Evolution and Biodiversity Lecture Notes

A comprehensive review of evolution, natural selection, and biodiversity.

What is the definition of biological evolution?

Heritable change in one or more characteristics of a population or species from one generation to the next.

What are the two types of evolution discussed?

Microevolution (small-scale changes in a gene) and Macroevolution (large-scale changes leading to new species).

What is microevolution?

Small-scale evolution involving changes in gene frequencies in a population over time.

What is macroevolution?

Large-scale evolutionary changes that occur at or above the level of species.

What are Ernst Mayr’s five theories of Darwinism?

1) Perpetual change, 2) Common descent, 3) Multiplication of species, 4) Gradualism, 5) Natural selection.

What are the key conditions for natural selection?

Variation, heredity, and differential reproductive success.

What is adaptive radiation?

Production of several ecologically diverse species from a common ancestral species.

How did the Galápagos finches demonstrate natural selection?

Increased survival of large-beaked finches during a drought when small seeds were scarce.

What evidence supports the theory of evolution through fossil records?

Fossils show gradual change over time and include transitional forms.

What is the significance of biogeography in evolution?

It studies the spatial distribution of species and suggests historical land connections.

What are homologies and their types?

Similarities due to shared ancestry; types include anatomical, developmental, and molecular homologies.

What is the Hardy-Weinberg equilibrium?

A model that describes the genetics of non-evolving populations.

What are the conditions for Hardy-Weinberg equilibrium?

No mutations, no natural selection, large population size, no migration, and random mating.

How does natural selection affect fitness?

Natural selection promotes beneficial heritable traits, increasing individuals' reproductive success.

What are the four patterns of natural selection?

Directional selection, stabilizing selection, disruptive selection, and balancing selection.

What is genetic drift?

Random changes in allele frequency in a population, pronounced in small populations.

What are vestigial structures?

Remnant structures that served a purpose in the organism’s ancestors but have lost their original function.

What influences the distribution of organisms in different ecosystems?

Abiotic factors like temperature, water availability, light, and nutrients.

How do humans impact ecosystems regarding biodiversity loss?

Through habitat destruction, introduction of species, overexploitation, and climate change.

What is the significance of keystone species?

Species that have a disproportionately large effect on their ecosystem's structure.

What is the role of primary producers in an ecosystem?

They convert energy from sunlight or inorganic substances into chemical energy through photosynthesis.

What is the difference between gross primary production (GPP) and net primary production (NPP)?

GPP is the total energy captured by producers, while NPP is the energy available to consumers after accounting for respiration.

What is the importance of the phosphorus cycle?

It deals with the movement of phosphorus through rocks, soil, water, and organisms, crucial for ecosystem productivity.

Define biodiversity.

The variety of life in the world or in a particular habitat or ecosystem.

What is the definition of biological evolution?

Heritable change in one or more characteristics of a population or species from one generation to the next.

What are the two types of evolution discussed?

Microevolution (small-scale changes in a gene) and Macroevolution (large-scale changes leading to new species).

What is microevolution?

Small-scale evolution involving changes in gene frequencies in a population over time.

What is macroevolution?

Large-scale evolutionary changes that occur at or above the level of species.

What are Ernst Mayr’s five theories of Darwinism?

1) Perpetual change, 2) Common descent, 3) Multiplication of species, 4) Gradualism, 5) Natural selection.

What are the key conditions for natural selection?

Variation, heredity, and differential reproductive success.

What is adaptive radiation?

Production of several ecologically diverse species from a common ancestral species.

How did the Galápagos finches demonstrate natural selection?

Increased survival of large-beaked finches during a drought when small seeds were scarce.

What evidence supports the theory of evolution through fossil records?

Fossils show gradual change over time and include transitional forms.

What is the significance of biogeography in evolution?

It studies the spatial distribution of species and suggests historical land connections.

What are homologies and their types?

Similarities due to shared ancestry; types include anatomical, developmental, and molecular homologies.

What is the Hardy-Weinberg equilibrium?

A model that describes the genetics of non-evolving populations.

What are the conditions for Hardy-Weinberg equilibrium?

No mutations, no natural selection, large population size, no migration, and random mating.

How does natural selection affect fitness?

Natural selection promotes beneficial heritable traits, increasing individuals' reproductive success.

What are the four patterns of natural selection?

Directional selection, stabilizing selection, disruptive selection, and balancing selection.

What is genetic drift?

Random changes in allele frequency in a population, pronounced in small populations.

What are vestigial structures?

Remnant structures that served a purpose in the organism’s ancestors but have lost their original function.

What influences the distribution of organisms in different ecosystems?

Abiotic factors like temperature, water availability, light, and nutrients.

How do humans impact ecosystems regarding biodiversity loss?

Through habitat destruction, introduction of species, overexploitation, and climate change.

What is the significance of keystone species?

Species that have a disproportionately large effect on their ecosystem's structure.

What is the role of primary producers in an ecosystem?

They convert energy from sunlight or inorganic substances into chemical energy through photosynthesis.

What is the difference between gross primary production (GPP) and net primary production (NPP)?

GPP is the total energy captured by producers, while NPP is the energy available to consumers after accounting for respiration.

What is the importance of the phosphorus cycle?

It deals with the movement of phosphorus through rocks, soil, water, and organisms, crucial for ecosystem productivity.

Define biodiversity.

The variety of life in the world or in a particular habitat or ecosystem.

What are the two common types of genetic drift?

