evolution_objectives_unit_4.docx | |
File Size: | 14 kb |
File Type: | docx |
Objective
1 – p. 644
•Evolution – the relative change in the characteristics of populations
that occurs over successive generations.
•population - group of individuals of the same
species living in the same geographical area.
–Ex. All the moose on the Avalon Peninsula
•Adaptation – a particular structure, physiology, or behaviour that helps an organism
survive and reproduce in a particular environment.
Ex. Camouflage helps a rabbit blend with it’s environment.
–If the adaptation helps the organism survive, it can go on to reproduce, and pass
this adaptation to it’s offspring.
–If the environment changes, the adaptation may no longer be an advantage, or other
adaptations that aren’t advantageous NOW may be LATER.
https://www.youtube.com/watch?v=fRX2JtKFUzk – 2:20
•Variation – the forms of a trait; or significant deviations from the normal biological
form, function, or structure.
Objective 2 - The peppered moth (p. 644-46)
•Occurs in England during the Industrial revolution.
•Peppered moth: two variations. (greyish-white and black)
•Black – rare (less than 2%) in 1848
•By 1898, 95% of peppered moths around Manchester were black
•Why?
•Moths rest on trunks of trees. Trunks in 1848 were light in color (birch), so grey-white moths were better camouflaged than black ones
•In the late 1800’s – industrial revolution
•Soot from factories killed lichen on trees and landed on tree trunks.
•Grey-white moths now stood out against ‘dark trees’ – easier prey. Black moths blended better, so went on to have offspring and pass on their ‘dark’ trait
•This happened over several generations (50 years)
•In the 1950’s clean-air laws were put in place
•Less pollution-therefore lichen began to grow on trees again
•Numbers of white moths surviving increased (camouflage once again), while black moths started to drop (less camouflaged).
•By 1985, ratio of black to white moths was 50:50.
•While no new species formed, this is an example of evolution, as there was a change in the gene pool over several generations.
https://www.youtube.com/watch?v=Uf-mOCN7rUU – stop at 3:02
Objective 3 - Artifical and Natural Selection (p. 647)
•Natural selection – process whereby the characteristics of a population of organisms change because individuals with certain heritable traits survive specific local environmental conditions and live to pass these traits on to their offspring. (peppered moth). The environment ‘selects’ who is best suited.
•Survival of the‘fittest’ – which organisms fit in best with the environment.
•Artificial selection – human selection of particular traits by breeding (faster horses, disease-resistant plants, cows producing more milk, dog breeding). Can result in undesirable traits too – lots of pure-bred dogs have problems – hip issues in German Sheppard's. Humans select the animals with the desired traits.
https://www.youtube.com/watch?v=EhkYc7fHcR0 – 3:02
Objective 4 - Contributiors to Evolution & Objective 5 (Darwin) (see attached files) - handout from class
•Evolution – the relative change in the characteristics of populations
that occurs over successive generations.
•population - group of individuals of the same
species living in the same geographical area.
–Ex. All the moose on the Avalon Peninsula
•Adaptation – a particular structure, physiology, or behaviour that helps an organism
survive and reproduce in a particular environment.
Ex. Camouflage helps a rabbit blend with it’s environment.
–If the adaptation helps the organism survive, it can go on to reproduce, and pass
this adaptation to it’s offspring.
–If the environment changes, the adaptation may no longer be an advantage, or other
adaptations that aren’t advantageous NOW may be LATER.
https://www.youtube.com/watch?v=fRX2JtKFUzk – 2:20
•Variation – the forms of a trait; or significant deviations from the normal biological
form, function, or structure.
Objective 2 - The peppered moth (p. 644-46)
•Occurs in England during the Industrial revolution.
•Peppered moth: two variations. (greyish-white and black)
•Black – rare (less than 2%) in 1848
•By 1898, 95% of peppered moths around Manchester were black
•Why?
•Moths rest on trunks of trees. Trunks in 1848 were light in color (birch), so grey-white moths were better camouflaged than black ones
•In the late 1800’s – industrial revolution
•Soot from factories killed lichen on trees and landed on tree trunks.
•Grey-white moths now stood out against ‘dark trees’ – easier prey. Black moths blended better, so went on to have offspring and pass on their ‘dark’ trait
•This happened over several generations (50 years)
•In the 1950’s clean-air laws were put in place
•Less pollution-therefore lichen began to grow on trees again
•Numbers of white moths surviving increased (camouflage once again), while black moths started to drop (less camouflaged).
•By 1985, ratio of black to white moths was 50:50.
•While no new species formed, this is an example of evolution, as there was a change in the gene pool over several generations.
https://www.youtube.com/watch?v=Uf-mOCN7rUU – stop at 3:02
Objective 3 - Artifical and Natural Selection (p. 647)
•Natural selection – process whereby the characteristics of a population of organisms change because individuals with certain heritable traits survive specific local environmental conditions and live to pass these traits on to their offspring. (peppered moth). The environment ‘selects’ who is best suited.
•Survival of the‘fittest’ – which organisms fit in best with the environment.
•Artificial selection – human selection of particular traits by breeding (faster horses, disease-resistant plants, cows producing more milk, dog breeding). Can result in undesirable traits too – lots of pure-bred dogs have problems – hip issues in German Sheppard's. Humans select the animals with the desired traits.
https://www.youtube.com/watch?v=EhkYc7fHcR0 – 3:02
Objective 4 - Contributiors to Evolution & Objective 5 (Darwin) (see attached files) - handout from class
evolution_objective_on_lyell_mathus_wallace_lamarack_cuvier.docx | |
File Size: | 14 kb |
File Type: | docx |
darwin.docx | |
File Size: | 13 kb |
File Type: | docx |
Objective 6
•Darwin was unable to account for the mechanism of inheritance of traits because it was before Mendel’s time (1853) of study of pea plants.
