exam 1 concepts

What is the primary theme uniting all of biology?

Evolution, alongside concepts like cell theory and genetics.

What mechanism did Darwin provide for the concept of evolution?

Natural selection.

What term was used in the 18th-19th centuries to describe changes in lineages before the term 'evolution' was adopted?

Descriptive modification.

What is the preference in teaching approaches for evolutionary concepts?

Qualitative teaching approaches rather than solely quantitative.

Who developed the binomial nomenclature for classifying organisms?

Carolus Linnaeus.

What was one of James Hutton's contributions to evolutionary thought?

Proposed geological principles foundational for understanding Earth's change over time.

What idea did Jean Baptiste Lamarck propose regarding species change?

Species could change through mechanisms like usage and disuse of traits.

What was Charles Darwin's most significant contribution to evolutionary biology?

The mechanism of natural selection.

What was the purpose of Darwin's Voyage of the Beagle?

It was a survey mission that led to observations about nature and evidence for evolutionary change.

What drives the adaptation of organisms to their environment according to natural selection?

Environmental pressures.

What leads to competition for limited resources in a population?

Overproduction of offspring.

How does variation among individuals within a population affect survival?

It affects their chances of survival and reproduction.

What is the definition of fitness in the context of natural selection?

The ability of an organism to survive and reproduce in a given environment.

How can traits be advantageous in one environment but detrimental in another?

Fitness is defined by an organism's adaptations to its specific environment and the environmental pressures present.

What leads to significant species diversification over time?

Long-term adaptations due to natural selection.

What influence did Thomas Malthus have on Darwin's ideas?

Malthus's theory of population growth influenced Darwin's ideas about competition and survival due to resource limitations.

What does differential reproduction mean in the context of natural selection?

Not all organisms have equal success in leaving offspring.

What is an example of natural selection observed in Galapagos Finches?

Variation in beak shapes linked to available food sources.

How do adaptations help organisms over generations?

They help organisms become more specialized for their niche.

What is the relationship between inherited variations and natural selection?

Organisms change over time due to natural selection based on inherited variations.

What is an example of rapid variation under human selection compared to natural selection?

Dog breeds demonstrating rapid variation versus natural selection's slower process.

What is the role of environmental conditions in Darwin's foundational ideas?

They tie observations of survival and reproduction to adaptation.

What does the concept of fitness encompass in evolutionary biology?

It includes the ability to survive and reproduce based on adaptations to specific environmental pressures.

What is the cornerstone of biology that explains the interconnectedness of life?

Evolution through natural selection.

How does natural selection affect populations?

It affects individuals in a population, leading to organisms that are more likely to survive and reproduce leaving behind more offspring.

What example illustrates natural selection in Darwin's research?

Darwin's finches, where beak shapes correlate with feeding habits.

What drives adaptations in organisms according to the notes?

Food availability and metric pressures affecting food sources.

What is common ancestry in the context of evolution?

The hypothetical single ancestor species of fish that migrated to the Galapagos Islands and underwent adaptive changes.

How do different environments influence evolutionary adaptations?

Different environments on various islands lead to diverse adaptations among organisms.

What are the different beak shapes of finches adapted for?

Large beaks for seeds, smaller beaks for fruits, and longer beaks for insects.

What role does isolation on islands play in evolution?

It serves as a crucible for evolution, leading to speciation.

What is the difference between microevolution and macroevolution?

Microevolution refers to small, observable changes in populations, while macroevolution involves larger scale changes leading to new species.

What is fitness in the context of natural selection?

It refers to organisms that best match their environment surviving and reproducing more successfully.

What is artificial selection?

Human-induced changes in traits observed in domesticated species through selective breeding.

What does the case study of peppered moths illustrate?

A shift in coloration frequencies due to natural selection before and after industrialization.

How do honeycreepers in Hawaii exemplify adaptive evolution?

They show distinct beak adaptations due to environmental pressures, similar to Darwin's finches.

What is an example of rapid adaptation in bacteria?

Bacterial resistance to antibiotics due to rapid reproduction.

What does pesticide resistance in pests demonstrate?

Adaptive changes due to chemical exposure.

How do praying mantises demonstrate adaptation?

They exhibit camouflage to blend with their environments, enhancing survival.

What does natural selection exert pressure on?

Selection acts on already-existing traits in populations.

Who evolves, individuals or populations?

Populations evolve through generational changes.

What is the significance of the fossil record in evolution?

It provides direct evidence of changes in organisms over time.

What are transitional series in the fossil record?

Links between ancient organisms and modern species, showing adaptations over time.

What are vestigial structures?

Remnants of ancestral forms that no longer benefit fitness.

How do evolutionary processes enrich our understanding of biological sciences?

They explain the complex interactions and history of life on Earth.

What is functional anatomy?

The study of how anatomical structures relate to their functionality.

Why is functional anatomy important?

It allows inference about an organism's lifestyle based on its anatomy.

What do transitional series in evolution illustrate?

They show how organisms can be lined up to demonstrate evolution from one form to another, such as from terrestrial to aquatic mammals.

What is comparative anatomy?

The comparison of anatomical structures among different organisms.

Give an example of comparative anatomy.

The forelimbs of humans, cats, whales, and bats demonstrate functional adaptations to different lifestyles.

What are homologous structures?

Similar structures among different species due to common ancestry, such as the forelimb bones in mammals.

What is an example of homologous structures in tetrapods?

The basic forelimb structure, including the humerus, radius, and ulna, conserved across all tetrapods.

What are analogous structures?

Structures that serve similar functions but evolved independently, such as the wings of insects, birds, and bats.

What is the key difference between homologous and analogous structures?

