Unit 1-2 Flashcards
(21 cards)
What are the 3 conditions necessary for natural selection to occur?
1) Variation in phenotypes; 2) Variation affects reproductive success; 3) Variation is heritable.
What did Peter and Rosemary Grant discover about finches on Daphne Major?
Beak depth changes year to year due to environmental conditions, showing natural selection in action.
What is industrial melanism?
The phenomenon where darker individuals become more common due to industrial pollution.
What caused the color shift in peppered moths during the Industrial Revolution?
Dark-colored moths had better camouflage on soot-darkened trees, avoiding bird predation.
How does artificial selection differ from natural selection?
Artificial selection is human-directed, selecting specific traits for breeding.
Give an example of artificial selection in the lab.
Fruit flies were selected for increased bristle number, which quadrupled over generations.
What does domestication of animals like dogs and foxes demonstrate?
Human-imposed selection can lead to behavioral and physical changes, sometimes unintentionally.
What are fossils?
Preserved remains or impressions of once-living organisms, often found in sedimentary rock.
What are the three steps necessary for fossil formation?
1) Burial in sediment; 2) Mineralization of tissue; 3) Sediment hardens into rock.
What is Archaeopteryx and why is it important?
It is an intermediate fossil showing traits of both dinosaurs and birds.
What does the fossil record show about horse evolution?
Transition from small, forest-dwelling animals to large, grassland-adapted species.
What are homologous structures?
Anatomically similar structures derived from a common ancestor, but with different functions.
How does embryology support evolution?
Vertebrate embryos show similar features early in development, such as pharyngeal pouches.
What are vestigial structures?
Organs or structures with no current function but present due to ancestral traits (e.g., human ear muscles).
What are pseudogenes?
Nonfunctional gene remnants from ancestors (e.g., hemoglobin gene in icefish).
What is convergent evolution?
Unrelated species evolve similar traits due to similar environmental pressures (e.g., dolphins and sharks).
What is biogeography?
The study of the distribution of species and how it supports evolutionary history.
How do island species support evolution?
They resemble nearby continental species and often evolve into unique forms.
How do scientists respond to the claim that evolution is ‘just a theory’?
In science, a theory is a well-supported explanation, like the theory of gravity or germ theory.
What refutes the idea that there are no fossil intermediates?
Numerous transitional fossils have been discovered, like Tiktaalik and early whale ancestors.
What is the scientific response to ‘irreducible complexity’?
Complex systems can evolve gradually, with each stage functional and beneficial.