1) Bottleneck effect: A sudden reduction in population size due to environmental events. 2) Founder effect: Occurs when a small group of individuals separates from a larger population to establish a new colony.

What is the difference between allopatric and sympatric speciation?

Allopatric speciation occurs due to geographic isolation, while sympatric speciation occurs without geographic barriers, often through polyploidy or sexual selection.

What are analogous structures?

Features in different species that have similar functions but evolved independently through convergent evolution rather than from a common ancestor.

What is the 10% rule in ecology?

A principle stating that only approximately 10\% of the energy at one trophic level is transferred to the next, with the rest lost as heat during metabolic processes.

What are the three main types of symbiotic relationships?

1) Mutualism: Both species benefit. 2) Commensalism: One species benefits while the other is unaffected. 3) Parasitism: One species benefits at the expense of the other.

What is sexual selection?

A form of natural selection where individuals with certain inherited characteristics are more likely than others to obtain mates, often leading to sexual dimorphism.

What are the major stages of the nitrogen cycle?

Nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.

What is the definition of biological evolution?

Heritable change in one or more characteristics of a population or species from one generation to the next.

What are the two types of evolution discussed?

Microevolution (small-scale changes in a gene) and Macroevolution (large-scale changes leading to new species).

What is microevolution?

Small-scale evolution involving changes in gene frequencies in a population over time.

What is macroevolution?

Large-scale evolutionary changes that occur at or above the level of species.

What are Ernst Mayr’s five theories of Darwinism?

1) Perpetual change, 2) Common descent, 3) Multiplication of species, 4) Gradualism, 5) Natural selection.

What are the key conditions for natural selection?

Variation, heredity, and differential reproductive success.

What is adaptive radiation?

Production of several ecologically diverse species from a common ancestral species.

How did the Galápagos finches demonstrate natural selection?

Increased survival of large-beaked finches during a drought when small seeds were scarce.

What evidence supports the theory of evolution through fossil records?

Fossils show gradual change over time and include transitional forms.

What is the significance of biogeography in evolution?

It studies the spatial distribution of species and suggests historical land connections.

What are homologies and their types?

Similarities due to shared ancestry; types include anatomical, developmental, and molecular homologies.

What is the Hardy-Weinberg equilibrium?

A model that describes the genetics of non-evolving populations.

What are the conditions for Hardy-Weinberg equilibrium?

No mutations, no natural selection, large population size, no migration, and random mating.

How does natural selection affect fitness?

Natural selection promotes beneficial heritable traits, increasing individuals' reproductive success.

What are the four patterns of natural selection?

Directional selection, stabilizing selection, disruptive selection, and balancing selection.

What is genetic drift?

Random changes in allele frequency in a population, pronounced in small populations.

What are vestigial structures?

Remnant structures that served a purpose in the organism’s ancestors but have lost their original function.

What influences the distribution of organisms in different ecosystems?

Abiotic factors like temperature, water availability, light, and nutrients.

How do humans impact ecosystems regarding biodiversity loss?

Through habitat destruction, introduction of species, overexploitation, and climate change.

What is the significance of keystone species?

Species that have a disproportionately large effect on their ecosystem's structure.

What is the role of primary producers in an ecosystem?

They convert energy from sunlight or inorganic substances into chemical energy through photosynthesis.

What is the difference between gross primary production (GPP) and net primary production (NPP)?

GPP is the total energy captured by producers, while NPP is the energy available to consumers after accounting for respiration.

What is the importance of the phosphorus cycle?

It deals with the movement of phosphorus through rocks, soil, water, and organisms, crucial for ecosystem productivity.

Define biodiversity.

The variety of life in the world or in a particular habitat or ecosystem.

What are the two common types of genetic drift?

1) Bottleneck effect: A sudden reduction in population size due to environmental events. 2) Founder effect: Occurs when a small group of individuals separates from a larger population to establish a new colony.

What is the difference between allopatric and sympatric speciation?

Allopatric speciation occurs due to geographic isolation, while sympatric speciation occurs without geographic barriers, often through polyploidy or sexual selection.

What are analogous structures?

Features in different species that have similar functions but evolved independently through convergent evolution rather than from a common ancestor.

What is the 10% rule in ecology?

A principle stating that only approximately 10\% of the energy at one trophic level is transferred to the next, with the rest lost as heat during metabolic processes.

What are the three main types of symbiotic relationships?

1) Mutualism: Both species benefit. 2) Commensalism: One species benefits while the other is unaffected. 3) Parasitism: One species benefits at the expense of the other.

What is sexual selection?

A form of natural selection where individuals with certain inherited characteristics are more likely than others to obtain mates, often leading to sexual dimorphism.

What are the major stages of the nitrogen cycle?

Nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.

What is convergent evolution?

The process where unrelated organisms independently evolve similar traits as a result of adapting to similar environments or ecological niches.

What is the Biological Species Concept?

A definition of species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring.

What is gene flow?

The movement of alleles between populations through the migration of individuals or gametes, which tends to reduce genetic differences.

What is the difference between pre-zygotic and post-zygotic barriers?

Pre-zygotic barriers prevent mating or fertilization between species, while post-zygotic barriers prevent a hybrid zygote from developing into a viable, fertile adult.

What is artificial selection?

A form of selection in which humans actively choose which individuals to breed based on desired phenotypic traits.

What is punctuated equilibrium?

An evolutionary model suggesting that species stay relatively unchanged for long periods, with brief intervals of rapid change during speciation.

What is a trophic level?

Each step in a food chain or food web, representing the