Homologous structures indicate common ancestry, while analogous structures do not.

What is the current method of classification in evolutionary biology?

Classification is based on structural similarity and evolutionary relationships, distinguishing between homology and analogy.

What are vestigial structures?

Remnants of structures that indicate past adaptations, such as pelvic bones in whales.

What does embryology study in relation to evolutionary biology?

Embryology studies embryos, showing that closely related organisms have similar embryonic stages.

What misconception about embryology has been debunked?

The idea that ontogeny recapitulates phylogeny is no longer considered true.

What are phylogenetic trees?

Visual representations that show evolutionary relationships based on structures or genetic data.

How has molecular biology advanced the study of evolutionary relationships?

Advancements in computing have enhanced the ability to analyze numerous characteristics from various organisms.

What is the relationship between genotype and phenotype?

Changes in genotype often lead to changes in phenotype, though the relationship is not always straightforward.

What is noncoding DNA and its significance?

Noncoding DNA makes up about 75% of the human genome and is involved in regulation, challenging the notion that it is merely 'junk' DNA.

What are transposable elements?

Sections of DNA that can move around, influencing gene expression and evolution.

What are transposons?

Transposable elements that move via DNA intermediates and can be cut and pasted into different locations.

What are retrotransposons?

Transposable elements that use RNA intermediates and maintain copies at original sites, creating duplication.

What is the Hardy-Weinberg principle?

A tool to determine if evolutionary change is occurring within a population and predicts frequencies of different alleles.

What are the equilibrium conditions for Hardy-Weinberg equilibrium?

Large population size, no mutations, no natural selection, random mating, and no gene flow.

What are the real-world implications of the Hardy-Weinberg principle?

No natural population will maintain Hardy-Weinberg equilibrium due to frequent violations of the conditions.

What is natural selection?

Differential survivability where traits influence an organism's fitness relative to environmental pressures, resulting in increased frequency of advantageous traits.

What is genetic drift?

Random changes in allele frequencies within a population, disproportionately affecting small populations.

What is the Bottleneck Effect?

Occurs when a sudden reduction in population size drastically changes allele frequencies, akin to marbles being shaken from a bottle.

What happens to allele frequencies after a bottleneck event?

A population may lose certain alleles entirely, and survivors may have allele frequencies not representative of the original population.

What is the Founder Effect?

Happens when a small number of individuals start a new population, leading to allele frequencies that differ significantly from the original population.

Give an example of the Founder Effect.

Polydactyly is more common in the Amish population due to a limited number of founders carrying the gene.

What is gene flow?

The movement of individuals or gametes between populations, changing allele frequencies.

How can gene flow impact allele frequencies?

Even a single migrational event can alter allele frequencies, especially if the migrating alleles are beneficial in the new population.

What is non-random mating?

Preference in mate selection that can lead to skewed allele frequencies, challenging the Hardy-Weinberg assumption of equal reproductive success.

What is stabilizing selection?

Favors intermediate variants over extremes, promoting uniformity.

Provide an example of stabilizing selection.

Pocket mice in a habitat of uniform brown color would favor mice of similar mid-range colors.

What is directional selection?

Favors one extreme phenotype, shifting the population's traits in one direction.

Provide an example of directional selection.

After a fire that darkened the terrain, dark-colored pocket mice would be favored over lighter mice.

What is disruptive (diversifying) selection?

Favors extreme phenotypes at the expense of intermediate varieties, potentially leading to speciation.

Provide an example of disruptive selection.

Pocket mice that can adapt to both light and dark habitats, resulting in two separate populations adapting to each environment.

What role do mutations play in genetic variation?

Mutations are the only source for new alleles, leading to genetic variability.

What is heterozygote advantage?

When heterozygous individuals have higher fitness than homozygotes, such as in the case of sickle cell trait providing advantages against malaria.

What is sexual selection?

Leads to sexual dimorphism, where males and females exhibit different characteristics due to different selective pressures in mating.

How does natural selection affect variation?

Natural selection generally decreases variation while mutations and gene flow can introduce new alleles increasing variation.

What is the Biological Species Concept?

Defines species based on their ability to reproduce viable offspring, focusing on the inability to reproduce or produce viable offspring.

What are prezygotic barriers?

Barriers that prevent fertilization from occurring, including habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, and gametic isolation.

What are postzygotic barriers?

Barriers that occur after fertilization, such as reduced hybrid viability where hybrids fail to develop properly or are frail.

What is reduced hybrid fertility?

Hybrids are viable but sterile, such as mules, which are hybrids of donkeys and horses.

What is hybrid breakdown?

First-generation hybrids are viable, but subsequent generations are sterile.

What are the limitations of the Biological Species Concept?

It is not applicable to fossils (no living organisms to observe reproduction) and asexual organisms (no mating necessary).

What does the Morphological Species Concept focus on?

It focuses on structural features and is frequently used in paleontology to identify fossils based on shared derived characteristics.

What is emphasized by the Ecological Species Concept?

It emphasizes interactions with biotic and abiotic environments.

What is the basis of the Phylogenetic Species Concept?

It is based on phylogenetic analysis and examines shared derived characteristics to identify evolutionary lineages.

What is allopatric speciation?

It occurs due to geographic isolation, where organisms evolve independently due to separation by physical barriers.

What is sympatric speciation?

It occurs without geographic isolation, where populations overlap but do not interbreed due to differing habitats or behaviors.

What is an example of sympatric speciation in plants?

Plants can undergo polyploidy, leading to the formation of new species.

How can environmental changes affect speciation?

Environmental changes, such as climate change, can cause formerly separate populations to overlap, allowing for hybridization.