Skip to main content
Indietro

Chapters 19 - 20

I pulsanti di controllo sono stati cambiati in modalità "navigazione".
1/25

Termini in questo insieme (25)

  • What are the three key observations about life that support the theory of evolution?
    Organisms are well suited to their environments, there is unity among diverse life forms, and there is a rich diversity of life.
  • What was the pre-Darwinian worldview about species?
    Species were considered perfect, permanent, and specially created, fixed on a ladder of complexity, and unchanging over time.
  • What is the significance of fossils in evolutionary biology?
    Fossils provide evidence of past life forms, show gradual changes over time, and help understand extinction and speciation events.
  • What incorrect evolutionary mechanism did Lamarck propose?
    Lamarck proposed use and disuse and inheritance of acquired characteristics, suggesting organisms adapt during their lifetime and pass changes to offspring.
  • Why is Lamarck's theory of inheritance of acquired characteristics incorrect?
    Individual organisms cannot choose traits to change during their lifetime, and acquired traits are not genetically inherited.
  • What was Darwin's main focus during his voyage on the HMS Beagle?
    He studied adaptations that make species suited to their environment, including anatomical, physiological, and behavioral traits.
  • Who independently proposed natural selection alongside Darwin?
    Alfred Russel Wallace developed a hypothesis of natural selection nearly identical to Darwin’s.
  • What does 'descent with modification' mean according to Darwin?
    It means species change over time and share a common ancestor, with modifications accumulating through generations.
  • What is artificial selection and how did Darwin use it?
    Artificial selection is human-driven breeding for desired traits, used by Darwin as an analogy for natural selection.
  • What are Darwin’s two main observations for natural selection?
    1. Populations vary in inherited traits. 2. More offspring are produced than can survive.
  • What are Darwin’s two inferences from his observations on natural selection?
    1. Individuals with favorable traits survive and reproduce more. 2. Favorable traits accumulate in populations over time.
  • What key features are necessary for evolution by natural selection?
    Evolution acts on populations, not individuals, requires genetic variation, and depends on environmental selective pressures.
  • What is homology in evolutionary biology?
    Homology refers to similar anatomical structures due to common ancestry, such as vertebrate forelimbs.
  • What are vestigial structures?
    Vestigial structures are remnants of organs or structures that had a function in ancestors but are reduced or unused now.
  • What are analogous structures and how do they arise?
    Analogous structures have similar functions but different evolutionary origins, arising from convergent evolution.
  • What molecular evidence supports evolution?
    Almost all living organisms share common biochemistry such as ATP, DNA, and proteins.
  • What does the fossil record show about evolution?
    Fossils show a succession from simple to complex forms and provide transitional links between groups.
  • What is biogeography and how does it support evolution?
    Biogeography studies the geographic distribution of species, showing related species in nearby regions and endemic species.
  • What is phylogeny?
    Phylogeny is the evolutionary history of a species or group of species.
  • What is a phylogenetic tree?
    A diagram showing lines of descent from common ancestors and evolutionary relationships.
  • What is the difference between homologous and analogous structures?
    Homologous structures share a common ancestor, while analogous structures have similar function but different ancestry.
  • What is a clade in a cladogram?
    A clade is an evolutionary branch including a common ancestor and all its descendants.
  • What is maximum parsimony in phylogenetics?
    It is the principle of choosing the simplest evolutionary tree with the fewest changes.
  • What are molecular clocks?
    Molecular clocks estimate evolutionary time based on constant rates of genetic mutations.
  • How are scientific names formatted in binomial nomenclature?
    The genus name is capitalized and italicized, the species epithet is lowercase and italicized, e.g., Homo sapiens.