Evolution Flashcards
What is evolution?
The accumulation of genetic changes within a population over time.
What is natural selection?
A process where inherited traits that improve survival and reproduction are preserved, while less favorable traits are eliminated.
What are the main sources of evidence for evolution?
Fossil record, biogeography, comparative anatomy, molecular biology, and developmental biology.
How does the fossil record support evolution?
It shows a chronological sequence of changes in organisms over time, including transitional species.
How does biogeography support evolution?
Geographic distribution of species reflects their evolutionary history and migration patterns.
What was Lamarck’s theory of evolution?
He proposed that traits acquired during an organism’s lifetime could be passed to offspring.
How does molecular biology support evolution?
DNA similarities between species indicate common ancestry.
Why was Lamarck’s theory later disproven?
The discovery of genetics showed that traits are inherited through DNA, not acquired characteristics.
What observations led Darwin to develop his theory of evolution?
Variation in traits, overproduction of offspring, limits on population growth, and differential reproductive success.
What is an adaptation?
A trait that improves survival and reproductive success in a given environment.
How did Galápagos finches provide evidence for natural selection?
Different species evolved distinct beak shapes suited to different food sources over millions of years.
What is speciation?
The evolution of a new species from an ancestral species.
What are the two main types of speciation?
Allopatric (geographic isolation) and sympatric (same location but different ecological or genetic factors).
How does reproductive isolation contribute to speciation?
It prevents gene flow between populations, leading to the formation of distinct species.
What are the two main types of reproductive isolation?
Pre-zygotic (before fertilization) and post-zygotic (after fertilization).
What are some examples of pre-zygotic isolation?
Temporal, habitat, behavioral, mechanical, and gametic isolation.
What are some examples of post-zygotic isolation?
Hybrid inviability and hybrid sterility (e.g., mules).
What is macroevolution?
Large-scale evolutionary changes, including the formation of new species and higher taxonomic groups.
What is punctuated equilibrium?
A model of evolution where species remain unchanged for long periods, followed by rapid evolutionary changes.
What is phyletic gradualism?
A model of evolution where species change gradually over long periods.
