1
Q
What is evolution?
A
Change in (biological) entities over time over generations.
- Could be a change of a DNA sequence or the makeup of populations
2
Q
How is evolution viewed?
A
Evolution is a unifying concept in fields of biology.
3
Q
Biological evolution distinguishes?
A
The main properties that distinguish living and non-living entities is the ability to participate/experience biological evolution.
4
Q
Importance of evolution?
A
Evolution is important in of itself and also important to many other aspects of biology (and life sciences in general)
- Important in medicine, genomics, and ecology
5
Q
Evolutionary science?
A
Evolutionary sciences are necessary to understand how the earth works.
6
Q
Example of microevolution by natural selection?
A
The different variants and sub-variants of COVID-19 can be explained by microevolution alongside how they appeared at different times.
- New variants of the virus were created to replace old variants. The new ones were made to be easier to transmit rather than the old ones.
7
Q
Example of macroevolution?
A
The crossing of the respiratory and digestive tracts is the product of our evolutionary history.
- This is the way it works because it is the end product of years and years of evolutionary history.
8
Q
How does Darwinian evolution hold up now?
A
Darwin’s main ideas have been proven to be fundamentally correct!
9
Q
What ideas are fundamental to the foundation of evolution?
A
Darwin had two main ideas:
- Tree of life
- Evolution by natural selection
These ideas are the fundamental foundation of evolution.
10
Q
When was “The Origin of Species” published?
A
It was published in 1859, by Charles Darwin.
11
Q
Content of “The Origin of Species”?
A
- It goes into great detail about his ideas and concepts of evolution, also containing a lot of supporting information.
- Ideas about evolution alongside the notion that it has occurred, leading to the pattern of having diversity of life on Earth through certain mechanisms.
12
Q
Importance of “The Origins of Species”?
A
Very important to the history of biology and history of scientific thought processes.
13
Q
Effect of “The Origin of Species”?
A
After it was published, evolution went from being a fringe theory to being widely accepted.
14
Q
Biology before evolution was agreed upon?
A
There was the idea of there being fixed species on earth.
15
Q
Idea of fixed species?
A
The idea of fixed species refers to the idea that species are unchanged and perpetual.
- Organisms were put on earth by a Greater Being and have been the exact same since their creation.
- Scala naturae idea
16
Q
Concept of Scala naturae?
A
The concept of Scala naturae was there being a ladder of increasing organism complexity. Very popular idea.
- species would all have a place on the scale based on increasing complexity (perceived)
- the species place on the ladder is completely up to the person who makes the ladder.
17
Q
Who was Carolus Linnaeus?
A
He is known as the father of taxonomy (biological classification).
18
Q
Linnaeus promoted the ideas of?
A
He promoted the ideas of Hierarchical, Nested Classification and formal ranks.
19
Q
Longevity of Linnaeus?
A
The science of classifying species idea has longevity and organizing information about them.
20
Q
Linnaeus’ beliefs?
A
- Linnaeus did not believe in evolution
- He believed that there are fixed species
- He thought that his system of classification fits the world better than the other systems proposed.
21
Q
Linnaeus’ System: Good or Bad?
A
It is a really good system, because it fits really well with the evolution pattern proposed by Darwin.
22
Q
What is Linnaean classification?
A
It is composed of different taxa - boxes within boxes from more general to very specific.
23
Q
Scala Naturae vs. Linnaean Classification?
A
Scala Naturae could vary by what scientist it was who organized it. Subjective concept.
Linnaean Classification follows many rules and is very objective.
24
Q
Linnaean Classification =
A
Hierarchical Nested Classification
25
Whose approach do we use?
We still use the Linnaean classification approach today.
- General concept of how to organize species into groups where we can make general claims about them is what we use today.
26
When did palaeontology begin gaining popularity?
The study of palaeontology began gaining popularity around the time of Linnaeus' death (later 18th century)
27
What is palaeontology?
The study of fossils, a preserved record of things that used to be alive.
- Biological history preserved in geological site.
28
What could be observed by palaeontology?
Rocks of different age in the same location contain different species. This is because rocks layer on top of older layers, allowing us to go back in time and observe what the world looked like back then.
- Fossils from different times are held within different layers of the earth's rocks, younger is at the top and older rocks are at the bottom.
29
Palaeontology and Extinction?
