advantages of sexual reproduction in terms of genetic variation?

It allows for genetic recombination and increases diversity.