S Flashcards
(26 cards)
What are the 3 types of adaptations?
Physiological, Structural, Behavioural
Give an example of structural adaptation.
Camouflage or mimicry (like a stick insect)
Example: A stick insect’s ability to blend in with its surroundings.
Difference between variation and adaptation?
Variation = individual differences; Adaptation = inherited trait that improves survival
What is natural selection?
Process where organisms better suited to the environment survive and reproduce
What does ‘fitness’ mean in evolution?
The ability to survive and reproduce
What’s the difference between natural and artificial selection?
Natural = environment selects; Artificial = humans select traits
What’s the founder effect?
When a new population is started by a few individuals, limiting genetic diversity
What’s the bottleneck effect?
A sharp reduction in population size reduces genetic diversity
Give 2 pre-zygotic reproductive barriers.
Temporal isolation, mechanical isolation
Give 2 post-zygotic reproductive barriers.
Hybrid sterility, hybrid inviability
Difference between homologous and analogous structures?
Homologous = same origin, different function; Analogous = different origin, same function
Example of directional selection?
Dark-colored peppered moths becoming more common during industrial revolution
Example: The increase in dark-colored moths due to pollution.
What is adaptive radiation?
One species evolves into many different forms (e.g., Darwin’s finches)
Example: Darwin’s finches adapting to different food sources.
What are the 5 sources of evidence for evolution?
Fossils, biogeography, anatomy, embryology, DNA
What is gene flow?
Movement of alleles between populations due to migration
What is an evolutionary advantage?
Given a species, a specific feature may provide an evolutionary advantage by increasing chances of survival and reproduction.
Example: Zebra stripes may confuse predators when in groups by creating a motion blur.
What are selective pressures on a population?
Selective pressures like climate, predators, or food availability influence which individuals survive and reproduce.
Example: In a cold environment, animals with thicker fur may survive better.
How does evolution happen according to the theory of evolution by natural selection?
Individuals with advantageous traits are more likely to survive and pass those traits to offspring, leading to evolution over generations.
What is Lamarck’s view on evolution?
Lamarck believed that giraffes stretched their necks to reach food, and this acquired trait was passed to offspring.
What is Darwin’s view on evolution?
Darwin believed that giraffes with naturally longer necks could reach more food and survived better, passing on the trait.
List 5 human activities that cause habitat fragmentation.
- Deforestation
- Urban development
- Pollution
- Agriculture
- Climate change
These activities can isolate populations and lead to new species forming.
What are pre-zygotic barriers?
Pre-zygotic barriers prevent fertilization, such as behavioral isolation and mechanical incompatibility.
What are post-zygotic barriers?
Post-zygotic barriers prevent hybrid offspring from surviving or reproducing, such as hybrid sterility like mules.
