Intro to evolution Dr Marta Flashcards
(25 cards)
What is the theory of evolution?
Evolution as we understand it today is a theory, based on SCIENTIFIC EVIDENCE that provides a testable mechanism which can explain the formation of life and the diversification of species.
What is scientific theory?
- Observe and collect facts
- Make a hypothesis to explain facts.
- Using hypothesis make prediction
- Test prediction
- Reject or improve hypothesis and repeat.
If hypothesis stands up it is a theory
How do using a cocktail of drugs challenge a viruses ability to survive?
Now we use a cocktail of drugs targeting several genes in the virus, making it more difficult for the virus to acquire beneficial mutations.
What is the beginning of evolutionary study?
330BC
Aristotle’s scala naturae.
What is the latest milestone in evolutionary study?
1859
The origin of species published.
What is Aristotle’s scala naturae?
Ordered organisms into a linear sequence from least to most complex
It fuelled the views of natural theology – the world could only be created by an intelligent designer leading to the Special Creation view of life:
What did Caroleus LInnaeus produce?
Bi-nomial naming system(Homo sapiens)
KPCOFGS
Kingdom
Phylum
Class
Order
Family
Genus
Species
What did George Cuvier produce from his evolutionary studies?
Cuvier publishes his
extensive studies of
vertebrate fossils.
led the foundations for darwin through age of fossils are reasoning for extinction
What did lamark discover from his studies?
A change in the environment causes changes in the needs of organisms living in that environment, which in turn causes changes in their behavior.
Altered behavior leads to greater or lesser use of a given structure or organ; use would cause the structure to increase in size over several generations, whereas disuse would cause it to shrink or even disappear.
What were the three observations explained by darwin in the origin of species?
1) The unity of life
2) The diversity of life
3) The match between organisms
and their environment
Name a vestigial structure?
Useless body part,
e.g tail bone(coccyx)
Give some evidence of microevolution?
Selective breeding or artifical
Give some evidence of speciation?
From natural populations, populations can DIVERGE to the point that their Individuals can no longer interbreed(types of fish)
Give some evidence of macroevolution?
From transitional forms.
fossils show mix of features
traits typical of ancesters and novel traits seen later in descendants.
e.g dinosaur to crow
Also from continental drift(pangea)
What is homology?
is similarity resulting from common ancestry
What are the genes of molecular homology?
The Homeobox (HOX) genes
What are hox genes?
regulatory genes that control the timing and route of development.
Hox proteins are transcription factors, as they are capable of binding to specific nucleotide sequences on the DNA called enhancers where they either activate or repress genes.
What can result from an error in hox genes?
Expression of a HOX gene in the wrong place at the wrong time can engage the wrong programme and make the wrong limb, or more than the usual number for example.
Describe the evolution of hox genes?
When a Hox gene was duplicated, the functions of the two copies diverged and each evolved a special role in the development of the animal. However some sections of the gene remained the same – they were conserved – these allow us to see how the genes are related.
Describe how natural selection is the mechanism for evolution?
The individuals within a population differ from one another.
The differences are, at least in part, passed from parents to offspring.
Some individuals are more successful at surviving and reproducing than others.
The successful individuals are not merely lucky; instead, they succeed because of the variant traits they have inherited and will pass to their offspring
Describe how natural selection is not forward-looking?
Organisms CANNOT be adapted in advance to future conditions
Selection CANNOT anticipate environmental conditions that will occur during future generations
Describe how natural selection does not lead to perfection?
Better-adapted organisms DOESN’T MEAN they are perfect
NS occurs among existing variants and cannot simultaneously optimise all traits
How is natural selection non-random?
Only the variants leading to better survival and reproduction will persist.
How is natural selection non-progressive?
evolving populations improve only in that their average adaptation to the environment increases
No trend towards more complex or advanced life forms: complex traits are often lost (f.e. snakes and legs)
Therefore, there is no such thing as higher or lower plant or animal.
Basically no animal is higher or lower just more suited to a certain environment.
