Module 44 Terms - Evidence of Common Ancestry and Evolution

Question 1

Morphological homologies

Answer 1

Anatomical traits that were present in a common ancestor and retained over time; similarities based on shared ancestry that are structural

Question 2

Molecular clock

Answer 2

The correlation between the time for which two species have been evolutionarily separated and the amount of genetic divergence between them

Question 3

Vestigial structures

Answer 3

Traits that were once useful and functional but are no longer and so tend to be reduced in size or function

Question 4

Fossil

Answer 4

The remains of once-living organisms

Question 5

Radiometric dating

Answer 5

Using the radioactive decay of an isotope to date geologic materials, such as fossils. Scientists measure the amount of an isotope in a sample, then compare it to the amount of the isotope in a different sample of known age to estimate the age of the original sample

Question 6

Half-life

Answer 6

The time it takes for an amount of substance to reach half its original value

Question 7

Invasive species

Answer 7

Non-native species that become established in new ecosystems

Question 8

What are three homologous traits shared by all eukaryotes?

Answer 8

Having cells with a nucleus, a cell membrane, mitochondria, and membrane-bound organelles