Final Review From Lectures 1-8 Flashcards
What is Descent with modification?
Evolution
What are the 3 Types of adaptations that exist to enable species to survive?
- Structural (Physical Features)
- Behavioural (Learned or Inherited Actions)
- Physiological (Internal and Cellular Processes)
What is Biological Fitness?
(3)
the ability of an individual:
1. to survive to reproductive age,
2. find a mate,
3. produce live, fertile offspring
(relative to that ability in other individuals in the population)
What are Homologous Structures?
(Homology)
- homologous structures are body parts that share a common ancestor, but may not necessarily perform the same function
Example:
– Forelimb bones in a human arm, horse leg, seal flipper and bat/bird wing
What is Divergent Evolution?
a process in which a trait held by a common ancestor evolves into different variations over time
What are Analogous Structures?
(Homoplasy)
What are some examples?
body parts that perform the same function, but have a different evolutionary history
(so the similarity in function NOT resulting from common ancestry)
Examples:
– Walking limbs of insects and vertebrates
– Wings of birds and bats look similar in the structure though they evolved independently
– Cranium of vertebrates and exoskeleton head of insects
– Eye of octopus and eyes in humans
– Arctic fox and ptarmigan (a bird) both under seasonal changes of colour from dark to snowy white
EXAMPLES OF NATURAL SELECTION
peppered moths
What is Sexual Selection?
- A form of non-random mating, which occurs when individuals within a population differ in their ability to attract mates
- This type of selection favours individuals with heritable traits that enhance their ability to obtain mates
- A component of natural selection in which mating success traded for survival
What is INTERSEXUAL Selection?
- Intersexual selection: mating success determined by between-sex interactions
- In other words, this type of sexual selection looks at mate choice (i.e., choice exerted by members of the opposite sex)
- More specifically, the common scenario is a female choice of males (so males must show themselves to be genetically attractive to females)
What is INTRASEXUAL Selection?
- Intrasexual selection: mating success determined by within-sex interactions
- individuals competing to obtain mates (same sex)
- For example, male-male combat over females or resources vital to mates (this often results in body size sexual dimorphism, meaning in
this case that males are much larger than females and often have adaptations to fight other males)
What is the Fundamental Asymmetry of Sex?
in most species, females invest more in their offspring than males
What are the 2 Consequences of the Fundamental Asymmetry of Sex?
- Female fitness is limited by the ability to gain resources needed to produce more eggs and healthier offspring, so females produce relatively few offspring during lifetime
- Male fitness is limited by the number of females he can mate with, and he can mate frequently because sperm are so energetically inexpensive
What is Male-Male Competition?
Males that win battles with other males monopolize matings with females in their territory
o Fights are usually won by the larger male
o Dominant males father a large number of offspring
o Males that lose fights father few or no offspring
– Thus, alleles from large successful males will increase in
frequency in the population
– If the ability to win fights and produce offspring is determined
by body size, then alleles for large body size have a significant fitness advantage
What is Sexual Dimorphism?
Sexual dimorphism refers to any trait that differs between males and females of the same species
– Weaponry
– Ornamentation and behaviour in courtship
– Body size
What is Monogamy?
(Pair Bonding)
the pattern of having one mate at a time –
one male and female have an exclusive mating relationship
(more usually called pair bonding)
