Evolution Midterm Review

Evolution terms packet flashcards for biology midterm.

Species

A population whose members can interbreed and produce viable, fertile offspring.

Frequency FORMULA

# of something

————————— x 100

total number) x 100

Transitional Series

Evidence for evolution.

Homologous structures

Same structure, different function

Analogous structures

Different structure, similar function

Convergent Evolution

Unrelated organisms evolve separately from each other in similar environments and adopted to have similar structures/functions.

Speciation (Pattern of Macroevolution)

Occurs when populations of the same species are seperated, resulting in reduced gene flow, which over time allows the populations to become genetically distinct from one another.

Adaptive Radiation (Pattern of Macroevolution)

The evolution of how ancestral species, which were adapted to a particular way of life, into many diverse species in a different habitat.

Gradualism (Pattern of Macroevolution)

Gradual accumulation of small changes over a long period of time.

Punctuated Equilibrium (Pattern of Macroevolution)

Rapid bursts of change mixed with long periods of no change.

Vestigal Structures

Organs that serve no useful function in an organism

Embryology

Embryos of organisms with common ancestry often have similar embryonic development.

Biochemical Evidence

Almost all living organisms use the same basic biochemical molecules: DNA and Proteins. Can show a common ancestor.

Struggle for existence

Competition for resources

Natural Selection

A process where organisms with traits better suited to their environment are more likely to survive and reproduce, passing on those traits to their offspring, leading to evolution.

How is antibiotic resistant bacteria an example of natural selection?

Shows survival of the fittest.

What roles do selective pressure, variation, and heredity play in natural selection

Selective pressure chooses favorable traits, while heredity and variation determine which ones are passed down to offspring.

Descent with modification

Over time, natural selection produces organisms with different structures to suit their environment. Changes in gene frequency and species.

Survival of the Fittest

Competition among species and for resources

Geographic Isolation

• A physical barrier

• New species occur in different areas

Founder effect (Genetic Drift)

When a new population is started by only a few individuals.

Bottleneck Effect (Genetic Drift)

When a large population is drastically reduced by a disaster.

Lamrack’s Theory of Use and Disuse

The selective. use or disuse or organs leads to acquiring or losing certain traits during an organisms lifetime. These traits can be passed onto offspring.

FALSE !

Theory of Acquired Characteristics

If an organism changes during life in order to adapt to its environment, those changes are passed on to its offspring.

Adaptations

A trait that helps an organism be more suited to its environment.

Natural Variation

Variety of characteristics

Directional Selection

FOR: one extreme trait

AGAINST: the other extreme

Disruptive Selection

FOR: Both extremes

AGAINST: Moderate traits

Selective Selection

FOR: The moderate traits

AGAINST: Both extremes