Unit 8 Changes Through Time Flashcards
Species that are closely related have more ____ in common
DNA
What is a diagram that shows how closely related different subspecies are?
Phylogenetic tree
Distinct populations within a species are called?
Subspecies
Which vertebrates are most closely related to rodents and rabbits?
Primates
Which vertebrates are most distantly related to crocodiles?
Sharks
Crocodiles and birds share a more recent common _____? They have more _____ in common.
- Ancestor
- DNA
How do subspecies acquire unique variations?
Mutations and genetic recombination
What is an adaptation?
A characteristic that helps an organism survive and reproduce
How are extravagant feathers an adaptation?
They increase the chances of reproduction
Adaptations are dependent on the organisms ______?
Environment
Give an example of an adaptation
Fins help a fish swim away from predators
What is natural selection?
Organisms that are better adapted to their environment are more likely to survive and reproduce
Name and describe 3 factors that are necessary for natural selection to occur
1) Overproduction: more offspring are produced than there is room for
2) Variation: offspring have differences
3) Competition: Individuals must compete for resources
Who first wrote about natural selection?
Charles Darwin
If genotype ratios are not in equilibrium, then what is happening in the population?
EvolutionTw
Two populations of a species may speciate when they do not _____ together
Reproduce
List 3 situations which may prevent members of a species from reproducing together
- Failure to recognize mating calls
- Mating at different times of day
- Geographic isolation - physically separated
Give 3 examples of specides which have recently separated into two (or more) species
- Meadowlarks (Eastern and Western)
- Fruit flies
- Squirrels (Abert’s and Kaibab)
- Grey fox (gray fox and island fox)
What is a fossil
A trace of a long dead organism
Describe 3 ways fossils may form
- Burial in sediment
- stuck in a tar pit
- caught in hardened tree sap (Amber)
What is the most common way for a fossil to form/?
burial in sediment
What kind of environment produces the most fossils?
oceans and lakes where sediment rapidly accumulates
What was the time before Paleozoic era known as?
Precambrian
What geologic era had mammals as the predominant fossil type?
Cenozoic
