Lecture 3 - Evolution Theory 2

Question 1

4 Levels of Analysis

Answer 1

1. Proximate
   
   1. Mechanism: what are the structural components
   2. Ontogeny: how does it develop
2. Ultimate
   
   1. When did it evolve?
   2. What selection pressures shaped it?

• Developed by Niko Tingergen

Question 2

Group Selection

Answer 2

• Group/Kin selection are mathematically equivalent
  
  • Changes in allele requency can be counted in many different ways
• Group selection models have no examples in nature yet, but it’s mathematically sound

Question 3

Group vs. Individual Level Adaptations

Answer 3

Group

• An adaptation that evolved because it maximizes group fitness
  
  • Genes within the group must share a common fate
  • Selection maximizes group fitness if they are genetically related or no genetic conflicts
  • E.x. None

Individual

• An adaptation that evolved because it maximizes individuals fitness
  
  • Genes within individual must share a common fate (equal chance of representation in next generation)
  • E.x. Gametes have equal chance of being housed. Independent assormtnet of chromosomes, recombination in meiosis, organs/biochemical processes

Question 4

Individual level adapations informing biology

Answer 4

• Every organ has a relation to energy regulation (which are all evolved adaptations) – shows the concept is useful at the chemical and organ level
• Vascular system is also involved this (transportation of nutrients to the body). Has a fractal network. Fractal networks solve the major problem of efficient nutrient transmission. So efficient and under selection for so long that plants use this network too.
• Pushes into economics

Question 5

Adaptionist vs non adapt theories

(Constraint)

Answer 5

• A trait that is not able to reach an optimal design
  
  • All traits can’t be adaptations.
• These theories are not mutual exclusive alternatives, and can only be if asking what is the best explanation for a triat
  *

Question 6

Signs of Adaptation

(What do they have to prove)

Answer 6

• Evidence of ancestral selection pressures
• NS only known force that can generate non-random organization/coordination
• Adaptationist explanations have to show that this trait is not better explained by some other thing

1. Traits have effects
2. Effects represent how traits interact with the environment
3. Sometimes effects promote propagation of genes
4. When propagative features of the environment persist over long periods of time, complex adaptations evolve

Question 7

Reverse Engineering Process

Answer 7

• Deconstruct the trait’s structure
• Figure out how the components interact with each other
  
  • Does the structure and operation suggest non-randomness
  • Is the non-randomness promoting a unique effect?

Question 8

Burden of Proof

Answer 8

• Have I shown that all alternative hypotheses are implausible

Question 9

Identifying Adaptation

Answer 9

• Evolved function is identified by deconstructing the trait’s structure and figuring out how the components work together
  
  • Determine it didn’t evolve by chance
  • Determine whether non-random structure promotes single useful effect
• When we study the structure and operation of adaptations of an organ or area, we can learn more about the malfunction and cause of the disorder
  
  • Mapping a structure provides a conceptual blueprint
  • We define disorder from a properly defined adaptation

Question 10

A trait can be best explained by (Exaptation, Constraint, Byproduct) if:

Answer 10

• Exaptation: Fails to show evidence of non-random organization or coordination for the beneficial effect
• Constraint: It deviates from a clearly more optimal design
• By-product: It failts to show signs of non-random structure or operation, and lacks any beneficial effect

Question 11

Adaptionist Research Strategy

Answer 11

• Strategy: Adaptionist - When one takes an adaptoinist approach you are determining whether a treat is best explained by the concept of an adaptation or some alternative adaptation
  
  • Doesn’t mean you are committed to the idea it’s an adaptation

Question 12

Disorder as Dysfunction Concept

(3 possible meaning of function)

Answer 12

• Psychiatry acknowledges disorder as involving dysfunction

1. Any beneficial effect of trait/object
   
   1. But a clock can also be a good paperweight, so dysfunction has to mean that anytime your brain does something not useful
2. The purpose in which it was created for
   
   1. Can’t use this when talking about natural traits
3. Explains the structure and operation of the trait
   
   1. Best explanation
   2. NS only known explanation for biological traits with function

Answer 13

• Harmful Dysfunction: Every true instance of disorder involves a malfunction in an evolved adaptation
• Also involves a social judgment of harm
• Malfunction is an evolved adaptation (scientific), social judgement is not.
  
  • We don’t consider the inability to produce a fingerprint as a malfunction
• Jerome Wakefield is a proponent of this