What is the strict scientific definition of evolution?
A genetic change over time, specifically a change in allele frequencies within a population
What are the three pre-conditions required for evolution by natural selection as outlined by Darwin?
Heritable characters, variation in characters between individuals, and differential fitness between individuals
Natural selection operates on what?
phenotypes, not genotypes
What is the significance of the fossil Tiktaalik roseae
It is a key transitional fossil, or ‘missing link’ between fish and land-dwelling tetrapods
Why is the path of the left recurrent laryngeal nerve considered an example of ‘bad design’?
Because it takes a long detour from the brain, down around the aorta in the chest and back up to the larynx, when a direct path would be much shorter
In giraffes, how much longer than necessary is the left recurrent laryngeal nerve?
Approx. 5 metres too long
What is the evolutionary explanation for the laryngeal nerve’s path?
It’s a historical legacy from fish-like ancestors
What is the term for a remnant of an organ or structure that had a function in an early ancestor?
A vestige or a vestigial structure
What is the plica semilunaris in the human eye considered a remnant of?
Our repitilian past (a third eyelid or nictitating membrane)
Why are the muscles attached to the human outer ear considered vestigial
They can no longer produce significant movement to help locate sounds, unlike in many other mammals
What is the function of piloerection (goosebumps) in our furry mammal relatives when they are cold?
The raised hairs increase the space for insulation, helping them to stay warm.
What does the human tailbone (coccyx) represent?
It is the fused vertebrae that are what’s left of our ancestors’ tails.
Who is credited with the idea of ‘Evolution by acquired characters’
Jean-Baptiste Lamarck
Charles Darwin’s two great accomplishments were establishing the fact of evolution and proposing a theory to explain its mechanism, called _____.
Natural selection
For how long did trilobites exist, showing clear signs of evolutionary change over that period?
They lived for 280 million years.
The fossil Pakicetus is an early ancestor in the evolution of what modern animal group?
Whales.
What does the statement ‘Natural selection “tinkers”, it doesn’t “design”’ mean?
It means natural selection works by modifying existing structures and pathways, rather than creating perfect solutions from scratch.
What does the lecture identify as ‘the only consistent force leading to adaptations’?
Natural selectiono
In what type of rock sediments did Neil Shubin’s team search for Tiktaalik, based on predictive science?
Freshwater sediments around 375 million years old.
In the giraffe dissection video, the recurrent laryngeal nerve is shown to be a branch of what larger nerve?
The vagus nerve.
The evolutionary process by which one species divides and changes into new species is called _____.
speciation
Who famously stated, “Nothing in biology makes sense except in the light of evolution”?
Theodosius Dobzhansky.
Which French scientist is credited with establishing the concept that species become extinct?
Georges Cuvier (1769-1832).
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evidence for evolution45
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origin of species61
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speciation54
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fitness61
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genomes43
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human evolution50
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microevolution44
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more evidence for evolution53
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introduction to eukaryotic genetics52
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mitosis and meiosis27
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mendel's laws and beyond55
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gene interactions and epigenetics47
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gene interactions and epigenetics 246
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sex determination and sex linkage0
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gene mapping29
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human genetics0
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chromosome abnormalities / cytoplasmic inheritance0
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complex traits0
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what is developmental biology0
