Larson 5
letter from
            Charles Darwin to Alfred Russel Wallace
Darwin's book led to almost complete acceptance of evolution by the scientific community within 20 years
evolution was accepted, but Darwin's mechanism became increasingly controversial
--be careful here: it is crucial to see that there was controversy on the level of details but not on the level of the overall idea

two different ideas about evolution were catching on--some but not all scientists accepted both:

Descent with modification was widely accepted in just a few years and within 20 years no controversy remained among mainstream scientists in the English-speaking world: all had adopted it

The idea caught on so quickly because it met the needs of science

embryonic development
A great deal of research interest in the relationship between species and missing links

New Zealand was particularly unique because of its extreme isolation

one way to think about an ecosystem is as a series of niches--ecological opportunities
what fills these niches if the usual animals aren't there?
giant weta--half as big as a hand
giant weta
an insect that takes the ecological niche of a mouse--
unfortunately cats think them great entertainment

Another animal filling the niche of the mouse was the Stephens Island Wren

Stephens Island WrenA flightless songbird--one of only three flightless songbirds ever known and the world's smallest

the largest flightless birds, the moas, filled the niche of grazing animals
giant moa bigger than the
            hunter chasing it with a boomerang
All 11 species of Moa were hunted to extinction by the Maori in the 13th and 14th century.  They only laid one or two eggs at a time and took 10 years to grow to maturity so were wiped out easily.

"Second only in weight to the extinct elephant bird of Madagascar, the largest moa was the tallest bird on earth, with the top of its' back 6 feet above the ground" (source)

The largest Moa still weighed over 500 lbs.  They ate mostly bushes and the lower branches of trees.  Their beaks were strong

The Haast's eagle, with wingspan of 3 meters, preyed on the Moa and died out with it

Haasts eagle attaching

While evolution had become the basis of biology by the end of the century, natural selection was still controversial

Four alternative mechanisms for evolution, alternative theories to Darwinism (gradual random variation selected by natural selection):