Many species preserved as fossils are no longer seen on Earth: Extinction.
- The reality of extinction became very clear from observing the fossil record.
30
What did Lamarck do?
He observed the progressions of similar species in the fossil record.
- Very similar traits/characteristics in different species. Why?
31
What was his idea?
Species A is not replaced by species B, but it is changed/modified into species B through evolutionary change.
32
What was Lamarck's proposal?
New species arise by the modification of existing species. This is an evolutionary explanation of what Lamarck saw.
33
Were Lamarck's ideas correct?
No, they were not correct but they provide necessary context for proving Darwin's points as more correct.
34
What patterns did Lamarck observe?
- The living world is made up of many separate lineages with independent origins.
- Each lineage progresses (‘strives’)
towards greater complexity or perfection.
35
Lamarck's other ideas?
The living evolve and evolved from the non-living many times in Earth's history at many different times.
- Each lineage has a tendency to change into more complex forms
- In the example, species (a-b-c-d) had more time to evolve and is therefore more complex.
36
What was Lamarck's Process or Mechanism?
Use-and-disuse of parts, with inheritance of acquired characters that add up over time. This is called "Lamarckism"
37
How correct is Lamarckism?
The idea of the "Use and disuse of parts" is true for many parts of biology, but not for evolution.
38
Example of Lamarckism?
- Developing stronger muscles with more use would make your offspring more stronger at birth.
39
Lamarckism?
The INDIVIDUALS evolve rather than the population!
40
Use and disuse of parts?
During your lifetime, there more you use something, the more likely you'll end up with a more developed version of it.
- A character is acquired during one's lifetime and then pass on the tendencies for that characteristic to your child. INCORRECT!
41
What does Lamarck's idea explain?
- Explains variation in ‘complexity’
among species
- Mechanism not well supported
(in hindsight) knowing that acquired characters are not inherited.
- Poor fit to biological classification and doesn't fit with Linnaean ideology.
42
Background information on Darwin?
Medical school drop-out
- family was very wealthy
Interested in natural world (B.A.1831)
- went to Cambridge and looked at ricks and living organisms
1831-1836: Beagle* expedition
- Whilst travelling he went on many natural history explorations in the Southern hemisphere
1859: Publishes ‘The Origin of Species’ introducing his theory of evolution
- His explorations and observations informed his work on evolution and gave him a place to work from.
43
What were Darwin's two main ideas?
He had an idea about the pattern and process of evolution.
44
What was Darwin's pattern idea?
- Living things are all united in one
branching tree of relationships, with there being exactly one origin of life.
- New lineages are constantly being created by existing lineages splitting in two.
45
Branching Tree of Life idea?
A series of events where one lineage (group of species) evolves into another and splits into two.
- Then they continue to evolve with these events happening over and over again.
46
What is a common ancestor on the tree of life?
All species, alive or not, are related in some way, the degree of how much is captured by the tree.
47
What is the most recent common ancestor?
The most recent common ancestor is the species that would have branched into the two species (A and B have the same most recent common ancestor)
48
Descent with modification: Unity?
Species A and B are similar because
of their shared history before their
most recent common ancestor.
- They are united
49
Descent with modification: Diversity?
Species A and B also differ from one another in many ways:
this is because of independent changes in their lineages after divergence from their most recent common ancestor
- they are diverse
50
Diversity?
A and B share descent but ALSO experience independent evolution, each becoming more diverse from one another in that way.
51
Tree of life & Linnaean Classification?
Tree of life: Darwin's idea
Linnaean: Works with TOL
- They work together very well
- A and B's most common ancestor therefore means that A and B are the most similar organisms
52
What was Darwin's idea of a process?
- Evolution occurs primarily because of the action of Natural Selection which causes evolutionary change in populations.
Key point: Individuals of a species
belong to populations
53
What is a population?
A grouping of organisms who are going to evolve by interacting or interbreeding.
54
What evolves by Darwinian logic?
The unit (population) will evolve, NOT the individual.
55
Ingredients of Natural Selection?
- Heritable Variation
- Excess Production
- Differential Success (how many offspring they can expect to have on average)
56
Heritable Variation?
- Individuals in a population are born
differing in many traits/features. All of them are different from one another (have different genetic makeups).
