Evolution Flashcards
(23 cards)
Evolution
Process of biological change. How modern organisms have descended from ancient organisms.
Macroevolution
Large scale changes that happen over a long period of time
Microevolution
Small changes that happen over a smaller period of time
All living organisms have…?
Use DNA as genetic material, very similar genetic codes, use the same process of transcription and translation, and use the same amino acids.
Developmental Similarities
Mature forms come from similar embryonic tissues, early forms look similar, and similarities in early development imply similar genes
Anatomical Evidence
Sharing structural similarities, but have different functions
Vestigial Structures
Evolutionary leftovers that lose function. Able to be observed for evidence of evolution.
Fossils
Preserved remains of an organism usually found in a sedimentary rock.
Geologic Time Scale
System of chronological dating that relates rock layers (geologic strata) to time.
Phylogenetic Trees
Diagram that represents evolutionary relationships between organisms.
Biogeography
Global distribution of organisms. Distributions follow patterns that are explained by evolution from common ancestors and plate tectonics.
Direct Evidence
We can observe small scaled evolution in organisms with short life cycles.
Natural Selection
A mechanism by which individuals that have inherited beneficial adaptations show differential reproductive success.
Fitness
An individual’s ability to survive and reproduce in its specific environment.
Artificial Selection
Us humans breeding organisms in a certain way in order to get the traits we want.
Variation (Natural Selection)
Differences in individuals’ traits, natural variation occurs in populations.
Overproduction (Natural Selection)
More offspring are produced than can survive.
Competition (Natural Selection)
Individuals must compete for resources and some individuals will outcompete others.
Adaptation (Natural Selection)
Beneficial traits become more common in the population over time as individuals with those characteristics survive better and reproduce more often.
Normal Distribution (Natural Selection Type)
Shows the data arrangement where most values fall in the middle of the data set.
It is bell-shaped and symmetrical.
Stabilizing Selection (Natural Selection Type)
Intermediate phenotypes are selected over extreme phenotypes.
Narrows the bell curve.
Directional Selection (Natural Selection Type)
One extreme phenotype is selected over all the other phenotypes.
Shifts the bell curve toward the favored extreme.
Disruptive Selection (Natural Selection Type)
Both extreme phenotypes are more fit than the intermediate phenotype.
Makes multiple peaks in the bell curve.
