Biological Evolution and Diversity of Life

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which mechanism of evolution is primarily driven by mate selection?

Sexual selection (correct)

Gene flow

Genetic drift

Natural selection

What is the primary purpose of variation in natural selection?

To increase competition within species

To ensure altruism among individuals

To enhance survival chances of certain traits (correct)

To limit genetic drift effects

Which of the following statements does NOT support Darwin's theory of natural selection?

Variation is heritable.

Populations have unlimited resources. (correct)

Competition for resources occurs.

Individuals better adapted are likely to survive.

What did Gregor Mendel's research primarily contribute to our understanding of?

Inheritance patterns of traits Signup and view all the answers

How do genes influence an organism's characteristics?

By encoding instructions for protein synthesis Signup and view all the answers

Which pillar of natural selection is associated with the idea that certain traits provide an advantage in reproduction?

Sexual dimorphism Signup and view all the answers

What key factor is necessary for differential reproductive success to occur according to natural selection?

Heritable variation among individuals Signup and view all the answers

What does the comparative approach in comparative evolutionary psychology primarily aim to achieve?

To understand the origins of human behavior through comparisons with other species Signup and view all the answers

Which factor is most likely to influence mate preferences in evolutionary psychology according to the parental investment theory?

The gender that invests more in offspring being more selective in mate choice Signup and view all the answers

What is a primary difference between evolutionary psychology and social psychology regarding sex differences in mate preferences?

Evolutionary psychology focuses on genetic factors while social psychology emphasizes learned behaviors Signup and view all the answers

How does MHC compatibility relate to mate choice in humans?

Women prefer MHC-dissimilar partners because it signals better immune function Signup and view all the answers

What does the parasite theory suggest about attraction in sexual selection?

Signs of a strong immune system are attractive because they indicate health Signup and view all the answers

What is the primary focus of evolutionary psychology?

Examining the design of the human mind shaped by evolution Signup and view all the answers

Which factor is NOT considered part of sexual selection?

Gene flow Signup and view all the answers

What does biological fitness primarily measure?

Number of copies of genes passed to future generations Signup and view all the answers

What is a mismatch example related to diet in the context of evolutionary psychology?

Desire for energy-dense foods despite modern health issues Signup and view all the answers

Which principle of evolutionary psychology suggests that different neural circuits deal with specific adaptive problems?

Different neural circuits are specialized for solving varied problems Signup and view all the answers

What role does the environment of evolutionary adaptiveness (EEA) play in human behavior?

It reflects the conditions under which our ancestors evolved Signup and view all the answers

Which of the following is a criticism of evolutionary psychology?

It uses backward inferences that are difficult to test Signup and view all the answers

What aspect of the human experience is compared to a 'camping trip' lasting a lifetime?

Adaptation to ancestral living conditions Signup and view all the answers

Which of the following is NOT a prediction related to aggression in evolutionary psychology?

Promoting unselfish resource sharing Signup and view all the answers

What is the significance of the cognitive revolution in human evolution?

It signifies a dramatic increase in cognitive abilities among Homo sapiens Signup and view all the answers

Study Notes

Diversity of Life on Earth

Earth is home to approximately 8.7 million species.
Explaining this vast diversity with a coherent theory has been challenging.
Debates regarding natural selection continue.

Mechanisms of Biological Evolution

Five key mechanisms: natural selection, sexual selection, genetic drift, gene flow, and mutation.

Observations Before Darwin & Wallace

Change occurs over time.
Traits/characteristics have apparent purposes.

Darwin & Wallace's Explanatory Challenge

Understanding why change occurs.
Explaining how new species emerge.
Uncovering the function of traits.

The Origin of Species (Darwin, 1859)

Natural Selection's Three Pillars:
- Competition: Limited resources lead to a struggle for existence; unchecked populations grow exponentially.
- Variation: Individuals differ in their ability to compete; selection favors variations offering advantages. Individuals best suited to their environment are more likely to survive.
- Heritability: Variations are inheritable; differential reproductive success drives progressive population evolution.