They didn’t know how traits were inherited.
•Darwin was unable to account for the mechanism of inheritance of traits because it was before Mendel’s time (1853) of study of pea plants.
They didn’t know how traits were inherited.
Objective 7 - Geological Time Scale. - P. 660-61
Era showing the first presence of organisms.
•Precambrian –prokaryotes/eukaryotes
•Paleozoic – verts/inverts/jawed fish/land plants/reptiles
•Mesozoic–dinosaurs/mammals/flowering plants/birds
•Cenozoic – placental mammals/humans
Era showing the first presence of organisms.
•Precambrian –prokaryotes/eukaryotes
•Paleozoic – verts/inverts/jawed fish/land plants/reptiles
•Mesozoic–dinosaurs/mammals/flowering plants/birds
•Cenozoic – placental mammals/humans
Objective 8-9 (p. 113 & 662)
•Layer A is youngest (nearest to surface)
•Layer E is oldest
•Fossils in Layer B are older than a fossil in layer A, but younger than fossils in
layers C, D, & E
•Relative dating
– paleontological dating method that provides a rough estimate of the age of
fossils by their position in rock layers.
•Rocks closest to the earth’s surface are considered to be younger than rocks found deeper
•Only provides a rough estimate by using comparisons
•Fossils found in lower layers of sedimentary rock are older than those found in upper layers
•Relative dating tells that one fossil is older than another but does not give the actual age
Everyday example using relative comparasions
•Ex. Zac C. is taller than Ms. Who is taller than Amber L. (whether Ms. is tall or not is relative to whom she is compared. If compared to Zac,
Ms. Isn’t tall. Compared to Amber, she is ;)
•Absolute dating – dating method that accurately determines the age of a fossil by employing fadioactive dating techniques.
•Half-life – the time it takes for half of the radioactive isotopes (the radioactive parent) in a sample to change to another isotope of the same or a different element (the radioactive daughter); used in absolute dating of fossils.
•Basically, the time it takes for one-half of the radioactive material to break down, or decay.
•The half-life of carbon-14 is 5730 years. After 5730 years, half the carbon-14 in a fossil will have changed to nitrogen-14. After 2
X 5730 years (11460 years), one-quarter of the original carbon-14 will remain.
So, what are isotopes?
•Atoms of the same element have the same number of protons (ex. Carbon has 6)
•If they have different numbers of neutrons, they are called isotopes.
•Some isotopes occur naturally (C12, C13, C14).
•C12 – 6 neutrons; C13 – 7; C14 - 8
•If isotopes are unstable, they decay (radioactive) (C14)
•Most decay at known rates
•C14 breaks down into N14
Formula for radioactive decay:
•Nf = final amount
•No = original amount
•t = time
•h = half-life
Formula: Nf = No (1/2)t/h
P.s. 't/h' is the exponent (formatting won't allow me to move it up)
Keep in mind, using this formula you will need to use logarithms if you have an unknown in the exponent (i.e., if you don't know what 't' or 'h' is.
To solve this mathematically, follow this simple rule: if you find the ‘log’ of both sides, the exponent comes down in front of
the number it is above. (See class notes)
•Layer A is youngest (nearest to surface)
•Layer E is oldest
•Fossils in Layer B are older than a fossil in layer A, but younger than fossils in
layers C, D, & E
•Relative dating
– paleontological dating method that provides a rough estimate of the age of
fossils by their position in rock layers.
•Rocks closest to the earth’s surface are considered to be younger than rocks found deeper
•Only provides a rough estimate by using comparisons
•Fossils found in lower layers of sedimentary rock are older than those found in upper layers
•Relative dating tells that one fossil is older than another but does not give the actual age
Everyday example using relative comparasions
•Ex. Zac C. is taller than Ms. Who is taller than Amber L. (whether Ms. is tall or not is relative to whom she is compared. If compared to Zac,
Ms. Isn’t tall. Compared to Amber, she is ;)
•Absolute dating – dating method that accurately determines the age of a fossil by employing fadioactive dating techniques.
•Half-life – the time it takes for half of the radioactive isotopes (the radioactive parent) in a sample to change to another isotope of the same or a different element (the radioactive daughter); used in absolute dating of fossils.
•Basically, the time it takes for one-half of the radioactive material to break down, or decay.
•The half-life of carbon-14 is 5730 years. After 5730 years, half the carbon-14 in a fossil will have changed to nitrogen-14. After 2
X 5730 years (11460 years), one-quarter of the original carbon-14 will remain.
So, what are isotopes?
•Atoms of the same element have the same number of protons (ex. Carbon has 6)
•If they have different numbers of neutrons, they are called isotopes.
•Some isotopes occur naturally (C12, C13, C14).
•C12 – 6 neutrons; C13 – 7; C14 - 8
•If isotopes are unstable, they decay (radioactive) (C14)
•Most decay at known rates
•C14 breaks down into N14
Formula for radioactive decay:
•Nf = final amount
•No = original amount
•t = time
•h = half-life
Formula: Nf = No (1/2)t/h
P.s. 't/h' is the exponent (formatting won't allow me to move it up)
Keep in mind, using this formula you will need to use logarithms if you have an unknown in the exponent (i.e., if you don't know what 't' or 'h' is.
To solve this mathematically, follow this simple rule: if you find the ‘log’ of both sides, the exponent comes down in front of
the number it is above. (See class notes)
Instead of using the above formula to calculate half-life problems - using this table as a template will allow you to figure out any half-life problems that deal with percentages or fractions.
Objective 10 - solving half-life problems - worksheet handed out in class.
Objective 10 - solving half-life problems - worksheet handed out in class.