Explore Evolution Chapters 5 – 6

Embryology:
What did Darwin consider the two main points embryology established?
1. First, it established that organisms had evolved from a common ancestor.
2. Second, observable similarities in different embryos revealed what the ancestors to these organisms would have looked like.

What did Ernst Haeckel contribute to embryology?
Drew the embryos of various species at early, middle, and late stages.

What is Haeckel’s “Biogenic Law”?
Ontogeny recapitulates phylogeny. (Embryos step-by-step process of development repeats the evolutionary history of the species)

What is different about Darwin & Haeckel’s view of embryology and the modern neo-Darwinist view?
Neo-Darwinists no longer think that embryos reveal the adult form of their evolutionary ancestors.

Embryology Reply:
Adam Sedgwick’s (1894) challenged which two of Darwin’s claims?
1. Vertebrate embryos more alike than vertebrate adults.
2. The younger the embryos, the greater the resemblance.
Adam Sedgwick said that he could distinguish a duck from a chicken embryo on the 2nd day.

What were wrong with Haeckel’s drawings?
1. Look radically different from the actual photographs of the embryos.
2. He edited the drawings to make them appear more similar.
3. Left out the earliest stages of development.

What did Michael Richardson do in 1997?
Compared Haeckel’s drawings to actual photographs of the embryos and showed everyone how fake they were.

Stephen Jay Gould wrote “We do, I think, have the right to be both astonished and ashamed by the century of mindless recycling that has led to the persistence of these drawings in a large number, if not a majority, of modern textbooks.”

What does Biogeography study?
The distribution of populations and species across the globe.

Why are Galapagos animals similar to animals in South America?
Probably came from South America because it is the closest continent.

Why are Galapagos animals different from animals in South America?
After separation from South America, they would have adapted to their own environment differently from those in South America.

What is the best explanation for the diversity of animals and plants found at the Galapagos Islands?
The Galapagos animals adapted in different ways after arriving at their new environments.

Why are marsupials found in Australia?
Evolved on Gondwanaland, Continents split up S. America, Antarctica, & Australia joined for the longest period.

Biogeography Reply:
Fixity of species
No change in anatomy of a species; No change in place (migration)

Which definition of evolution does Galapagos mockingbird radiation support?
Change Over Time (Population Genetics)

Microevolution
tree doesnt start from one another

Macroevolution
one tree of life

Where are the oldest fossil marsupials found?
In China and North America

What did Georges Cuvier say about migration and adaptation?
Cuvier accepted that migration and adaptation would alter the features of species, but doubted that they could undergo unlimited change; did not accept that all species share a common ancestor.