Biology - Final

What 7 explanations have been proposed about "The Problem of Altruistic Behavior" of animals? Which is believed to be the most common and important?

• Mistakes

  • Apparent altruism is misplaced selfishness

  • Mexican free-tailed bats

• Exploitation by natural enemies

  • Manipulated by a selfish, co-evolved natural enemy

  • Hosts feeding cuckoo chickens / intraspecific brood parasitism

• Parental manipulation

  • white-fronted bee eaters

• Group selection

  • almost universally rejected

• Long-term selfishness

  • Florida scrub jay helpers

• Reciprocity

  • time delayed mutation

  • rare because it requires advanced cognitive ability

  • Primate groomers, vampire bats

• Kin selection → most common & important

What is Hamilton’s rule?

Helps us see how both genetic & ecological factors affect whether or not altruistic behavior is favored by NS

Altruism will be favored when:

rB > C, where

• B = benefit to the recipient

• C = cost of altruist

• r = coefficient of relatedness

Define population as according to genetics & ecology

• Genetics - an interbreeding group of individuals comprising one gene pool

• Ecology - a group of individuals living in a particular place

What are the 2 "Primary Population Parameters" that decrease a population

• Mortality

• Emigration

What are the the 2 "Primary Population Parameters" that increase a population

Natality & Immigration

What are the basic measures of population ecology

• Range

• Abundance

• Dispersion

• Density (#/area)

  • crude vs. ecological

    • crude measures population size relative to the entire habitat area

    • ecological measures population size relative to the specific, habitable space actually used

  • absolute vs. relative estimate

What is the name of the interspecific interaction type in which:

(a) both species benefit

(b) one species benefits & the other is harmed

(c) both species are harmed

(a) mutualism

(b) predation/parasitism

(c) competition

What are the density-independent factors & density-dependent factors

• Density-Independent: Usually physical (climatic factors)

• Density-Dependent: Usually biological

  • Intra-specific vs. Inter-specific interactions

  • Positive density dependence (allee effect)

    • the more there are, the more are born

  • Negative density dependence

    • the more there are, the less are born (limited amount of food)

Give one of the population growth equations for exponential growth

• N_t = N₀R₀^t

• N_t = N₀e^rt

• dN/dt = rN

Give the Pearl-Verhulst Equation for logistic growth of a population

dN/dt = rN (K-N/K)

What is the difference between Physiological Longevity & Ecological Longevity

• P → potential longevity in absence of negative factors

• E → actual longevity in the natural environment

Draw a graph showing the three different Survivorship Curves

What survivorship curve is typical of mammals?

Type 1

Draw a Natality (Fertility) Curve for mammals

Draw an age pyramid that would be indicative of a population that is increasing in numbers

Give an example of a country that has an age pyramid such as the one in question 9

India

In the context of Interspecific competition, what is an “alpha”

Effect of a member of species 2 on species 1

From the graphical models of Interspecific Competition, what are the 4 possible outcomes

• Species 1 wins

• Species 2 wins

• Unstable Equilibrium - one will win, but could be either

• Stable co-existance

State “Gause’s Competitive Exclusion Principle”

“Complete competitors cannot co-exist”

List 5 patterns that suggest interspecific competition had gone on in the past, & give 1 example

1. Niche differences in sympatric close relatives → English titmice

2. Niche differentiation in guild members → rodents & ants (seed-eaters)

3. Character displacement → Galapagos Finches

4. Character release → pigeons in S.E. Asian islands

5. Abrupt species changes along environmental gradients → N. Guinea Warblers

What pattern