- Many traits can be passed on from
parents to offspring (heritable traits)
57
Excess Production?
In any population, more offspring are produced than ‘needed’ to maintain it. (usually many more)
58
Consequence of Excess Production?
When resources are limited, many of the offspring fail to survive. (or, at least, do not reproduce)
- Causes competition within species.
59
Struggle for existence?
Competition begins within a population and there are only enough resources for some to survive and reproduce.
- it is not fair and some have a greater chance of success.
60
Differential Success?
Because of their differing traits, some
individuals are more likely than others to survive & reproduce
They will then produce more viable offspring on average
61
Fitness?
The higher the fitness, the more offspring that will be made.
62
Favourable traits?
Will increase in frequency
63
Heritable traits tend to?
Heritable traits that have helped individuals have more viable offspring on average will tend to be
passed on to those more numerous offspring.
With time, these traits will tend to become more frequent in the population (& unfavourable traits become less frequent as they are passed onto a smaller portion of the population).
This is evolution as the population has evolved.
64
Evolution occurs?
Over many, many generations. With many traits over many generations you will see large scale evolution as there is enough time for change to keep occurring.
65
What does natural selection act on?
Natural selection acts on existing variation rather than generating that variation.
66
What does variation arise from?
We now know that variation arises ultimately from mutation (changes) in the genome (genetic mutations).
67
What did Darwin know about variability?
Darwin didn’t know the mechanism behind variability and heritability, but he observed the results...
- He had no concept of what genes are or transcription or anything like that.
68
Artificial selection?
Artificial selection on heritable variation that is present or arises in existing species shows the plausibility of evolution by natural selection on the same variation present in the population
69
Example of Artificial selection?
Livestock breeding or hobby breeding: hoping for a certain combination or a more fascinating, eye-catching variant.
70
What does Artificial selection prove?
It proves that there is heritable variation in populations for natural selection to act on.
- If artificial can occur so can natural!
71
How fast is Artificial selection?
Much faster than natural selection.
72
Natural selection results in?
Natural selection over time will result in adaptive evolution (adaptation).
- Natural selection will cause evolutionary change but it'll cause adaptive evolution over time.
73
Adaptive evolution (adaptation)?
The suitability of organisms to their environment. When organisms are well-suited to their environment they will have longer life spans.
74
Example of adaptive evolution?
Fox species with different adaptations to different environments.
Example: different colouring, coat thickness, ear size
75
Darwinian evolution progress?
There is no universal direction of progress in Darwinian evolution.
- There is nothin about Darwinian evolution that claims that every species/organism will become more complex over time, which contrasts Lamarck's ideas.
76
Example of progress in Darwinian evolution?
Giraffes are well adapted to browsing and very complex, yet they are slow to reproduce.
Bacteria are well adapted to rapid reproduction, but are extremely simple (in comparison to giraffes).
Both of them are different complexities but that is okay according to darwinian evolution.
77
Direction of darwinian evolution?
could be either:
complex - simple
simple - complex
BIOL1010/1011
flashcards
Decks in class (37)
# Cards
-
Genetics: Lecture 179
-
Genetics: Lecture 243
-
Genetics: Lecture 336
-
Genetics: Lecture 483
-
Genetics: Lecture 552
-
Genetics: Lecture 674
-
Genetics: Lecture 738
-
Evolution: Lecture 177
-
Evolution: Lecture 253
-
Evolution: Lecture 353
-
Evolution: Lecture 433
-
Evolution: Lecture 557
-
Evolution: Lecture 639
-
Evolution: Lecture 741
-
Evolution: Lecture 825
-
Plants: Lecture 160
-
Plants: Lecture 269
-
Plants: Lecture 365
-
Plants: Lecture 467
-
Plants: Lecture 563
-
Plants: Lecture 667
-
Plants: Lecture 742
-
Ecology: Lecture 192
-
Ecology: Lecture 290
-
Ecology: Lecture 392
-
Ecology: Lecture 480
-
Ecology: Lecture 561
-
Ecology: Lecture 670
-
Ecology: Lecture 760
-
Animal: Lecture 162
-
Animal: Lecture 251
-
Animal: Lecture 357
-
Animal: Lecture 486
-
Animal: Lecture 565
-
Animal: Lecture 664
-
Animal: Lecture 757
-
Animal: Lecture 839
