early ideas on evolution Flashcards
What is biogeography?
The study of geographical patterns in the distribution of living and fossilized species as evidence for evolution.
Give examples of species that show biogeographical patterns.
Beaver & Muskrat (North America) vs. Capybara & Coypu (South America)
Ostrich (Africa), Emu (Australia), Rhea (South America)
What does “Species Vary Globally” mean?
Distantly related species living in similar habitats in different parts of the world often look and act similarly
What does “Species Vary Locally” mean?
Related animal species in different habitats within the same area evolve different traits best suited for their environment (e.g., Galapagos tortoises).
How did finches in the Galapagos provide evidence for evolution?
Different finch species had different beak structures adapted to different food sources, indicating adaptation from a common ancestor
How did Darwin’s observations support the idea that environments influence traits?
Species in different environments had distinct traits that helped them survive, such as modified cactus leaves in dry climates
How does Pangea support evolutionary evidence?
Northern and Southern animals are more closely related to others within their hemisphere, showing patterns of species distribution from continental drift.
What was Darwin’s hypothesis about species on remote oceanic islands?
Species arrived by air or water and then evolved into new species over time
How did Hawaii support Darwin’s hypothesis?
Hawaii, being far from any landmass, had no native mammals or amphibians, reinforcing the idea that only certain species could populate isolated islands.
What are homologous structures?
Structures that are similar in different organisms but serve different functions, inherited from a common ancestor.
Give an example of homologous structures.
Forelimbs of mammals used for different functions, such as a whale’s flipper and a bat’s wing.
What are analogous structures?
Structures that serve similar functions but evolved independently (e.g., wings in birds and insects).
What are vestigial structures?
Rudimentary, nonfunctional structures that were functional in ancestral species (e.g., human appendix).
How does competition within populations provide evidence for evolution?
Due to limited resources, not all offspring survive, leading to natural selection.
What did Thomas Malthus contribute to Darwin’s understanding of evolution?
He showed that populations are limited by their environment, influencing Darwin’s concept of natural selection.
How does comparative cytology support evolution?
Organelles are structurally and functionally similar across species, indicating common ancestr
How does comparative biochemistry support evolution?
Similar proteins and enzymes in different organisms suggest shared genetic origins.
How does DNA provide evidence for evolution?
Similar DNA patterns across species indicate inheritance from a common ancestor.
What percentage of DNA differs between humans and chimpanzees?
1.2%, with more differences found in the Y chromosome than expected.
What are the four nitrogenous bases shared by all living organisms?
A: Adenine, Guanine, Cytosine, and Thymine.
