Darwin and Lamarck: Evolution Theories

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which ship did Charles Darwin sail on during his famous journey?

The Discovery

The Beagle (correct)

The Endeavour

The Challenger

Lamarck and Darwin had identical views on how evolution occurs.

False

What is the ultimate source of variation in a population?

Mutation

_ structures are characteristics inherited from a common ancestor, while _ structures serve similar functions but do not share a common ancestor.

Homologous, analogous Signup and view all the answers

Match the following types of evolution with their definitions:

Microevolution = Small changes within a population over time Macroevolution = Large-scale evolutionary changes that occur over time Allopatric speciation = Speciation that occurs due to geographic separation Sympatric speciation = Speciation that occurs without geographic separation Signup and view all the answers

Which mechanism of evolution is primarily responsible for increasing a population's fit to its environment?

Natural Selection Signup and view all the answers

What are vestigial structures? Provide an example.

Vestigial structures are remnants of organs or structures that had a function in early ancestors but are reduced or functionless in current organisms. An example is the human appendix. Signup and view all the answers

Eukaryotic organisms evolved through a process known as endosymbiosis.

True Signup and view all the answers

Which genus of protists is responsible for malaria?

Plasmodium Signup and view all the answers

Red tides are caused by certain types of fungi.

False Signup and view all the answers

What is the advantage of vascular tissue in plants?

It allows for the efficient transport of water and nutrients throughout the plant. Signup and view all the answers

The symbiosis between fungi and algae or cyanobacteria is called a __________.

lichens Signup and view all the answers

Match the following plant types with their characteristics:

Gymnosperms = Non-flowering seed plants like pine trees Angiosperms = Flowering plants that produce seeds Bryophytes = Non-vascular plants like mosses Seedless Vascular Plants = Plants that reproduce via spores like ferns Signup and view all the answers

What is a main characteristic of fungi?

They are heterotrophic and absorb nutrients. Signup and view all the answers

All plants are vascular, meaning they have specialized tissues for transporting water and nutrients.

False Signup and view all the answers

What does the term 'sporophyte' refer to in the plant life cycle?

The diploid generation that produces spores through meiosis. Signup and view all the answers

Study Notes

Charles Darwin and Lamarck

Charles Darwin proposed the theory of evolution by natural selection.
Jean-Baptiste Lamarck proposed a theory of evolution based on the inheritance of acquired characteristics.
Both Darwin and Lamarck believed that species changed over time, but they differed in their explanations for how this occurred.
Darwin argued that individuals with traits that made them better suited to their environment would be more likely to survive and reproduce, passing their advantageous traits to their offspring.
Lamarck believed that organisms could acquire traits during their lifetime, such as larger muscles from exercise, and pass these traits down to their offspring.

Darwin's Voyage

Darwin sailed on the HMS Beagle during his famous voyage.
Darwin studied finches on the Galapagos Islands, observing variations in their beak shapes.
He concluded that the different beak shapes were adaptations to different food sources, supporting his theory of natural selection.

Evolutionary Concepts

Variation refers to the differences among individuals in a population.
Mutation is the ultimate source of variation.
Adaptation is a trait that increases an organism's fitness in a particular environment.
Divergent evolution occurs when two or more species evolve from a common ancestor in different directions due to different selective pressures.
Convergent evolution occurs when two species that are not closely related evolve similar traits because they are subjected to similar environmental pressures.
Homologous structures are structures that share a common ancestry but have different functions due to divergent evolution.
Analogous structures are structures that have similar functions but have different ancestries due to convergent evolution.

Evolutionary Processes

Microevolution refers to changes in allele frequencies within a population over time.
Macroevolution refers to large-scale evolutionary changes, such as the emergence of new species.
Genotypic change indicates a change in the genetic makeup of an organism.
Phenotypic change refers to a change in the observable characteristics of an organism.
Gene pool is the total collection of genes in a population.
Mechanisms of evolution:
- Natural Selection: Organisms with traits that increase their fitness are more likely to survive and reproduce.
- Genetic Drift: Random changes in allele frequencies due to chance events.
- Gene Flow: The movement of genes between populations.
- Mutation: Changes in DNA sequences.
- Non-random mating: Individuals with certain traits are more likely to mate with each other.

Evidence for Evolution

Fossil Record: Preserved remains or traces of organisms from past geological epochs.
Biogeography: The distribution of species around the world.
Homology: Similarities in anatomical structures due to shared ancestry.
Embryology: Similarities in embryonic development among different species.
Molecular biology: Comparisons of DNA and protein sequences.
Vestigial structures: Reduced or non-functional structures that were present and functional in ancestral organisms.

Speciation

Speciation is the process by which new species arise.
Allopatric speciation occurs when two populations are geographically isolated and evolve independently.
Sympatric speciation occurs when two populations evolve independently within the same geographic area.
Evolution can occur in the absence of geographic speciation, due to factors such as polyploidy, disruptive selection, and reproductive isolation.

Domains of Life

Three domains of life: Bacteria, Archaea, Eukarya.
Humans belong to the domain Eukarya.
Taxonomic levels: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Binomial nomenclature: A two-part naming system for species, using the genus and species names.

Phylogenetic Trees

Phylogenetic trees depict evolutionary relationships among organisms.
Clade: A group of organisms that includes a common ancestor and all of its descendants.
Cladistics: A method of classifying organisms based on shared derived characteristics.
Monophyletic grouping: A group of organisms that includes all of the descendants of a common ancestor.
Shared ancestral characteristic: A trait present in the ancestor of a group.
Shared derived characteristic: A trait that is unique to a particular group of organisms.

