Pre-Midterm 1 Material

Question 1

What is a cheetah?

Applies to all living species including humans

Answer 1

A cheetah is a mammal characterized by few evolutionary traits that distinguishes it from other feline species. The species is the result of 3500 myr of evolution where more than 99% of its characteristics have evolved in species that are now extinct and less than 1% of its features are unique. Thus the cheetah is mainly the result of the history of its ancestors than its own history.

Question 2

What are the types of scientific reasoning, and what are they?

Answer 2

1. Inductive Reasoning is linked to a descriptive-based approach which is to make a generalization based on numerous specific observations. Making a broader reason, particular to general. Ie. you make an assumption (generalization) from what you saw(observation)
2. Deductive Reasoning is linked to a hypothesis-based approach which involves stating a hypothesis to draw conclusions after experimenting or observing hypothesis. Making a specific reason, general to particular.

Question 3

What is an if-then statement?

Answer 3

A prediction.

Question 4

What is an assumption?

Answer 4

A hypothesis

Question 5

How is the scientific process conducted?

Answer 5

1. Observation
2. Hypothesis
3. Predictions
4. Tests
   5a. If hypothesis is refuted then a new a hypothesis must be made
   5b. If the hypothesis is not refuted additional tests must be made to ensure that the hypothesis is not refuted

Question 6

What is the scientific process?

Answer 6

The contract between science and knowledge.

Question 7

What are the four clauses of the scientific process

Answer 7

1. Initial skepticism on facts
2. Realism
3. Rationality: Logic and Parsimony
4. Methodological Materialism

Question 8

What is skepticism?

Answer 8

Asking honest questions on facts and hypothesis. Always retesting what has been found.

Question 9

What is realism?

Answer 9

The world is older and exists independently from my perception of it where the realm of ideas doesn’t have the priority over the real world.

Question 10

What is rationality?

Answer 10

Logic: demonstrations from a scientist must be the result of
coherent steps.
Parsimony: methodological principle which states that acceptable theories are hypothetically the most economical in assumptions.

Question 11

What is methodological materialism?

Answer 11

All that is experimentally accessible in the real world is material or has a material origin.

Question 12

How does Darwin comprehend the resemblance of species & what does it lead him towards?

Answer 12

Darwin comprehended resemblance of species through phylogenetic trees that species show resemblance to each other because they share a common ancestor not a common environment. Darwin’s phylogenetic terres confirmed what he knew through observation but not yet the mechanism of evolution. Darwin rejects Lamarck’s evolutionary mechanism of environmental determinism. Darwin rejects the fixity (no change) of species and accepts the concept of descent with modifications (evolution). Darwin also begins to have a very materialistic view of life that is in contradiction to the religious dogma of the time. This leads him to begin the search for an evolutionary mechanism.

Question 13

What did Darwin observe in the finches of the Galápagos Islands?

Answer 13

The finches show morphological similarities because they share a COMMON ANCESTOR which clarifies their link to South America.

Question 14

What are fossils helpful towards?

Answer 14

Fossils fill in the important gap in morphology. Fossils explain morphological variability/differences and the evolution of morphology. Since most of the evolutionary branches finish in extinction where 99% of species are extinct and 1% of species are living which is why fossils help us corroborate.
(All share common ancestor: Rock hyrax, African elephant, dugong)

Question 15

What book did Darwin read in 1838?

Answer 15

Darwin read “An Essay on The Principle of Population” written by Thomas R. Malthus. Thomas R. Malthus wrote that every human population has a tendency to increase geometrically (exponentially) whereas the available resources to feed these populations increase arithmetically (linear). Where the human population increases faster than its capacity to feed itself leading to a crisis point (of chaos, famine sickness, war). During that period the individual population will want to secure itself where there will be a winner/loser situation where the losers will have no food, unable to reproduce, and die. Eventually the population will collapse to a substantial reduction in size. This reading became one of the main sources to inspire him to formulate his famous theory on natural selection.

Question 16

What does Thomas R. Malthus’ principle of population graph look like?

Answer 16

The human population is increasing concave up and intersects with the linear growing resources where the human population goes through a turning point increasing concave down then decreases concave down to then hit the linear growing resources where the situation returns back to normal.

Question 17

What are Darwin’s observations?

Answer 17

1. Darwin’s first observation: All species can produce more offspring than their environment can sustain and many of these offspring fail to survive and reproduce. Ex. Mushroom puffball reproduces a spore cloud which contains billions of spores, maple trees reproduce samaras, and the mola mola- ocean sunfish will produce over 300 million eggs
2. Darwin’s second observation: Members of a population often vary in their inherited traits. (Dots from the Asian ladybird beetle and the shell colour of amphidromus adamsii are genetic traits)

Question 18

What is natural selection? What are its inferences?

