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
DNAdamage
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