DOI: 10.5061/dryad.kprr4xhdc
title: Data from: A demographic assessment of the Lansing Effect in duckweed (Lemna turionifera Landolt)

description: The Lansing Effect is the propensity for the offspring of older parents to
 have shorter lifespans than the offspring of younger parents. A recent
 review identified two demographic patterns that can produce the Lansing
 Effect: (1) a greater offspring mortality rate at all offspring ages in
 offspring of older versus younger parents (greater initial mortality
 parameter); and (2) an offspring mortality rate that increases more
 rapidly with offspring age in offspring of older versus younger parents
 (greater mortality rate parameter). Here, we report on a longitudinal
 study designed to investigate these patterns, using the duckweed Lemna
 turionifera. We tracked asexually produced offspring that detached from
 parents that were comparatively young versus old (first versus fifth
 offspring, respectively). Offspring of older parents lived 15% shorter, on
 average than offspring of younger parents, providing evidence of the
 Lansing Effect. A model-selection approach revealed that the difference
 between survival curves of the first versus fifth offspring was mainly
 attributable to greater initial mortality in the fifth compared to the
 first offspring, though alternative models also received some support. Our
 study provides a demographic explanation for the Lansing Effect
 in L. turionifera in particular and provides a method for
 assessing the survival patterns underpinning the Lansing Effect in
 general.
description: # Data from: A demographic assessment of the Lansing Effect in duckweed
 (*Lemna turionifera* Landolt)
 [https://doi.org/10.5061/dryad.kprr4xhdc](https://doi.org/10.5061/dryad.kprr4xhdc) Daily observations of the number of offspring produced by the first and fifth offspring of the duckweed *Lemna turionifera*. ## Description of the data and file structure There is one data file: "LEData_Raw.csv". It has 392 rows (not including the header row), corresponding to individual experimental subjects. It has 92 columns, corresponding to experimental subjects' traits and data collection: | Column number | Column name | Column description | | :------------ | :---------------------------------- | :------------------------------------------------------------------------------------------------- | | 1 | No. | Original row number (used for randomization purposes; "Removed" = plant removed from experiment\*) | | 2 | ident | Unique subject name of an individual focal plant (i.e., each row corresponds to one subject) | | 3 | birth.order | Birth order ("B1" = first offspring; "B5" = fifth offspring) | | 4 | date.birth | Date of birth (MMM.DD.YYYY) | | 5 | date.last.repro | Date of last reproduction (MMM.DD.YYYY) | | 6 | lifespan | Lifespan (in days) | | 7 | total.offspring | Total offspring produced | | 8 | offspring.attached.at.death | Number of offspring attached at death | | 9-92 | \[84 columns in format MMM.DD.YYYY] | Number of offspring detached on MMM.DD.YYYY | *Note: 'NA' values indicate missing data. In the case where the "No." column is "Removed", this is because the plant was removed from the experiment due to damage or contamination with microorganisms. Otherwise, it represents a value that does not exist (e.g., the number of offspring produced before an individual's birth or after its death). ## Code/Software There is one code file: "LELifespan_04.r". We ran the code in R version 4.4.0.