R/whale_brains.R

In ecoteach: Educational Datasets for Ecology and Agriculture

#' The Evolution of Hearing and Brain Size in Eocene Whales
#'
#' A dataset containing endocranial volume and body mass measurements for various cetacean 
#' (whale) species and other mammals. This dataset was compiled to study the evolution of 
#' hearing and brain size in Eocene whales. It includes both extant (living) and fossil 
#' species, with a focus on understanding how brain size evolved in relation to body mass 
#' and hearing adaptations across different taxonomic groups. The dataset is particularly 
#' valuable for teaching concepts in comparative anatomy, allometry, and cetacean evolution.
#'
#' Toothed whales (odontocetes) use high-frequency sounds to echolocate, differing 
#' significantly from baleen whales (mysticetes), which use low-frequency sound for 
#' long-distance communication. This dataset helps explore how hearing functioned in 
#' ancestral archaeocetes, and when the specializations of modern species arose.
#'
#' @format A data frame with 269 rows and 9 variables:
#' \describe{
#'   \item{family}{Taxonomic family of the species}
#'   \item{binomial_name}{Full taxonomic name for each species}
#'   \item{common_name}{Common name for each species (NA for most fossil species)}
#'   \item{endocranial_volume}{Endocranial volume in cubic centimeters (cc)}
#'   \item{brain_mass}{Brain mass in grams}
#'   \item{ocw_mm}{Occipital condyle width in millimeters}
#'   \item{body_mass}{Body mass in kilograms}
#'   \item{taxonomic_group}{Categorization as "Cetacean", "Hippopotamid", or "Other Mammal"}
#'   \item{time_period}{Classification as "Extant" (living) or "Fossil" species}
#' }
#' @source Peacock, John and Waugh, David and Bajpai, Sunil and Thewissen, JGM (2025). 
#'   The evolution of hearing and brain size in Eocene whales. Dryad Digital Repository. 
#'   \doi{10.5061/DRYAD.SF7M0CGH1}
#' @examples
#' \donttest{
#' # Load the dataset
#' data(whale_brains)
#' 
#' # Basic exploration
#' head(whale_brains)
#' summary(whale_brains)
#' 
#' # Compare brain mass across taxonomic groups
#' boxplot(whale_brains$brain_mass ~ whale_brains$taxonomic_group, 
#'         main = "Brain Mass by Taxonomic Group",
#'         ylab = "Brain Mass (g)", log = "y")
#' 
#' # Look at the relationship between brain mass and body mass
#' # Using log scales to show allometric relationships
#' plot(whale_brains$body_mass, whale_brains$brain_mass, 
#'      log = "xy", col = as.numeric(whale_brains$taxonomic_group),
#'      pch = 16, main = "Brain Mass vs. Body Mass",
#'      xlab = "Body Mass (kg)", ylab = "Brain Mass (g)")
#' legend("topleft", legend = levels(whale_brains$taxonomic_group), 
#'        col = 1:3, pch = 16)
#'        
#' # Compare fossil and extant cetaceans
#' cetaceans <- subset(whale_brains, taxonomic_group == "Cetacean")
#' boxplot(cetaceans$brain_mass ~ cetaceans$time_period,
#'         main = "Brain Mass in Fossil vs. Extant Cetaceans",
#'         ylab = "Brain Mass (g)", log = "y")
#' }
"whale_brains"