Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
42 Cards in this Set
- Front
- Back
Define natural selection |
The process by which certain individuals of a population have a genetic makeup which makes them more suited to their environment and allows them to be more reperductivley successfull |
|
What is VERA |
Variation |
|
What is considered in the variation stage of natural selection |
More offspring are produced than can survive. |
|
Give an example of variation |
The peppered moth lays more eggs than will survive and varies from dark to light in colour |
|
What is considered in the environmental pressure stage in natural selection |
Things can change that effect a species such as: |
|
Give an example of how environmental pressure can effect a species |
Peppered moth - A physical change to the environment as the trees become covered in black soot due to the industrial revolution, led the darker moths to better suit the environment |
|
What is considered in the reproduction stage of natural selection? |
Those organisms that compete most successfully will survive to breed and therefore pass on their genes to the next generation. |
|
Give an example of the reproduction for a species |
Peppered moth - the dark coloured moths were most successful, gene reproduced so offspring also had dark colour |
|
What is considered in the adaption stage of natural selection? |
This variation is now an adaption because it enables the organisms that posses it to cope with the selective pressures. This variation becomes dominant in the population. |
|
Give an example of the adaption of an organisms |
Pepperd moth - Dark coloured moth becomes dominant in the population since they are able to camouflage itself. |
|
Define isolation |
When a population becomes geographically isolated from another, becoming so different they are unable to interbreed and produce fertile offspring. |
|
Define divergent evolution |
Evolving from a common ancestor, the population becomes isolated, becoming different from eachother |
|
Give an example of divergent evolution |
The galapagos finches all evolved from a common ancestor (South american mainland) |
|
Define convergent evolution |
Organisms that come from different ancestors are exposed to similar environmental pressures and become similar to each other |
|
Give an example on convergent evolution |
The wolf and Tasmanian devil are exposed to similar environmental pressures and become similar to each other. |
|
Define comparative embryology |
The comparison of the developmental stages of the embryos of different species |
|
Describe how comparative embryology supports the theory of evolution |
Embryos of different vertebrate groups are similar in their early stages of development. This suggests a common ancestor of vertebrates. |
|
What is paleontology |
The fossil record shows a change from simple organisms in the older rocks to complex organisms in the younger rocks |
|
What are transitional forms |
Transitional forms have the characteristics of different organisms showing the transition from one group to another |
|
How does palaeontology (fossil records) show support for the theory of evolution? |
Fossils of human skulls have been found showing the various stages of transition between primates and humans. This provides support as we see gradual changes in a species over time. |
|
How do transitional forms show support for the theorey of evolutuion? |
Archeopteryx is similar to an extinct group of dinosaurs in many ways except it had feathers and a wish bone like a bird. This transitional form suggests a common ancestor for birds and reptiles. |
|
Define comparative anatomy |
Comparative anatomy is the study of similarities and differences in the structure of living organisms. |
|
Describe the evidence for comparative anatomy |
Similarities that exist amongst groups of organisms suggest that these groups shared a common ancestor and have since evolved to become slightly different due to them specialising for their particular environment |
|
Define biogeography |
The study of geographical distribution of organisms, both living and extinct |
|
How does bio geography show evidence for evolution? |
Organisms showing similarities have been found to exist on continents now separated by water, suggesting common ancestor. |
|
Give an example of biogeography |
Ratitates are flightless birds whom are believed to have all evolved from a common ancestor on Gondwana. |
|
Define biochemical evidence?
|
Comparisons of sequences of chemicals such as: amino acids in proteins OR sequences of base pairs in DNA |
|
How does biochemical evidence support the theory of evolution? |
All organisms have the same basic chemistry: |
|
Explain the significance of small bones with many joints |
Allows flexible and ease of movements; acts as a good shock absorber |
|
Explain the significance of Solid bones that are fused |
Efficient support of body weight; confers strength |
|
Explain the significance of Large bones/large extensions on bones |
Provides sites for large muscle attachment |
|
Explain the significance of light bones (containing spaces) |
Keep light frame (Flight and speed) |
|
Explain the significance of long bones |
Gives good leverage, increase the stride of an animal |
|
Explain the significnace of increased carpal and tarsal bones and lifting of hind end of heel off the ground |
Animal walks up on digits - this increases stride and therefore speed. |
|
Explain the significance of reduced number of digits (e.g. hooves etc.) |
Reduced friction with the ground, increasing speed |
|
Explain the significance of shortened proximal parts of limbs and held closer to body |
Allows attachment and efficient functioning of powerful muscles |
|
Define Gradualism |
Gradualism is the theory of evolution proposed by Darwin-Wallace that assumes living things arose from a common ancestor and that change occurs over a slow, but continuous process. |
|
Define punctuated equilibrium |
Punctuated equilibrium was proposed by Stephan Gould in the 1970's whom proposed that evolution occurs in short bursts of rapid change, folllowed by long period of stability within populations |
|
Which theory of evolution is Darwin-Wallace propose? |
Gradualism |
|
Which theory of evolution did Stephen Gould propose? |
Punctuated equilibrium |
|
Give an example of gradualism |
Very gradually, over many, many, generation, stripes over the tigers' whole body formed and appeared in the whole population |
|
Give an example of punctuated equilibrium |
A long time ago, there were a lot of tigers-like-animals, but without stripes. One time, a genetic mutation occurred in a few of the animals, causing a huge change: they were born with stripes. |