Answer 18

Natural selection enables the emergence of adaptations. They infer that:

1. Individuals whose inherited traits gives them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals
2. In generational shifts there is an unequal capacity of survive and reproduce called a differential reproductive success which results in an accumulation of favourable traits in a population essentially greater proportion and frequency will increased of a certain phenotype/genotype limiting genetic variability

Question 19

What are important notions linked with natural selection?

Answer 19

1.Individuals do not evolve only populations evolve
(Individuals are only carriers of gene) (Lamarckism: individual ≠Darwin: population)
2. Only hereditary traits are subjects to natural selection
3. Genetic variability is needed for evolution to occur
4. Natural selection corresponds to differential reproductive success within a population from generation to generation (like a change in frequency of genotype)
5. With time, natural selection enables individuals to become better adapted to their environment
6. Environmental factors vary in time and space thus the selective forces are variable (summer vs winter, white-tail deers in Ontario+Quebec vs Costa Rica)
7. Traits in populations will change and can modify the species (change in morphology ie use of utensils means less pressure on our jaws thus they are becoming smaller)

Question 20

How did Darwin justify the mechanism of natural selection as valid?

(What is differential reproductive success)

Answer 20

1. Natural selection respects the principle of uniformity of Lyell and Hutton
2. The results of natural selection are visible in nature
3. Natural selection can be verified on current populations through artificial selection
4. It is a materialistic concept (no need for divine intervention) because of two things, that:
   a. Natural selection is not a random process and it enables individuals that are better adapted to their environment to become more abundant in the population than those who are not which is the idea of differential reproductive success
   b. Natural selection is not a quest for perfection, evolution is not a directed process. It does not lead to the appearance of “perfect” traits. Organisms only adapt to their environment, some become more abundant in an environment or some traits are selected due to a predation factor ONLY TO ADAPT & SURVIVE

Question 21

What is the difference between artificial selection and natural selection?

Answer 21

Artificial selection is finalized because the goal or objective, is fixed well in advance, and it precedes the cause. The end result can be obtained in a few generations. Natural selection is not finalized as it can take a long time for changes to occur, functions through geological time scale.

Question 22

Provide an example for artificial selection.

Answer 22

Our food is artificially selected. A wild mustard plant that is artificially selected for its leaves is kale, for its apical buds is cabbage, for its auxiliary buds is Brussels sprouts. A mop dog is achieved by artificially selecting dogs with longer coats to breed.

Question 23

Provide three examples of natural selection.

Answer 23

1. Humans: adaptation to altitude in:
   a. Andes: mutation for increase in hemoglobin concentration
   b. Tibet Plateau: mutation (involving multiple genes) deeper breath, larger pulmonary capacity and increased blood flow
   : genetically favoured in Plateau, as the abundance of individuals withstanding (genetic traits allowing for survival and reproduction in) high altitudes increased through time as they had differential mortality and reproductive rates
2. Medium Ground Finches: Climate (drought) in Daphne Major Galápagos Islands substantially decreased population because selection favoured individuals that had bigger and stronger beaks to break Available seeds during drought thus lowered abundance from small-beaked birds as limited reproduction and many died.
3. Moths: selected in way of feeding. Dark morphs were more frequent on soot-infested trees (urban) while grey morphs were more frequent in countryside because of lighter coloured trees and predators were attracted to eating more vibrant food as it also easier to see (black/grey hereditary trait helped them camouflage depending on tree colour)

Question 24

What do all cases of natural selection provide?

Answer 24

Natural selection provides the hereditary traits that give a reproductive advantage to individuals in a population will be favoured. Thus from generation to generation there will be a higher percentage of individuals carrying the adaptation. That is natural selection, Darwin’s descent with modification, evolution. These adaptations can sometimes redefine a species and rarely define into a new species.

Question 25

Where can we understand where species come from (and how can we properly categorize them). Give example of whale.

Answer 25

Fossils provide key information to fill in important gaps in morphological differences and variability because 99% of species from earth are extinct and only 1% of species are living today, so most evolutionary branches finish in extinction. Through fossils we can understand that the pakicetus, whale, and hippo share a common ancestor.

Question 26

What is a vestigial structure and provide four examples.

Answer 26

A vestigial structure is an anatomical structure that is present yet has lost almost all of its initial function, and they are proof of evolution as they are remnants of what was once fully functioning in a an ancestor.
Examples:
1. Third Eyelid/ Nictitating membrane: no reason to have has no function, just sits there
2. Appendix: an ancestor had a fully functioning caecum and our small appendix is remnant of that, no longer need large digestive system because of introduction of meats into our diet no pressure to digest cellulose (plants)
3. Goosebumps and hair: no reason to have muscle associated with contracting every hair follicle nor do we have any hair density to help us retain heat
*4. Hiccups: is a very light pinch on phrenic nerves which contracts the epiglottis and diaphragm this is where our nerve followed the evolutionary pattern of fishes because fishes’ movement of their gills is associated with the phrenic nerve.

Question 27

What would be sufficient to refute the whole concept of evolution?

Answer 27

The discovery of a fossil in the wrong place in the geological archives.