Evolution (1) Flashcards
What are the 3 evolutionary principles?
- Natural selection.
- Sexual selection.
- Population genetics.
What are the evolutionary events? (2)
• Species.
• Speciation.
Evolution?
= descent with modification.
What do you mean by descent with modification?
Modification is seen in subsequent generations.
“Modification” in descent with modification?
= change in genetic material (allele/geneotype) due to mutations or genetic recombination.
Who/What evolves?
Populations.
“Descent” in descent with modification?
= subsequent generations.
How do we collect evidences of evolution? (2)
• Experimental data.
• Observational/Descriptive data.
How do we display evidences of evolution? (2)
• Cladograms.
• Character tables.
Who discovered this process called evolution? (2)
• Charles Darwin.
• Alfred Wallace.
Hypotheses that Darwin & Wallace presented? (2)
• Descent with modification.
• Natural selection.
Through what evolution principle do divergence & convergence happen?
Natural selection.
Convergence/convergent evolution?
= evolution where similar structures evolve independently across different groups.
Divergence/divergent evolution?
= evolution where groups diversify from a common ancestor.
Constituents of evolution/Fundamental questions in evolutionary biology? (2)
• Patterns.
• Processes.
Patterns of evolution?
= where evolutionary biologists often look at the history of life.
Questions asked under the history of life (patterns of evolution)? (3)
• What are the origins of life on Earth?
• What do we see in the evolution of traits in new species?
• Mass extinctions (of millions of species).
Processes of evolution?
= where evolutionary biologists often refer to the causes of evolution.
Questions under the causes of evolution (processes of evolution)? (3)
• What causes new species to arise?
• What are the causes behind trait changes through time?
• What are the causes of the differences in the rates of evolution?
Evolution over a short time scale attributes? (2)
• Short generation time.
• Time scale = hours, days, weeks.
Evolution over a long time scale attributes? (2)
• Long generation time.
• Time scale = years.
Result of long-scale evolution/evolution over a long time scale?
Leads to diversification.
Pokémon “evolution”?
= where Pokémon go through metamorphosis/a life cycle and don’t undergo evolution/don’t evolve.
Why do you say Pokémon go through metamorphosis?
Because they do not develop over time but instead change form/change morphology.
Contrast metamorphosis & evolution?
● Metamorphosis = transformation.
● Evolution = development.
Evidences of common ancestors? (5)
• Embryological evidence.
• Homologous structures.
• Vestigial structures.
• Biogeography.
• Biomolecules.
Cause of evolution?
Natural selection.
How is … the cause of evolution?
Evolution across populations requires populations to have survived over time. Therefore, NS is a cause of evolution as it has enabled & continues to enable populations to evolve through ensuring that they survive environmental pressures by their traits having fitness elements & through the ability of those traits to be passed on from generation to generation.
Evolution attributes? (3)
• Unifying theory in biology.
• Scientific fact explained by evolutionary theory (NS).
• Involves descent with modification.
Evolution breakdown? (2)
• Evolvere = to unfold/unroll.
• Therefore, evolution = change over time.
Evolutionary biology?
= multidisciplinary discipline which includes studies of behaviour, paleontology, etc.
Evolutionary biologists? (2)
• Charles Darwin.
• Anusuya Chinsamy.
Charles Darwin attributes? (3)
• First to provide evidence of evolution.
• Developed the Theory of natural selection.
• Collected & studied fossils and living specimens from all over the world.
Changes that evolutionary biologists may investigate? (3)
• Changes in morphology.
• Changes in genetic diversity.
• Change over time scales.
Long branchs of phylogenetic tree attributes? (2)
• “Slow” evolution.
• Evolution occurs over a long period of time.
Short branchs of phylogenetic tree attributes? (2)
• Rapid evolution.
• Evolution occurs over a short period time (bursts of evolution).
Eg of evolution over a short time scale?
Drug resistant bacteria.
Theory?
= based on ideas that are supported by evidence collected & experiments conducted.
Evidences for evolution? (2)
• Descent with modification.
• Natural selection.
Egs of animal groups Darwin studied? (3)
• Darwin’s finches.
• Beetles.
• Barnacles.
Where did life begin?
All life shares one common ancestor.
Eg of embryological evidence?
Comparison of fish, reptile, bird & human embryos.
Eg of biomolecules?
DNA humans share with chimpanzees & zebra fishes.
Eg of Homologous structures?
Comparison of arm in birds, bats, horse, human, turtles & seal where birds & bats use wings for flight, while turtles & seals use limbs for swimming.
Egs of Vestigial structures? (2)
• Extinct whale ankles.
• Coccyx in humans.
Homologous structures?
= similar physical features in organisms that share a common ancestor, but the features serve completely different functions.
Vestigial structures?
= structures that have no apparent function & appear to be residual parts from a past ancestor.
Eg of biogeography?
Location of the fossils of giant armadillos (North America), giant pangolins (Africa) & giant anteater (South America).
Egs of convergent evolution? (2)
• Aquatic organisms (Dolphin, Penguin, Ichthyosaur = similar body shape).
• Aerial organisms (Birds, Bats, Flying fish, Pterodactyls = wings for flight).
What is convergent evolution a result of?
Similar selective pressures in unrelated groups.
What is divergent a result of?
Different selective pressures in related groups.
Eg of divergent evolution?
Comparison between the Viceroy butterfly & Monarch butterfly.
