Animals Form and Function

Cards (220)

  • The nervous system is responsible for receiving, processing, integrating, storing, transmitting, and responding to information from the environment.
  • Animal origins include diversity such as mammals, birds, fish, arthropods, insects, etc.
  • The two main goals in understanding the history of animal life are to reconstruct phylogeny and understand the processes that generate and maintain diverse species and adaptations throughout history.
  • Molluscs have a lot of described species, including snails, clams, squids.
  • More than a million described arthropods belong to the phylum with the most species.
  • Animals are multicellular, eukaryotic, heterotrophic, most are motile, and belong to a specific lineage.
  • The tree of life consists of three main branches: Bacteria, Archaea, and Eucarya.
  • Evolution is the survival and reproduction leading to evolution, with descent with modification: change in characteristics of a species over generations.
  • The mechanisms responsible for modification include natural selection, mutation, migration, and genetic drift.
  • Darwin and Wallace did not originate the idea of evolution, as early Greek philosophers suggested that life had a long history of change.
  • Lamarckism is the first complete hypothesis for the method of evolution, arguing that the inheritance of acquired characteristics leads to species change.
  • Homology: shared characters that are a result of common ancestry
  • Monophyletic: includes most recent common ancestor and all descendants of that ancestor
  • Comparative Morphology: compare shapes and sizes of organismal structures as well as their developmental origins
  • Comparative biochemistry: compares sequences of amino acids in proteins/nucleotides in DNA and RNA
  • Group has at least two separate evolutionary origins
  • Ancestral and descendant relationships among different characters or states of characters
  • Phylogenies have polarity
  • Hypothesis of recapitulation (biogenic law) → incorrect
  • Chromosomal banding patterns can be visualized
  • Comparative Cytology: examines variation in number shapes and size of chromosomes
  • Used to build phylogenetic trees
  • Ontogeny: developmental history of an organism over its lifetime
  • Synapomorphy: shared derived character between members of a clade
  • Maternal effects; developmental environment, nature vs nurture etc
  • Polyphyletic: Does not include the most recent common ancestor of all members of a group
  • DNA damage
  • Several ways to draw phylogenetic trees; information conveyed about relationships is the same
  • Karyotype: size, shape, and number of chromosomes in a sample of cells
  • Ethical issues
  • Systematics: the science of taxonomy which involves reconstruction of phylogenetic trees
  • To understand the polarity of a trait we first must determine which form of the character existed.
  • Sequence alignment arranges the DNA/RNA/amino acid to identify similarities and differences
  • Internal Node: Hypothetical common ancestor Terminal node: Descendants Outgroup: Root: where the phylogenetic trees starts - common ancestor of all species at branch tips is that closest to the root -
  • Homoplasy: (analogy) character similarity that is not a result of common ancestry (non-homologous)
  • During development animals go through forms that represent their evolutionary history.
  • De-Extinction: Can we bring back species?
  • Evolution is a variational process, not an individual process, and species change over time because something sorts among the variants in the original group.
  • Paraphyletic: includes most recent common ancestor of all members of a group and some but not all descendants
  • Efforts to bring back wooly mammoth by 2027