Evolution Week 1 Flashcards
Does evolution occur in a single individual?
No, in populations over time.
Define biological evolution.
Any change in the inherited traits of a population that occurs from one generation to the next.
Define homology.
Characteristics shared among related individuals because of common ancestry.
Define synapomorphy.
A derived form of a trait that is shared by a group of related species.
Define phylogeny.
Evolutionary history of a lineage or a visual representation of the evolutionary history of populations, genes or species.
List 3 synapomorphies whales share with other mammals.
Mammary glands, 3 middle ear bones and hair (in developing embryos).
How did the similarities between fish and whales occur?
Convergent evolution.
Do modern cetaceans have different teeth than most land mammlas?
Yes.
What two synapomorphies do fossils whales share with modern cetaceans?
Ectotympanic bones with a thick and dense inner wall and a long vertebral column.
What 3 synapomorphies do fossils whales not share with modern cetaceans?
Teeth similar to Durodon, eyes sat on top of head and thin legs.
What are some independent lines of evidence document the transition from land to water?
Isotopic analysis of fossil teeth, fossil analysis of hindlimb loss and embryonic analysis linked to gene expression.
Terrestrial animals drink ______ and marine animals drink ______.
freshwater, seawater
What kind of ratio does seawater have?
O18/O16
Is the O18/O16 ratio higher in seawater or freshwater?
Seawater
What are other lines of research provide more clues about whale evolution?
Loss of teeth in baleen whales, evolution of brain size and complexity and whale diversity over evolutionary time.