Prokaryotes

Prokaryotes are single-celled organisms that lack a nucleus and other membrane-bound organelles.
Characteristics: Simple structure, small size, diverse metabolism, asexual reproduction.
Early prokaryotic organisms were successful because they were able to adapt to a wide range of environments.
Cyanobacteria are photosynthetic prokaryotes that produce oxygen.
Gram staining: A technique used to differentiate bacteria based on their cell wall structure.
Gram-positive bacteria have a thick peptidoglycan layer in their cell walls.
Gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane.
Pathogenic: Capable of causing disease.
Transformation: The uptake of naked DNA from the environment.
Transduction: The transfer of DNA between bacteria via viruses.
Conjugation: The transfer of DNA between bacteria through direct contact.
Overusing antibiotics can lead to antibiotic resistance.
Helpful bacteria are involved in processes such as nitrogen fixation, food digestion, and the production of antibiotics.

Eukaryotes

Eukaryotes are organisms that have a nucleus and other membrane-bound organelles.
Originated through endosymbiosis, where prokaryotic cells were engulfed and became organelles.
Protists are a diverse group of eukaryotic organisms that are not plants, animals, or fungi. They are not a true monophyletic grouping.
3 main protist categories: Algae, Protozoa, Slime molds.
Multicellular protists: Some algae.
Malaria is caused by the protist Plasmodium.
Red tides are caused by a bloom of certain types of algae.
Potato blight is caused by the protist Phytophthora infestans.

Fungi

Fungi are heterotrophic organisms that obtain nutrients by absorbing organic matter from their surroundings.
Saprobes: Fungi that feed on dead organic matter.
Single-celled fungi: Yeast is used in baking.
Symbiosis: A close relationship between two different species.
Lichen: A symbiotic relationship between a fungus and either algae or cyanobacteria. The fungus provides structure and protection, and the algae or cyanobacteria provide food.
Mycorrhizae: A symbiotic relationship between a fungus and the roots of plants. The fungus helps the plant absorb nutrients, and the plant provides food for the fungus.

Plants

General characteristics: Multicellular, photosynthetic, eukaryotic, have cell walls made of cellulose.
Adaptations for terrestrial life: Roots for anchoring and water absorption, vascular tissue for transporting water and nutrients, cuticle to prevent water loss, stomata for gas exchange.
Challenges of a terrestrial environment: Water loss, gravity, UV radiation.
Basic plant life cycle:
- Sporophyte (diploid): Produces spores by meiosis.
- Gametophyte (haploid): Produces gametes by mitosis.
- Gametes: Sperm and egg.
- Spores: Haploid cells that can develop into a new gametophyte.
Vascular plants: Have vascular tissue for transporting water and nutrients.
Non-vascular plants: Lack vascular tissue and are typically small and live in moist environments.
Xylem: Transports water and minerals from roots to leaves.
Phloem: Transports sugars from leaves to other parts of the plant.
Bryophytes: Non-vascular plants (e.g., mosses, liverworts, hornworts).
Seedless vascular plants: Ferns, horsetails, whisk ferns.
Seed: A structure that contains an embryo and food supply, protected by a seed coat.
Gymnosperms: "Naked seed" plants (e.g., conifers, cycads, ginkgoes).
Angiosperms: "Flowering" plants (e.g., grasses, trees, flowers).
Flower anatomy:
- Sepals: Protect the flower bud.
- Petals: Attract pollinators.
- Stamens: Produce pollen.
- Pistil: Contains the ovary, stigma, and style.
Monocots: Have one cotyledon, parallel leaf veins, floral parts in multiples of 3.
Eudicots: Have two cotyledons, netted leaf veins, floral parts in multiples of 4 or 5.

Animals

General characteristics: Multicellular, eukaryotic, heterotrophic, lack cell walls, have specialized tissues, are motile (able to move).
Organization of animal groupings:
- Presence of true tissues: Sponges lack true tissues, while other animals have them.
- Symmetry: Radial symmetry (cnidarians) or bilateral symmetry (most other animals).
- Protostome vs deuterostome: Based on embryonic development.
Symmetry:
- Radial symmetry: Can be divided into equal halves in multiple planes.
- Bilateral symmetry: Can be divided into equal halves along a single plane.
Acoelomate: Lack a body cavity.
Pseudocoelomate: Have a body cavity that is not completely lined by mesoderm.
Coelomate: Have a body cavity that is completely lined by mesoderm.
Protostome: The mouth develops from the blastopore.
Deuterostome: The anus develops from the blastopore.
Cephalization: The concentration of sensory organs and nerve cells at the anterior end of the body.

Animal Groups

Porifera: Sponges; lack true tissues, have pores for water flow, filter feeders.
Cnidaria: Jellyfish, corals, hydras; radial symmetry, have stinging cells called cnidocytes.
Platyhelminthes: Flatworms; bilateral symmetry, acoelomate, parasitic or free-living.
Nematoda: Roundworms; bilateral symmetry, pseudocoelomate, parasitic or free-living.

Studying That Suits You

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

Description

This quiz explores the contrasting theories of evolution proposed by Charles Darwin and Jean-Baptiste Lamarck. It covers Darwin's natural selection and Lamarck's idea of acquired characteristics, as well as key concepts from Darwin's voyage on the HMS Beagle. Test your knowledge on these foundational ideas in evolutionary biology.