AP Bio Chapter 22 Part 4 Flashcards
Genetic drift is
Random
The traits that are adapted are typically
Better suited for the environment
Gene flow is
Immigration/emigration
When must traits pop up to be passed on?
Before reproduction
Theory
A major unifying framework, supported by all evidence currently known
Describe layers of fossils
Generally, layers of sedimentary rock contain fossils
New layers cover older ones, creating a record over time (fossil record)
How can fossils be dated
Relative dating, using layers, or radioactive decay, absolute dating
What does the fossil record show
A succession of organisms have populated earth throughout a long period of time (old earth)
Transitional fossils
Show evolutionary links between groups of organisms
Tiktaalik
A transition fossil between fish and amphibians
Archaeopteryx
Dinosaurs to birds
Homologous structures
Similarities in characteristics resulting from common ancestry
Similar structure, similar development, different functions
Evidence of close evolutionary relationship (recent common ancestor)
Why did the whales pelvis shrink
It was a hindrance to it until it shrink in its body, so it didn’t need to shrink anymore
Phylogeny
How things are related (evolutionary family history)
Analogous structures
Similarities in adaptations resulting from similar evolutionary pressures
Different structures, different development, similar functions
Evidence of convergent evolution
Divergent evolution
Go in different directions
Vestigial organs
Structures that serve little or no function
Remnant of structures that were functional in ancestral species
Where do deleterious mutations accumulate
Genes for non critical structures without reducing fitness
Comparative embryology
Similar embryological development in closely related species
All vertebrate embryos have similar structures at different stages of development
