Bio 16.4

Why is understanding mutations and the reshuffling of genes during sexual reproduction important to understanding how natural selection operates

Both processes together produce the heritable variation on which natural selection requires to operate

What patterns in biogeography provide support for Darwin's theory

Closely related species are different in slightly different climates, very distantly related organisms develop similarities in similar habitats

Why was one of Darwin's difficulties solved when the age of the Earth was discovered to be 4.5 billion years old

Darwin thought evolution by natural selection would take a long time to occur. After the age of the Earth was discovered to be quite old, that provided more than enough time for evolution to work

What originally was the problem with Darwin's theory of Evolution by Natural Selection

Depended on assumptions from other fields of science which did not have the knowledge or technology to test many of his hypotheses. (ex. Fields of genetics and molecular biology had not even been invented as fields of science)

Describe how embryology provides evidence of evolution in vertebrate animals

Developmental stages of embryos is very similar in all vertebrates. Same group of embryonic cells develop in same pattern and order to produce similar organs and tissues. Further evidence of common ancestor for all vertebrates.

What was Darwin's explanation for the different beak sizes for the Galapagos Finches

Each beak size and shape was selected for or against based on the types of food that the finches became adapted to eat. Large beaks eat large seeds. Narrow beaks pick insects off of leaves

What has been the verdict on Darwin's theory now that the branches of genetics and molecular biology have developed

Every scientific test they have run has supported Darwin's ideas

What did the research by Peter and Rosemary Grant on Galapagos finches discover

Finches with different sized beaks have better or worse chances of surviving changes in the environment. They documented that natural selection takes place frequently and sometimes rapidly

How would the study of genetics helped Darwin defend his theory of evolution by means of natural selection

He couldn't explain heredity since the science had not been discovered yet. The discoveries by Mendel, Watson and Crick and genomics have helped explain how traits are inherited between generations

Explain the difference between homologous structures and analogous structures

Homologous structures between different species are similar in structure and have a common ancestor. These structures are adapted for a different purpose. (ex. Human hand and dolphin flipper; same bones different function), Analogous structures have a common function but not similar structure. The structure was not shared with a common ancestor. (ex. Wing of bee and wing of bird)

What are vestigial structures AND provide TWO examples

Inherited structures from ancestors that do not have much to any function in the descendent/current species. Ex.) Hipbones in dolphins, wings of flightless birds, legs of 3-toed skink, tail in human embryo

How have more recent fossil finds helped support the theory of evolution by natural selection

Provided series of fossils of extinct ancestors that trace the evolution of modern species. Ex. Ancient and modern whale species)

What are Hox genes

The genes that determine all the head-to-tail body parts for each species of organism. Small changes to these genes have been studied to explain how different organisms have changed over time and have descended from a common ancestor

What is biogeography

The study of where species live now and where their ancestral species lived in the pas

In what way does the study of the cytochrome c protein in organisms provide evidence for evolution

Very similar versions are found in almost ALL living cells. Shows that molecules can show homology as well