Natural Selection Scrutinized

Exponential Population Growth: Confirmed.
Sufficient Time: Confirmed.
Heritability of Variation: Confirmed.
Sexual Dimorphism: Some traits appear to have no survival benefit but provide reproductive advantage (e.g., mating).

Genes

Genes influence physical traits and bodily functions; they encode proteins.
Proteins form body structures and facilitate life processes.
Genes are found on DNA (deoxyribonucleic acid) strands.
Gregor Mendel (1865): Organisms inherit two versions of each gene (alleles), one from each parent.
DNA replicates and is passed to offspring.
Genotype: genetic makeup.
Phenotype: observable traits.
Sources of Genetic Variation: sexual reproduction, mutation, genetic drift, gene flow.

The Selfish Gene

Gene is the unit of selection in biological evolution, not the individual or the trait.
Genes are "self-interested," striving to increase their representation in future generations.
Biological fitness: number of gene copies passed on.

Sexual Selection

Intersexual Selection: Preferential mate choice, often female choice influenced by gametic investment.
Intrasexual Selection: Competition within the same sex (e.g., combat).

The Evolution of the Human Species

Hunter-Gatherer Era: Homo sapiens (200,000 years ago – present).
Cognitive Revolution: 70,000 years ago.
Industrial Revolution: 200 years ago.
Digital Revolution: 20 years ago.
Lived in family groups; likely egalitarian; division of labor; high child mortality but potentially long lifespan.
Evolution, genes, psychology, cognition, behavior, learning, and culture are intricately linked.

Evolutionary Psychology (EP)

Seeks to understand the design of the human mind.
Applies to various psychological domains.
The mind is a collection of information-processing mechanisms designed by natural selection to solve problems faced by hunter-gatherer ancestors.

Five Principles of Evolutionary Psychology

The brain is a physical system governed by physical laws.
Neural circuits were designed by natural selection to solve ancestral problems.
Much of mental functioning is hidden from conscious awareness.
Specialized circuits are designed for specific adaptive problems.
Our modern brains contain a "Stone Age mind."

Environment of Evolutionary Adaptedness (EEA)

Mismatch Example 1 (Fear): Ancestral phobias (e.g., snakes, spiders) are prevalent; modern fears (e.g., cars, guns) less so, despite higher modern dangers.
Mismatch Example 2 (Diet): Craving high-energy foods is adaptive for ancestral environments; modern environments provide excess access to these foods contributing to health problems.

Evolutionary Psychology Examples

Aggression: Psychological mechanisms underlying aggression are context-dependent solutions to ancestral adaptive problems.

Criticism of Evolutionary Psychology

Methodology: Difficulties in testing backward inferences, "just-so stories," uncertainty about EEA pressures.
Interpretation: Concerns about eugenics, feminism, and potentially deterministic views.

Comparative Evolutionary Psychology

Addresses EP limitations by studying extant species, human cultural groups, and developmental stages.
Aims to improve understanding of human behavior through comparisons with other species.
Methodological Perspectives: Developmental, phylogenetic, and cross-cultural analyses.
Comparative Approach Benefits: Distinguishing innate versus learned cognition.

Parental Investment Theory

Parental investment: Investment in offspring that raises offspring's chances of survival and reproductive success.
Costs for the parent to invest in others.
Relative larger female gametes, more female investment in both mating and rearing.
The sex investing more is pickier.

Mate Preferences - Evolutionary Approach

Sex differences in mating preferences are tested across cultures.
Males value reproductive capacity more, females value resource acquisition more(David Buss, 1989, study).

Mate Preferences - Face and Odor Preferences

Averageness hypothesis, masculinity preferences, MHC compatibility.
MHC (major histocompatibility complex)-dissimilarity preference for immunity and odor in potential partners.

Evolutionary vs social psychology:
- EP: psychological sex differences adapt from evolutionary pressures
- Social psychology: social structure shapes psychological sex differences
Culture and social impacts behaviors.
Individuals seek mates fitting into their social role.

Gender Equality

Gender differences in mate preferences are smaller in nations with more gender parity.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the fascinating mechanisms of biological evolution and the vast diversity of life on Earth. This quiz covers key concepts from natural selection to the theories proposed by Darwin and Wallace. Test your knowledge on the evolution of species and their traits.